ActiveState!

ActivePerl Documentation
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* Getting Started
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* ActivePerl FAQ
    * Introduction
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 Config - access Perl configuration information


NAME

Config - access Perl configuration information


SUPPORTED PLATFORMS

  • Linux
  • Solaris
  • Windows

SYNOPSIS

    use Config;
    if ($Config{'cc'} =~ /gcc/) {
        print "built by gcc\n";
    }
    use Config qw(myconfig config_sh config_vars);
    print myconfig();
    print config_sh();
    config_vars(qw(osname archname));


DESCRIPTION

The Config module contains all the information that was available to the Configure program at Perl build time (over 900 values).

Shell variables from the config.sh file (written by Configure) are stored in the readonly-variable %Config, indexed by their names.

Values stored in config.sh as 'undef' are returned as undefined values. The perl exists function can be used to check if a named variable exists.

myconfig()
Returns a textual summary of the major perl configuration values. See also -V in Switches in the perlrun manpage.

config_sh()
Returns the entire perl configuration information in the form of the original config.sh shell variable assignment script.

config_vars(@names)
Prints to STDOUT the values of the named configuration variable. Each is printed on a separate line in the form:
  name='value';

Names which are unknown are output as name='UNKNOWN';. See also -V:name in Switches in the perlrun manpage.


EXAMPLE

Here's a more sophisticated example of using %Config:

    use Config;
    use strict;
    my %sig_num;
    my @sig_name;
    unless($Config{sig_name} && $Config{sig_num}) {
        die "No sigs?";
    } else {
        my @names = split ' ', $Config{sig_name};
        @sig_num{@names} = split ' ', $Config{sig_num};
        foreach (@names) {
            $sig_name[$sig_num{$_}] ||= $_;
        }   
    }
    print "signal #17 = $sig_name[17]\n";
    if ($sig_num{ALRM}) { 
        print "SIGALRM is $sig_num{ALRM}\n";
    }


WARNING

Because this information is not stored within the perl executable itself it is possible (but unlikely) that the information does not relate to the actual perl binary which is being used to access it.

The Config module is installed into the architecture and version specific library directory ($Config{installarchlib}) and it checks the perl version number when loaded.

The values stored in config.sh may be either single-quoted or double-quoted. Double-quoted strings are handy for those cases where you need to include escape sequences in the strings. To avoid runtime variable interpolation, any $ and @ characters are replaced by \$ and \@, respectively. This isn't foolproof, of course, so don't embed \$ or \@ in double-quoted strings unless you're willing to deal with the consequences. (The slashes will end up escaped and the $ or @ will trigger variable interpolation)


GLOSSARY

Most Config variables are determined by the Configure script on platforms supported by it (which is most UNIX platforms). Some platforms have custom-made Config variables, and may thus not have some of the variables described below, or may have extraneous variables specific to that particular port. See the port specific documentation in such cases.

_

_a
From Unix.U:

This variable defines the extension used for ordinary libraries. For unix, it is .a. The . is included. Other possible values include .lib.

_exe
From Unix.U:

This variable defines the extension used for executable files. For unix it is empty. Other possible values include .exe.

_o
From Unix.U:

This variable defines the extension used for object files. For unix, it is .o. The . is included. Other possible values include .obj.

a

afs
From afs.U:

This variable is set to true if AFS (Andrew File System) is used on the system, false otherwise. It is possible to override this with a hint value or command line option, but you'd better know what you are doing.

alignbytes
From alignbytes.U:

This variable holds the number of bytes required to align a double-- or a long double when applicable. Usual values are 2, 4 and 8. The default is eight, for safety.

ansi2knr
From ansi2knr.U:

This variable is set if the user needs to run ansi2knr. Currently, this is not supported, so we just abort.

aphostname
From d_gethname.U:

This variable contains the command which can be used to compute the host name. The command is fully qualified by its absolute path, to make it safe when used by a process with super-user privileges.

api_revision
From patchlevel.U:

The three variables, api_revision, api_version, and api_subversion, specify the version of the oldest perl binary compatible with the present perl. In a full version string such as 5.6.1, api_revision is the 5. Prior to 5.5.640, the format was a floating point number, like 5.00563.

        F<perl.c>:incpush() and F<lib/lib.pm> will automatically search in
        $F<sitelib/.>. for older directories back to the limit specified
by these api_ variables.  This is only useful if you have a
perl library directory tree structured like the default one.
See C<INSTALL> for how this works.  The versioned site_perl
directory was introduced in 5.005, so that is the lowest
possible value.  The version list appropriate for the current
system is determined in F<inc_version_list.U>.
        C<XXX> To do:  Since compatibility can depend on compile time
        options (such as bincompat, longlong, F<etc.>) it should
(perhaps) be set by Configure, but currently it isn't.
Currently, we read a hard-wired value from F<patchlevel.h>.
Perhaps what we ought to do is take the hard-wired value from
F<patchlevel.h> but then modify it if the current Configure
options warrant.  F<patchlevel.h> then would use an #ifdef guard.

api_subversion
From patchlevel.U:

The three variables, api_revision, api_version, and api_subversion, specify the version of the oldest perl binary compatible with the present perl. In a full version string such as 5.6.1, api_subversion is the 1. See api_revision for full details.

api_version
From patchlevel.U:

The three variables, api_revision, api_version, and api_subversion, specify the version of the oldest perl binary compatible with the present perl. In a full version string such as 5.6.1, api_version is the 6. See api_revision for full details. As a special case, 5.5.0 is rendered in the old-style as 5.005. (In the 5.005_0x maintenance series, this was the only versioned directory in $sitelib.)

api_versionstring
From patchlevel.U:

This variable combines api_revision, api_version, and api_subversion in a format such as 5.6.1 (or 5_6_1) suitable for use as a directory name. This is filesystem dependent.

ar
From Loc.U:

This variable is used internally by Configure to determine the full pathname (if any) of the ar program. After Configure runs, the value is reset to a plain ar and is not useful.

archlib
From archlib.U:

This variable holds the name of the directory in which the user wants to put architecture-dependent public library files for $package. It is most often a local directory such as /usr/local/lib. Programs using this variable must be prepared to deal with filename expansion.

archlibexp
From archlib.U:

This variable is the same as the archlib variable, but is filename expanded at configuration time, for convenient use.

archname64
From use64bits.U:

This variable is used for the 64-bitness part of $archname.

archname
From archname.U:

This variable is a short name to characterize the current architecture. It is used mainly to construct the default archlib.

archobjs
From Unix.U:

This variable defines any additional objects that must be linked in with the program on this architecture. On unix, it is usually empty. It is typically used to include emulations of unix calls or other facilities. For perl on OS/2, for example, this would include os2/os2.obj.

awk
From Loc.U:

This variable is used internally by Configure to determine the full pathname (if any) of the awk program. After Configure runs, the value is reset to a plain awk and is not useful.

b

baserev
From baserev.U:

The base revision level of this package, from the .package file.

bash
From Loc.U:

This variable is defined but not used by Configure. The value is a plain '' and is not useful.

bin
From bin.U:

This variable holds the name of the directory in which the user wants to put publicly executable images for the package in question. It is most often a local directory such as /usr/local/bin. Programs using this variable must be prepared to deal with ~name substitution.

bincompat5005
From bincompat5005.U:

This variable contains y if this version of Perl should be binary-compatible with Perl 5.005.

binexp
From bin.U:

This is the same as the bin variable, but is filename expanded at configuration time, for use in your makefiles.

bison
From Loc.U:

This variable is defined but not used by Configure. The value is a plain '' and is not useful.

byacc
From Loc.U:

This variable is used internally by Configure to determine the full pathname (if any) of the byacc program. After Configure runs, the value is reset to a plain byacc and is not useful.

byteorder
From byteorder.U:

This variable holds the byte order. In the following, larger digits indicate more significance. The variable byteorder is either 4321 on a big-endian machine, or 1234 on a little-endian, or 87654321 on a Cray ... or 3412 with weird order !

c

c
From n.U:

This variable contains the \c string if that is what causes the echo command to suppress newline. Otherwise it is null. Correct usage is $echo $n ``prompt for a question: $c''.

castflags
From d_castneg.U:

This variable contains a flag that precise difficulties the compiler has casting odd floating values to unsigned long: 0 = ok 1 = couldn't cast < 0 2 = couldn't cast >= 0x80000000 4 = couldn't cast in argument expression list

cat
From Loc.U:

This variable is used internally by Configure to determine the full pathname (if any) of the cat program. After Configure runs, the value is reset to a plain cat and is not useful.

cc
From cc.U:

This variable holds the name of a command to execute a C compiler which can resolve multiple global references that happen to have the same name. Usual values are cc, Mcc, cc -M, and gcc.

cccdlflags
From dlsrc.U:

This variable contains any special flags that might need to be passed with cc -c to compile modules to be used to create a shared library that will be used for dynamic loading. For hpux, this should be +z. It is up to the makefile to use it.

ccdlflags
From dlsrc.U:

This variable contains any special flags that might need to be passed to cc to link with a shared library for dynamic loading. It is up to the makefile to use it. For sunos 4.1, it should be empty.

ccflags
From ccflags.U:

This variable contains any additional C compiler flags desired by the user. It is up to the Makefile to use this.

ccsymbols
From Cppsym.U:

The variable contains the symbols defined by the C compiler alone. The symbols defined by cpp or by cc when it calls cpp are not in this list, see cppsymbols and cppccsymbols. The list is a space-separated list of symbol=value tokens.

cf_by
From cf_who.U:

Login name of the person who ran the Configure script and answered the questions. This is used to tag both config.sh and config_h.SH.

cf_email
From cf_email.U:

Electronic mail address of the person who ran Configure. This can be used by units that require the user's e-mail, like MailList.U.

cf_time
From cf_who.U:

Holds the output of the date command when the configuration file was produced. This is used to tag both config.sh and config_h.SH.

charsize
From charsize.U:

This variable contains the value of the CHARSIZE symbol, which indicates to the C program how many bytes there are in a character.

chgrp
From Loc.U:

This variable is defined but not used by Configure. The value is a plain '' and is not useful.

chmod
From Loc.U:

This variable is defined but not used by Configure. The value is a plain '' and is not useful.

chown
From Loc.U:

This variable is defined but not used by Configure. The value is a plain '' and is not useful.

clocktype
From d_times.U:

This variable holds the type returned by times(). It can be long, or clock_t on BSD sites (in which case <sys/types.h> should be included).

comm
From Loc.U:

This variable is used internally by Configure to determine the full pathname (if any) of the comm program. After Configure runs, the value is reset to a plain comm and is not useful.

compress
From Loc.U:

This variable is defined but not used by Configure. The value is a plain '' and is not useful.

C

CONFIGDOTSH
From Oldsyms.U:

This is set to true in config.sh so that a shell script sourcing config.sh can tell if it has been sourced already.

contains
From contains.U:

This variable holds the command to do a grep with a proper return status. On most sane systems it is simply grep. On insane systems it is a grep followed by a cat followed by a test. This variable is primarily for the use of other Configure units.

cp
From Loc.U:

This variable is used internally by Configure to determine the full pathname (if any) of the cp program. After Configure runs, the value is reset to a plain cp and is not useful.

cpio
From Loc.U:

This variable is defined but not used by Configure. The value is a plain '' and is not useful.

cpp
From Loc.U:

This variable is used internally by Configure to determine the full pathname (if any) of the cpp program. After Configure runs, the value is reset to a plain cpp and is not useful.

cpp_stuff
From cpp_stuff.U:

This variable contains an identification of the catenation mechanism used by the C preprocessor.

cppccsymbols
From Cppsym.U:

The variable contains the symbols defined by the C compiler when it calls cpp. The symbols defined by the cc alone or cpp alone are not in this list, see ccsymbols and cppsymbols. The list is a space-separated list of symbol=value tokens.

cppflags
From ccflags.U:

This variable holds the flags that will be passed to the C pre- processor. It is up to the Makefile to use it.

cpplast
From cppstdin.U:

This variable has the same functionality as cppminus, only it applies to cpprun and not cppstdin.

cppminus
From cppstdin.U:

This variable contains the second part of the string which will invoke the C preprocessor on the standard input and produce to standard output. This variable will have the value - if cppstdin needs a minus to specify standard input, otherwise the value is ``''.

cpprun
From cppstdin.U:

This variable contains the command which will invoke a C preprocessor on standard input and put the output to stdout. It is guaranteed not to be a wrapper and may be a null string if no preprocessor can be made directly available. This preprocessor might be different from the one used by the C compiler. Don't forget to append cpplast after the preprocessor options.

cppstdin
From cppstdin.U:

This variable contains the command which will invoke the C preprocessor on standard input and put the output to stdout. It is primarily used by other Configure units that ask about preprocessor symbols.

cppsymbols
From Cppsym.U:

The variable contains the symbols defined by the C preprocessor alone. The symbols defined by cc or by cc when it calls cpp are not in this list, see ccsymbols and cppccsymbols. The list is a space-separated list of symbol=value tokens.

crosscompile
From crosscompile.U:

This variable conditionally defines the CROSSCOMPILE symbol which signifies that the build process is be a cross-compilation. This is normally set by hints files or from Configure command line.

cryptlib
From d_crypt.U:

This variable holds -lcrypt or the path to a libcrypt.a archive if the crypt() function is not defined in the standard C library. It is up to the Makefile to use this.

csh
From Loc.U:

This variable is used internally by Configure to determine the full pathname (if any) of the csh program. After Configure runs, the value is reset to a plain csh and is not useful.

d

d_access
From d_access.U:

This variable conditionally defines HAS_ACCESS if the access() system call is available to check for access permissions using real IDs.

d_accessx
From d_accessx.U:

This variable conditionally defines the HAS_ACCESSX symbol, which indicates to the C program that the accessx() routine is available.

d_alarm
From d_alarm.U:

This variable conditionally defines the HAS_ALARM symbol, which indicates to the C program that the alarm() routine is available.

d_archlib
From archlib.U:

This variable conditionally defines ARCHLIB to hold the pathname of architecture-dependent library files for $package. If $archlib is the same as $privlib, then this is set to undef.

d_atolf
From atolf.U:

This variable conditionally defines the HAS_ATOLF symbol, which indicates to the C program that the atolf() routine is available.

d_atoll
From atoll.U:

This variable conditionally defines the HAS_ATOLL symbol, which indicates to the C program that the atoll() routine is available.

d_attribut
From d_attribut.U:

This variable conditionally defines HASATTRIBUTE, which indicates the C compiler can check for function attributes, such as printf formats.

d_bcmp
From d_bcmp.U:

This variable conditionally defines the HAS_BCMP symbol if the bcmp() routine is available to compare strings.

d_bcopy
From d_bcopy.U:

This variable conditionally defines the HAS_BCOPY symbol if the bcopy() routine is available to copy strings.

d_bincompat5005
From bincompat5005.U:

This variable conditionally defines BINCOMPAT5005 so that embed.h can take special action if this version of Perl should be binary-compatible with Perl 5.005. This is impossible for builds that use features like threads and multiplicity it is always $undef for those versions.

d_bsd
From Guess.U:

This symbol conditionally defines the symbol BSD when running on a BSD system.

d_bsdgetpgrp
From d_getpgrp.U:

This variable conditionally defines USE_BSD_GETPGRP if getpgrp needs one arguments whereas USG one needs none.

d_bsdsetpgrp
From d_setpgrp.U:

This variable conditionally defines USE_BSD_SETPGRP if setpgrp needs two arguments whereas USG one needs none. See also d_setpgid for a POSIX interface.

d_bzero
From d_bzero.U:

This variable conditionally defines the HAS_BZERO symbol if the bzero() routine is available to set memory to 0.

d_casti32
From d_casti32.U:

This variable conditionally defines CASTI32, which indicates whether the C compiler can cast large floats to 32-bit ints.

d_castneg
From d_castneg.U:

This variable conditionally defines CASTNEG, which indicates wether the C compiler can cast negative float to unsigned.

d_charvspr
From d_vprintf.U:

This variable conditionally defines CHARVSPRINTF if this system has vsprintf returning type (char*). The trend seems to be to declare it as ``int vsprintf()''.

d_chown
From d_chown.U:

This variable conditionally defines the HAS_CHOWN symbol, which indicates to the C program that the chown() routine is available.

d_chroot
From d_chroot.U:

This variable conditionally defines the HAS_CHROOT symbol, which indicates to the C program that the chroot() routine is available.

d_chsize
From d_chsize.U:

This variable conditionally defines the CHSIZE symbol, which indicates to the C program that the chsize() routine is available to truncate files. You might need a -lx to get this routine.

d_closedir
From d_closedir.U:

This variable conditionally defines HAS_CLOSEDIR if closedir() is available.

d_const
From d_const.U:

This variable conditionally defines the HASCONST symbol, which indicates to the C program that this C compiler knows about the const type.

d_crypt
From d_crypt.U:

This variable conditionally defines the CRYPT symbol, which indicates to the C program that the crypt() routine is available to encrypt passwords and the like.

d_csh
From d_csh.U:

This variable conditionally defines the CSH symbol, which indicates to the C program that the C-shell exists.

d_cuserid
From d_cuserid.U:

This variable conditionally defines the HAS_CUSERID symbol, which indicates to the C program that the cuserid() routine is available to get character login names.

d_dbl_dig
From d_dbl_dig.U:

This variable conditionally defines d_dbl_dig if this system's header files provide DBL_DIG, which is the number of significant digits in a double precision number.

d_difftime
From d_difftime.U:

This variable conditionally defines the HAS_DIFFTIME symbol, which indicates to the C program that the difftime() routine is available.

d_dirnamlen
From i_dirent.U:

This variable conditionally defines DIRNAMLEN, which indicates to the C program that the length of directory entry names is provided by a d_namelen field.

d_dlerror
From d_dlerror.U:

This variable conditionally defines the HAS_DLERROR symbol, which indicates to the C program that the dlerror() routine is available.

d_dlopen
From d_dlopen.U:

This variable conditionally defines the HAS_DLOPEN symbol, which indicates to the C program that the dlopen() routine is available.

d_dlsymun
From d_dlsymun.U:

This variable conditionally defines DLSYM_NEEDS_UNDERSCORE, which indicates that we need to prepend an underscore to the symbol name before calling dlsym().

d_dosuid
From d_dosuid.U:

This variable conditionally defines the symbol DOSUID, which tells the C program that it should insert setuid emulation code on hosts which have setuid #! scripts disabled.

d_drand48proto
From d_drand48proto.U:

This variable conditionally defines the HAS_DRAND48_PROTO symbol, which indicates to the C program that the system provides a prototype for the drand48() function. Otherwise, it is up to the program to supply one.

d_dup2
From d_dup2.U:

This variable conditionally defines HAS_DUP2 if dup2() is available to duplicate file descriptors.

d_eaccess
From d_eaccess.U:

This variable conditionally defines the HAS_EACCESS symbol, which indicates to the C program that the eaccess() routine is available.

d_endgrent
From d_endgrent.U:

This variable conditionally defines the HAS_ENDGRENT symbol, which indicates to the C program that the endgrent() routine is available for sequential access of the group database.

d_endhent
From d_endhent.U:

This variable conditionally defines HAS_ENDHOSTENT if endhostent() is available to close whatever was being used for host queries.

d_endnent
From d_endnent.U:

This variable conditionally defines HAS_ENDNETENT if endnetent() is available to close whatever was being used for network queries.

d_endpent
From d_endpent.U:

This variable conditionally defines HAS_ENDPROTOENT if endprotoent() is available to close whatever was being used for protocol queries.

d_endpwent
From d_endpwent.U:

This variable conditionally defines the HAS_ENDPWENT symbol, which indicates to the C program that the endpwent() routine is available for sequential access of the passwd database.

d_endsent
From d_endsent.U:

This variable conditionally defines HAS_ENDSERVENT if endservent() is available to close whatever was being used for service queries.

d_endspent
From d_endspent.U:

This variable conditionally defines HAS_ENDSPENT if endspent() is available to finalize the scan of SysV shadow password entries.

d_eofnblk
From nblock_io.U:

This variable conditionally defines EOF_NONBLOCK if EOF can be seen when reading from a non-blocking I/O source.

d_eunice
From Guess.U:

This variable conditionally defines the symbols EUNICE and VAX, which alerts the C program that it must deal with ideosyncracies of VMS.

d_fchmod
From d_fchmod.U:

This variable conditionally defines the HAS_FCHMOD symbol, which indicates to the C program that the fchmod() routine is available to change mode of opened files.

d_fchown
From d_fchown.U:

This variable conditionally defines the HAS_FCHOWN symbol, which indicates to the C program that the fchown() routine is available to change ownership of opened files.

d_fcntl
From d_fcntl.U:

This variable conditionally defines the HAS_FCNTL symbol, and indicates whether the fcntl() function exists

d_fd_macros
From d_fd_set.U:

This variable contains the eventual value of the HAS_FD_MACROS symbol, which indicates if your C compiler knows about the macros which manipulate an fd_set.

d_fd_set
From d_fd_set.U:

This variable contains the eventual value of the HAS_FD_SET symbol, which indicates if your C compiler knows about the fd_set typedef.

d_fds_bits
From d_fd_set.U:

This variable contains the eventual value of the HAS_FDS_BITS symbol, which indicates if your fd_set typedef contains the fds_bits member. If you have an fd_set typedef, but the dweebs who installed it did a half-fast job and neglected to provide the macros to manipulate an fd_set, HAS_FDS_BITS will let us know how to fix the gaffe.

d_fgetpos
From d_fgetpos.U:

This variable conditionally defines HAS_FGETPOS if fgetpos() is available to get the file position indicator.

d_flexfnam
From d_flexfnam.U:

This variable conditionally defines the FLEXFILENAMES symbol, which indicates that the system supports filenames longer than 14 characters.

d_flock
From d_flock.U:

This variable conditionally defines HAS_FLOCK if flock() is available to do file locking.

d_fork
From d_fork.U:

This variable conditionally defines the HAS_FORK symbol, which indicates to the C program that the fork() routine is available.

d_fpathconf
From d_pathconf.U:

This variable conditionally defines the HAS_FPATHCONF symbol, which indicates to the C program that the pathconf() routine is available to determine file-system related limits and options associated with a given open file descriptor.

d_fpos64_t
From d_fpos64_t.U:

This symbol will be defined if the C compiler supports fpos64_t.

d_fs_data_s
From d_fs_data_s.U:

This variable conditionally defines the HAS_STRUCT_FS_DATA symbol, which indicates that the struct fs_data is supported.

d_fseeko
From d_fseeko.U:

This variable conditionally defines the HAS_FSEEKO symbol, which indicates to the C program that the fseeko() routine is available.

d_fsetpos
From d_fsetpos.U:

This variable conditionally defines HAS_FSETPOS if fsetpos() is available to set the file position indicator.

d_fstatfs
From d_fstatfs.U:

This variable conditionally defines the HAS_FSTATFS symbol, which indicates to the C program that the fstatfs() routine is available.

d_fstatvfs
From d_statvfs.U:

This variable conditionally defines the HAS_FSTATVFS symbol, which indicates to the C program that the fstatvfs() routine is available.

d_ftello
From d_ftello.U:

This variable conditionally defines the HAS_FTELLO symbol, which indicates to the C program that the ftello() routine is available.

d_ftime
From d_ftime.U:

This variable conditionally defines the HAS_FTIME symbol, which indicates that the ftime() routine exists. The ftime() routine is basically a sub-second accuracy clock.

d_Gconvert
From d_gconvert.U:

This variable holds what Gconvert is defined as to convert floating point numbers into strings. It could be gconvert or a more complex macro emulating gconvert with gcvt() or sprintf. Possible values are: d_Gconvert=gconvert((x),(n),(t),(b)) d_Gconvert=gcvt((x),(n),(b)) d_Gconvert=sprintf((b),%.*g,(n),(x))

d_getcwd
From d_getcwd.U:

This variable conditionally defines the HAS_GETCWD symbol, which indicates to the C program that the getcwd() routine is available to get the current working directory.

d_getfsstat
From d_getfsstat.U:

This variable conditionally defines the HAS_GETFSSTAT symbol, which indicates to the C program that the getfsstat() routine is available.

d_getgrent
From d_getgrent.U:

This variable conditionally defines the HAS_GETGRENT symbol, which indicates to the C program that the getgrent() routine is available for sequential access of the group database.

d_getgrps
From d_getgrps.U:

This variable conditionally defines the HAS_GETGROUPS symbol, which indicates to the C program that the getgroups() routine is available to get the list of process groups.

d_gethbyaddr
From d_gethbyad.U:

This variable conditionally defines the HAS_GETHOSTBYADDR symbol, which indicates to the C program that the gethostbyaddr() routine is available to look up hosts by their IP addresses.

d_gethbyname
From d_gethbynm.U:

This variable conditionally defines the HAS_GETHOSTBYNAME symbol, which indicates to the C program that the gethostbyname() routine is available to look up host names in some data base or other.

d_gethent
From d_gethent.U:

This variable conditionally defines HAS_GETHOSTENT if gethostent() is available to look up host names in some data base or another.

d_gethname
From d_gethname.U:

This variable conditionally defines the HAS_GETHOSTNAME symbol, which indicates to the C program that the gethostname() routine may be used to derive the host name.

d_gethostprotos
From d_gethostprotos.U:

This variable conditionally defines the HAS_GETHOST_PROTOS symbol, which indicates to the C program that <netdb.h> supplies prototypes for the various gethost*() functions. See also netdbtype.U for probing for various netdb types.

d_getlogin
From d_getlogin.U:

This variable conditionally defines the HAS_GETLOGIN symbol, which indicates to the C program that the getlogin() routine is available to get the login name.

d_getmnt
From d_getmnt.U:

This variable conditionally defines the HAS_GETMNT symbol, which indicates to the C program that the getmnt() routine is available to retrieve one or more mount info blocks by filename.

d_getmntent
From d_getmntent.U:

This variable conditionally defines the HAS_GETMNTENT symbol, which indicates to the C program that the getmntent() routine is available to iterate through mounted files to get their mount info.

d_getnbyaddr
From d_getnbyad.U:

This variable conditionally defines the HAS_GETNETBYADDR symbol, which indicates to the C program that the getnetbyaddr() routine is available to look up networks by their IP addresses.

d_getnbyname
From d_getnbynm.U:

This variable conditionally defines the HAS_GETNETBYNAME symbol, which indicates to the C program that the getnetbyname() routine is available to look up networks by their names.

d_getnent
From d_getnent.U:

This variable conditionally defines HAS_GETNETENT if getnetent() is available to look up network names in some data base or another.

d_getnetprotos
From d_getnetprotos.U:

This variable conditionally defines the HAS_GETNET_PROTOS symbol, which indicates to the C program that <netdb.h> supplies prototypes for the various getnet*() functions. See also netdbtype.U for probing for various netdb types.

d_getpbyname
From d_getprotby.U:

This variable conditionally defines the HAS_GETPROTOBYNAME symbol, which indicates to the C program that the getprotobyname() routine is available to look up protocols by their name.

d_getpbynumber
From d_getprotby.U:

This variable conditionally defines the HAS_GETPROTOBYNUMBER symbol, which indicates to the C program that the getprotobynumber() routine is available to look up protocols by their number.

d_getpent
From d_getpent.U:

This variable conditionally defines HAS_GETPROTOENT if getprotoent() is available to look up protocols in some data base or another.

d_getpgid
From d_getpgid.U:

This variable conditionally defines the HAS_GETPGID symbol, which indicates to the C program that the getpgid(pid) function is available to get the process group id.

d_getpgrp2
From d_getpgrp2.U:

This variable conditionally defines the HAS_GETPGRP2 symbol, which indicates to the C program that the getpgrp2() (as in DG/UX) routine is available to get the current process group.

d_getpgrp
From d_getpgrp.U:

This variable conditionally defines HAS_GETPGRP if getpgrp() is available to get the current process group.

d_getppid
From d_getppid.U:

This variable conditionally defines the HAS_GETPPID symbol, which indicates to the C program that the getppid() routine is available to get the parent process ID.

d_getprior
From d_getprior.U:

This variable conditionally defines HAS_GETPRIORITY if getpriority() is available to get a process's priority.

d_getprotoprotos
From d_getprotoprotos.U:

This variable conditionally defines the HAS_GETPROTO_PROTOS symbol, which indicates to the C program that <netdb.h> supplies prototypes for the various getproto*() functions. See also netdbtype.U for probing for various netdb types.

d_getpwent
From d_getpwent.U:

This variable conditionally defines the HAS_GETPWENT symbol, which indicates to the C program that the getpwent() routine is available for sequential access of the passwd database.

d_getsbyname
From d_getsrvby.U:

This variable conditionally defines the HAS_GETSERVBYNAME symbol, which indicates to the C program that the getservbyname() routine is available to look up services by their name.

d_getsbyport
From d_getsrvby.U:

This variable conditionally defines the HAS_GETSERVBYPORT symbol, which indicates to the C program that the getservbyport() routine is available to look up services by their port.

d_getsent
From d_getsent.U:

This variable conditionally defines HAS_GETSERVENT if getservent() is available to look up network services in some data base or another.

d_getservprotos
From d_getservprotos.U:

This variable conditionally defines the HAS_GETSERV_PROTOS symbol, which indicates to the C program that <netdb.h> supplies prototypes for the various getserv*() functions. See also netdbtype.U for probing for various netdb types.

d_getspent
From d_getspent.U:

This variable conditionally defines HAS_GETSPENT if getspent() is available to retrieve SysV shadow password entries sequentially.

d_getspnam
From d_getspnam.U:

This variable conditionally defines HAS_GETSPNAM if getspnam() is available to retrieve SysV shadow password entries by name.

d_gettimeod
From d_ftime.U:

This variable conditionally defines the HAS_GETTIMEOFDAY symbol, which indicates that the gettimeofday() system call exists (to obtain a sub-second accuracy clock). You should probably include <sys/resource.h>.

d_gnulibc
From d_gnulibc.U:

Defined if we're dealing with the GNU C Library.

d_grpasswd
From i_grp.U:

This variable conditionally defines GRPASSWD, which indicates that struct group in <grp.h> contains gr_passwd.

d_hasmntopt
From d_hasmntopt.U:

This variable conditionally defines the HAS_HASMNTOPT symbol, which indicates to the C program that the hasmntopt() routine is available to query the mount options of file systems.

d_htonl
From d_htonl.U:

This variable conditionally defines HAS_HTONL if htonl() and its friends are available to do network order byte swapping.

d_iconv
From d_iconv.U:

This variable conditionally defines the HAS_ICONV symbol, which indicates to the C program that the iconv() routine is available.

d_index
From d_strchr.U:

This variable conditionally defines HAS_INDEX if index() and rindex() are available for string searching.

d_inetaton
From d_inetaton.U:

This variable conditionally defines the HAS_INET_ATON symbol, which indicates to the C program that the inet_aton() function is available to parse IP address dotted-quad strings.

d_int64_t
From d_int64_t.U:

This symbol will be defined if the C compiler supports int64_t.

d_isascii
From d_isascii.U:

This variable conditionally defines the HAS_ISASCII constant, which indicates to the C program that isascii() is available.

d_killpg
From d_killpg.U:

This variable conditionally defines the HAS_KILLPG symbol, which indicates to the C program that the killpg() routine is available to kill process groups.

d_lchown
From d_lchown.U:

This variable conditionally defines the HAS_LCHOWN symbol, which indicates to the C program that the lchown() routine is available to operate on a symbolic link (instead of following the link).

d_ldbl_dig
From d_ldbl_dig.U:

This variable conditionally defines d_ldbl_dig if this system's header files provide LDBL_DIG, which is the number of significant digits in a long double precision number.

d_link
From d_link.U:

This variable conditionally defines HAS_LINK if link() is available to create hard links.

d_locconv
From d_locconv.U:

This variable conditionally defines HAS_LOCALECONV if localeconv() is available for numeric and monetary formatting conventions.

d_lockf
From d_lockf.U:

This variable conditionally defines HAS_LOCKF if lockf() is available to do file locking.

d_longdbl
From d_longdbl.U:

This variable conditionally defines HAS_LONG_DOUBLE if the long double type is supported.

d_longlong
From d_longlong.U:

This variable conditionally defines HAS_LONG_LONG if the long long type is supported.

d_lseekproto
From d_lseekproto.U:

This variable conditionally defines the HAS_LSEEK_PROTO symbol, which indicates to the C program that the system provides a prototype for the lseek() function. Otherwise, it is up to the program to supply one.

d_lstat
From d_lstat.U:

This variable conditionally defines HAS_LSTAT if lstat() is available to do file stats on symbolic links.

d_madvise
From d_madvise.U:

This variable conditionally defines HAS_MADVISE if madvise() is available to map a file into memory.

d_mblen
From d_mblen.U:

This variable conditionally defines the HAS_MBLEN symbol, which indicates to the C program that the mblen() routine is available to find the number of bytes in a multibye character.

d_mbstowcs
From d_mbstowcs.U:

This variable conditionally defines the HAS_MBSTOWCS symbol, which indicates to the C program that the mbstowcs() routine is available to convert a multibyte string into a wide character string.

d_mbtowc
From d_mbtowc.U:

This variable conditionally defines the HAS_MBTOWC symbol, which indicates to the C program that the mbtowc() routine is available to convert multibyte to a wide character.

d_memchr
From d_memchr.U:

This variable conditionally defines the HAS_MEMCHR symbol, which indicates to the C program that the memchr() routine is available to locate characters within a C string.

d_memcmp
From d_memcmp.U:

This variable conditionally defines the HAS_MEMCMP symbol, which indicates to the C program that the memcmp() routine is available to compare blocks of memory.

d_memcpy
From d_memcpy.U:

This variable conditionally defines the HAS_MEMCPY symbol, which indicates to the C program that the memcpy() routine is available to copy blocks of memory.

d_memmove
From d_memmove.U:

This variable conditionally defines the HAS_MEMMOVE symbol, which indicates to the C program that the memmove() routine is available to copy potentatially overlapping blocks of memory.

d_memset
From d_memset.U:

This variable conditionally defines the HAS_MEMSET symbol, which indicates to the C program that the memset() routine is available to set blocks of memory.

d_mkdir
From d_mkdir.U:

This variable conditionally defines the HAS_MKDIR symbol, which indicates to the C program that the mkdir() routine is available to create directories..

d_mkdtemp
From d_mkdtemp.U:

This variable conditionally defines the HAS_MKDTEMP symbol, which indicates to the C program that the mkdtemp() routine is available to exclusively create a uniquely named temporary directory.

d_mkfifo
From d_mkfifo.U:

This variable conditionally defines the HAS_MKFIFO symbol, which indicates to the C program that the mkfifo() routine is available.

d_mkstemp
From d_mkstemp.U:

This variable conditionally defines the HAS_MKSTEMP symbol, which indicates to the C program that the mkstemp() routine is available to exclusively create and open a uniquely named temporary file.

d_mkstemps
From d_mkstemps.U:

This variable conditionally defines the HAS_MKSTEMPS symbol, which indicates to the C program that the mkstemps() routine is available to exclusively create and open a uniquely named (with a suffix) temporary file.

d_mktime
From d_mktime.U:

This variable conditionally defines the HAS_MKTIME symbol, which indicates to the C program that the mktime() routine is available.

d_mmap
From d_mmap.U:

This variable conditionally defines HAS_MMAP if mmap() is available to map a file into memory.

d_mprotect
From d_mprotect.U:

This variable conditionally defines HAS_MPROTECT if mprotect() is available to modify the access protection of a memory mapped file.

d_msg
From d_msg.U:

This variable conditionally defines the HAS_MSG symbol, which indicates that the entire msg*(2) library is present.

d_msg_ctrunc
From d_socket.U:

This variable conditionally defines the HAS_MSG_CTRUNC symbol, which indicates that the MSG_CTRUNC is available. #ifdef is not enough because it may be an enum, glibc has been known to do this.

d_msg_dontroute
From d_socket.U:

This variable conditionally defines the HAS_MSG_DONTROUTE symbol, which indicates that the MSG_DONTROUTE is available. #ifdef is not enough because it may be an enum, glibc has been known to do this.

d_msg_oob
From d_socket.U:

This variable conditionally defines the HAS_MSG_OOB symbol, which indicates that the MSG_OOB is available. #ifdef is not enough because it may be an enum, glibc has been known to do this.

d_msg_peek
From d_socket.U:

This variable conditionally defines the HAS_MSG_PEEK symbol, which indicates that the MSG_PEEK is available. #ifdef is not enough because it may be an enum, glibc has been known to do this.

d_msg_proxy
From d_socket.U:

This variable conditionally defines the HAS_MSG_PROXY symbol, which indicates that the MSG_PROXY is available. #ifdef is not enough because it may be an enum, glibc has been known to do this.

d_msgctl
From d_msgctl.U:

This variable conditionally defines the HAS_MSGCTL symbol, which indicates to the C program that the msgctl() routine is available.

d_msgget
From d_msgget.U:

This variable conditionally defines the HAS_MSGGET symbol, which indicates to the C program that the msgget() routine is available.

d_msgrcv
From d_msgrcv.U:

This variable conditionally defines the HAS_MSGRCV symbol, which indicates to the C program that the msgrcv() routine is available.

d_msgsnd
From d_msgsnd.U:

This variable conditionally defines the HAS_MSGSND symbol, which indicates to the C program that the msgsnd() routine is available.

d_msync
From d_msync.U:

This variable conditionally defines HAS_MSYNC if msync() is available to synchronize a mapped file.

d_munmap
From d_munmap.U:

This variable conditionally defines HAS_MUNMAP if munmap() is available to unmap a region mapped by mmap().

d_mymalloc
From mallocsrc.U:

This variable conditionally defines MYMALLOC in case other parts of the source want to take special action if MYMALLOC is used. This may include different sorts of profiling or error detection.

d_nice
From d_nice.U:

This variable conditionally defines the HAS_NICE symbol, which indicates to the C program that the nice() routine is available.

d_nv_preserves_uv
From perlxv.U:

This variable indicates whether a variable of type nvtype can preserve all the bits a variable of type uvtype.

d_off64_t
From d_off64_t.U:

This symbol will be defined if the C compiler supports off64_t.

d_old_pthread_create_joinable
From d_pthrattrj.U:

This variable conditionally defines pthread_create_joinable. undef if pthread.h defines PTHREAD_CREATE_JOINABLE.

d_oldpthreads
From usethreads.U:

This variable conditionally defines the OLD_PTHREADS_API symbol, and indicates that Perl should be built to use the old draft POSIX threads API. This is only potentially meaningful if usethreads is set.

d_oldsock
From d_socket.U:

This variable conditionally defines the OLDSOCKET symbol, which indicates that the BSD socket interface is based on 4.1c and not 4.2.

d_open3
From d_open3.U:

This variable conditionally defines the HAS_OPEN3 manifest constant, which indicates to the C program that the 3 argument version of the open(2) function is available.

d_pathconf
From d_pathconf.U:

This variable conditionally defines the HAS_PATHCONF symbol, which indicates to the C program that the pathconf() routine is available to determine file-system related limits and options associated with a given filename.

d_pause
From d_pause.U:

This variable conditionally defines the HAS_PAUSE symbol, which indicates to the C program that the pause() routine is available to suspend a process until a signal is received.

d_phostname
From d_gethname.U:

This variable conditionally defines the HAS_PHOSTNAME symbol, which contains the shell command which, when fed to popen(), may be used to derive the host name.

d_pipe
From d_pipe.U:

This variable conditionally defines the HAS_PIPE symbol, which indicates to the C program that the pipe() routine is available to create an inter-process channel.

d_poll
From d_poll.U:

This variable conditionally defines the HAS_POLL symbol, which indicates to the C program that the poll() routine is available to poll active file descriptors.

d_portable
From d_portable.U:

This variable conditionally defines the PORTABLE symbol, which indicates to the C program that it should not assume that it is running on the machine it was compiled on.

d_PRId64
From quadfio.U:

This variable conditionally defines the PERL_PRId64 symbol, which indiciates that stdio has a symbol to print 64-bit decimal numbers.

d_PRIeldbl
From longdblfio.U:

This variable conditionally defines the PERL_PRIfldlbl symbol, which indiciates that stdio has a symbol to print long doubles.

d_PRIEldbl
From longdblfio.U:

This variable conditionally defines the PERL_PRIfldlbl symbol, which indiciates that stdio has a symbol to print long doubles.

d_PRIfldbl
From longdblfio.U:

This variable conditionally defines the PERL_PRIfldlbl symbol, which indiciates that stdio has a symbol to print long doubles.

d_PRIFldbl
From longdblfio.U:

This variable conditionally defines the PERL_PRIfldlbl symbol, which indiciates that stdio has a symbol to print long doubles.

d_PRIgldbl
From longdblfio.U:

This variable conditionally defines the PERL_PRIfldlbl symbol, which indiciates that stdio has a symbol to print long doubles.

d_PRIGldbl
From longdblfio.U:

This variable conditionally defines the PERL_PRIfldlbl symbol, which indiciates that stdio has a symbol to print long doubles.

d_PRIi64
From quadfio.U:

This variable conditionally defines the PERL_PRIi64 symbol, which indiciates that stdio has a symbol to print 64-bit decimal numbers.

d_PRIo64
From quadfio.U:

This variable conditionally defines the PERL_PRIo64 symbol, which indiciates that stdio has a symbol to print 64-bit octal numbers.

d_PRIu64
From quadfio.U:

This variable conditionally defines the PERL_PRIu64 symbol, which indiciates that stdio has a symbol to print 64-bit unsigned decimal numbers.

d_PRIx64
From quadfio.U:

This variable conditionally defines the PERL_PRIx64 symbol, which indiciates that stdio has a symbol to print 64-bit hexadecimal numbers.

d_PRIX64
From quadfio.U:

This variable conditionally defines the PERL_PRIX64 symbol, which indiciates that stdio has a symbol to print 64-bit hExADECimAl numbers.

d_pthread_yield
From d_pthread_y.U:

This variable conditionally defines the HAS_PTHREAD_YIELD symbol if the pthread_yield routine is available to yield the execution of the current thread.

d_pwage
From i_pwd.U:

This variable conditionally defines PWAGE, which indicates that struct passwd contains pw_age.

d_pwchange
From i_pwd.U:

This variable conditionally defines PWCHANGE, which indicates that struct passwd contains pw_change.

d_pwclass
From i_pwd.U:

This variable conditionally defines PWCLASS, which indicates that struct passwd contains pw_class.

d_pwcomment
From i_pwd.U:

This variable conditionally defines PWCOMMENT, which indicates that struct passwd contains pw_comment.

d_pwexpire
From i_pwd.U:

This variable conditionally defines PWEXPIRE, which indicates that struct passwd contains pw_expire.

d_pwgecos
From i_pwd.U:

This variable conditionally defines PWGECOS, which indicates that struct passwd contains pw_gecos.

d_pwpasswd
From i_pwd.U:

This variable conditionally defines PWPASSWD, which indicates that struct passwd contains pw_passwd.

d_pwquota
From i_pwd.U:

This variable conditionally defines PWQUOTA, which indicates that struct passwd contains pw_quota.

d_qgcvt
From d_qgcvt.U:

This variable conditionally defines the HAS_QGCVT symbol, which indicates to the C program that the qgcvt() routine is available.

d_quad
From quadtype.U:

This variable, if defined, tells that there's a 64-bit integer type, quadtype.

d_readdir
From d_readdir.U:

This variable conditionally defines HAS_READDIR if readdir() is available to read directory entries.

d_readlink
From d_readlink.U:

This variable conditionally defines the HAS_READLINK symbol, which indicates to the C program that the readlink() routine is available to read the value of a symbolic link.

d_rename
From d_rename.U:

This variable conditionally defines the HAS_RENAME symbol, which indicates to the C program that the rename() routine is available to rename files.

d_rewinddir
From d_readdir.U:

This variable conditionally defines HAS_REWINDDIR if rewinddir() is available.

d_rmdir
From d_rmdir.U:

This variable conditionally defines HAS_RMDIR if rmdir() is available to remove directories.

d_safebcpy
From d_safebcpy.U:

This variable conditionally defines the HAS_SAFE_BCOPY symbol if the bcopy() routine can do overlapping copies.

d_safemcpy
From d_safemcpy.U:

This variable conditionally defines the HAS_SAFE_MEMCPY symbol if the memcpy() routine can do overlapping copies.

d_sanemcmp
From d_sanemcmp.U:

This variable conditionally defines the HAS_SANE_MEMCMP symbol if the memcpy() routine is available and can be used to compare relative magnitudes of chars with their high bits set.

d_sched_yield
From d_pthread_y.U:

This variable conditionally defines the HAS_SCHED_YIELD symbol if the sched_yield routine is available to yield the execution of the current thread.

d_scm_rights
From d_socket.U:

This variable conditionally defines the HAS_SCM_RIGHTS symbol, which indicates that the SCM_RIGHTS is available. #ifdef is not enough because it may be an enum, glibc has been known to do this.

d_seekdir
From d_readdir.U:

This variable conditionally defines HAS_SEEKDIR if seekdir() is available.

d_select
From d_select.U:

This variable conditionally defines HAS_SELECT if select() is available to select active file descriptors. A <sys/time.h> inclusion may be necessary for the timeout field.

d_sem
From d_sem.U:

This variable conditionally defines the HAS_SEM symbol, which indicates that the entire sem*(2) library is present.

d_semctl
From d_semctl.U:

This variable conditionally defines the HAS_SEMCTL symbol, which indicates to the C program that the semctl() routine is available.

d_semctl_semid_ds
From d_union_semun.U:

This variable conditionally defines USE_SEMCTL_SEMID_DS, which indicates that struct semid_ds * is to be used for semctl IPC_STAT.

d_semctl_semun
From d_union_semun.U:

This variable conditionally defines USE_SEMCTL_SEMUN, which indicates that union semun is to be used for semctl IPC_STAT.

d_semget
From d_semget.U:

This variable conditionally defines the HAS_SEMGET symbol, which indicates to the C program that the semget() routine is available.

d_semop
From d_semop.U:

This variable conditionally defines the HAS_SEMOP symbol, which indicates to the C program that the semop() routine is available.

d_setegid
From d_setegid.U:

This variable conditionally defines the HAS_SETEGID symbol, which indicates to the C program that the setegid() routine is available to change the effective gid of the current program.

d_seteuid
From d_seteuid.U:

This variable conditionally defines the HAS_SETEUID symbol, which indicates to the C program that the seteuid() routine is available to change the effective uid of the current program.

d_setgrent
From d_setgrent.U:

This variable conditionally defines the HAS_SETGRENT symbol, which indicates to the C program that the setgrent() routine is available for initializing sequential access to the group database.

d_setgrps
From d_setgrps.U:

This variable conditionally defines the HAS_SETGROUPS symbol, which indicates to the C program that the setgroups() routine is available to set the list of process groups.

d_sethent
From d_sethent.U:

This variable conditionally defines HAS_SETHOSTENT if sethostent() is available.

d_setlinebuf
From d_setlnbuf.U:

This variable conditionally defines the HAS_SETLINEBUF symbol, which indicates to the C program that the setlinebuf() routine is available to change stderr or stdout from block-buffered or unbuffered to a line-buffered mode.

d_setlocale
From d_setlocale.U:

This variable conditionally defines HAS_SETLOCALE if setlocale() is available to handle locale-specific ctype implementations.

d_setnent
From d_setnent.U:

This variable conditionally defines HAS_SETNETENT if setnetent() is available.

d_setpent
From d_setpent.U:

This variable conditionally defines HAS_SETPROTOENT if setprotoent() is available.

d_setpgid
From d_setpgid.U:

This variable conditionally defines the HAS_SETPGID symbol if the setpgid(pid, gpid) function is available to set process group ID.

d_setpgrp2
From d_setpgrp2.U:

This variable conditionally defines the HAS_SETPGRP2 symbol, which indicates to the C program that the setpgrp2() (as in DG/UX) routine is available to set the current process group.

d_setpgrp
From d_setpgrp.U:

This variable conditionally defines HAS_SETPGRP if setpgrp() is available to set the current process group.

d_setprior
From d_setprior.U:

This variable conditionally defines HAS_SETPRIORITY if setpriority() is available to set a process's priority.

d_setpwent
From d_setpwent.U:

This variable conditionally defines the HAS_SETPWENT symbol, which indicates to the C program that the setpwent() routine is available for initializing sequential access to the passwd database.

d_setregid
From d_setregid.U:

This variable conditionally defines HAS_SETREGID if setregid() is available to change the real and effective gid of the current process.

d_setresgid
From d_setregid.U:

This variable conditionally defines HAS_SETRESGID if setresgid() is available to change the real, effective and saved gid of the current process.

d_setresuid
From d_setreuid.U:

This variable conditionally defines HAS_SETREUID if setresuid() is available to change the real, effective and saved uid of the current process.

d_setreuid
From d_setreuid.U:

This variable conditionally defines HAS_SETREUID if setreuid() is available to change the real and effective uid of the current process.

d_setrgid
From d_setrgid.U:

This variable conditionally defines the HAS_SETRGID symbol, which indicates to the C program that the setrgid() routine is available to change the real gid of the current program.

d_setruid
From d_setruid.U:

This variable conditionally defines the HAS_SETRUID symbol, which indicates to the C program that the setruid() routine is available to change the real uid of the current program.

d_setsent
From d_setsent.U:

This variable conditionally defines HAS_SETSERVENT if setservent() is available.

d_setsid
From d_setsid.U:

This variable conditionally defines HAS_SETSID if setsid() is available to set the process group ID.

d_setspent
From d_setspent.U:

This variable conditionally defines HAS_SETSPENT if setspent() is available to initialize the scan of SysV shadow password entries.

d_setvbuf
From d_setvbuf.U:

This variable conditionally defines the HAS_SETVBUF symbol, which indicates to the C program that the setvbuf() routine is available to change buffering on an open stdio stream.

d_sfio
From d_sfio.U:

This variable conditionally defines the USE_SFIO symbol, and indicates whether sfio is available (and should be used).

d_shm
From d_shm.U:

This variable conditionally defines the HAS_SHM symbol, which indicates that the entire shm*(2) library is present.

d_shmat
From d_shmat.U:

This variable conditionally defines the HAS_SHMAT symbol, which indicates to the C program that the shmat() routine is available.

d_shmatprototype
From d_shmat.U:

This variable conditionally defines the HAS_SHMAT_PROTOTYPE symbol, which indicates that sys/shm.h has a prototype for shmat.

d_shmctl
From d_shmctl.U:

This variable conditionally defines the HAS_SHMCTL symbol, which indicates to the C program that the shmctl() routine is available.

d_shmdt
From d_shmdt.U:

This variable conditionally defines the HAS_SHMDT symbol, which indicates to the C program that the shmdt() routine is available.

d_shmget
From d_shmget.U:

This variable conditionally defines the HAS_SHMGET symbol, which indicates to the C program that the shmget() routine is available.

d_sigaction
From d_sigaction.U:

This variable conditionally defines the HAS_SIGACTION symbol, which indicates that the Vr4 sigaction() routine is available.

d_sigsetjmp
From d_sigsetjmp.U:

This variable conditionally defines the HAS_SIGSETJMP symbol, which indicates that the sigsetjmp() routine is available to call setjmp() and optionally save the process's signal mask.

d_socket
From d_socket.U:

This variable conditionally defines HAS_SOCKET, which indicates that the BSD socket interface is supported.

d_socklen_t
From d_socklen_t.U:

This symbol will be defined if the C compiler supports socklen_t.

d_sockpair
From d_socket.U:

This variable conditionally defines the HAS_SOCKETPAIR symbol, which indicates that the BSD socketpair() is supported.

d_sqrtl
From d_sqrtl.U:

This variable conditionally defines the HAS_SQRTL symbol, which indicates to the C program that the sqrtl() routine is available.

d_statblks
From d_statblks.U:

This variable conditionally defines USE_STAT_BLOCKS if this system has a stat structure declaring st_blksize and st_blocks.

d_statfs_f_flags
From d_statfs_f_flags.U:

This variable conditionally defines the HAS_STRUCT_STATFS_F_FLAGS symbol, which indicates to struct statfs from has f_flags member. This kind of struct statfs is coming from sys/mount.h (BSD), not from sys/statfs.h (SYSV).

d_statfs_s
From d_statfs_s.U:

This variable conditionally defines the HAS_STRUCT_STATFS symbol, which indicates that the struct statfs is supported.

d_statvfs
From d_statvfs.U:

This variable conditionally defines the HAS_STATVFS symbol, which indicates to the C program that the statvfs() routine is available.

d_stdio_cnt_lval
From d_stdstdio.U:

This variable conditionally defines STDIO_CNT_LVALUE if the FILE_cnt macro can be used as an lvalue.

d_stdio_ptr_lval
From d_stdstdio.U:

This variable conditionally defines STDIO_PTR_LVALUE if the FILE_ptr macro can be used as an lvalue.

d_stdio_stream_array
From stdio_streams.U:

This variable tells whether there is an array holding the stdio streams.

d_stdiobase
From d_stdstdio.U:

This variable conditionally defines USE_STDIO_BASE if this system has a FILE structure declaring a usable _base field (or equivalent) in stdio.h.

d_stdstdio
From d_stdstdio.U:

This variable conditionally defines USE_STDIO_PTR if this system has a FILE structure declaring usable _ptr and _cnt fields (or equivalent) in stdio.h.

d_strchr
From d_strchr.U:

This variable conditionally defines HAS_STRCHR if strchr() and strrchr() are available for string searching.

d_strcoll
From d_strcoll.U:

This variable conditionally defines HAS_STRCOLL if strcoll() is available to compare strings using collating information.

d_strctcpy
From d_strctcpy.U:

This variable conditionally defines the USE_STRUCT_COPY symbol, which indicates to the C program that this C compiler knows how to copy structures.

d_strerrm
From d_strerror.U:

This variable holds what Strerrr is defined as to translate an error code condition into an error message string. It could be strerror or a more complex macro emulating strrror with sys_errlist[], or the unknown string when both strerror and sys_errlist are missing.

d_strerror
From d_strerror.U:

This variable conditionally defines HAS_STRERROR if strerror() is available to translate error numbers to strings.

d_strtod
From d_strtod.U:

This variable conditionally defines the HAS_STRTOD symbol, which indicates to the C program that the strtod() routine is available to provide better numeric string conversion than atof().

d_strtol
From d_strtol.U:

This variable conditionally defines the HAS_STRTOL symbol, which indicates to the C program that the strtol() routine is available to provide better numeric string conversion than atoi() and friends.

d_strtold
From d_strtold.U:

This variable conditionally defines the HAS_STRTOLD symbol, which indicates to the C program that the strtold() routine is available.

d_strtoll
From d_strtoll.U:

This variable conditionally defines the HAS_STRTOLL symbol, which indicates to the C program that the strtoll() routine is available.

d_strtoul
From d_strtoul.U:

This variable conditionally defines the HAS_STRTOUL symbol, which indicates to the C program that the strtoul() routine is available to provide conversion of strings to unsigned long.

d_strtoull
From d_strtoull.U:

This variable conditionally defines the HAS_STRTOULL symbol, which indicates to the C program that the strtoull() routine is available.

d_strtouq
From d_strtouq.U:

This variable conditionally defines the HAS_STRTOUQ symbol, which indicates to the C program that the strtouq() routine is available.

d_strxfrm
From d_strxfrm.U:

This variable conditionally defines HAS_STRXFRM if strxfrm() is available to transform strings.

d_suidsafe
From d_dosuid.U:

This variable conditionally defines SETUID_SCRIPTS_ARE_SECURE_NOW if setuid scripts can be secure. This test looks in /dev/fd/.

d_symlink
From d_symlink.U:

This variable conditionally defines the HAS_SYMLINK symbol, which indicates to the C program that the symlink() routine is available to create symbolic links.

d_syscall
From d_syscall.U:

This variable conditionally defines HAS_SYSCALL if syscall() is available call arbitrary system calls.

d_sysconf
From d_sysconf.U:

This variable conditionally defines the HAS_SYSCONF symbol, which indicates to the C program that the sysconf() routine is available to determine system related limits and options.

d_sysernlst
From d_strerror.U:

This variable conditionally defines HAS_SYS_ERRNOLIST if sys_errnolist[] is available to translate error numbers to the symbolic name.

d_syserrlst
From d_strerror.U:

This variable conditionally defines HAS_SYS_ERRLIST if sys_errlist[] is available to translate error numbers to strings.

d_system
From d_system.U:

This variable conditionally defines HAS_SYSTEM if system() is available to issue a shell command.

d_tcgetpgrp
From d_tcgtpgrp.U:

This variable conditionally defines the HAS_TCGETPGRP symbol, which indicates to the C program that the tcgetpgrp() routine is available. to get foreground process group ID.

d_tcsetpgrp
From d_tcstpgrp.U:

This variable conditionally defines the HAS_TCSETPGRP symbol, which indicates to the C program that the tcsetpgrp() routine is available to set foreground process group ID.

d_telldir
From d_readdir.U:

This variable conditionally defines HAS_TELLDIR if telldir() is available.

d_telldirproto
From d_telldirproto.U:

This variable conditionally defines the HAS_TELLDIR_PROTO symbol, which indicates to the C program that the system provides a prototype for the telldir() function. Otherwise, it is up to the program to supply one.

d_time
From d_time.U:

This variable conditionally defines the HAS_TIME symbol, which indicates that the time() routine exists. The time() routine is normaly provided on UNIX systems.

d_times
From d_times.U:

This variable conditionally defines the HAS_TIMES symbol, which indicates that the times() routine exists. The times() routine is normaly provided on UNIX systems. You may have to include <sys/times.h>.

d_truncate
From d_truncate.U:

This variable conditionally defines HAS_TRUNCATE if truncate() is available to truncate files.

d_tzname
From d_tzname.U:

This variable conditionally defines HAS_TZNAME if tzname[] is available to access timezone names.

d_umask
From d_umask.U:

This variable conditionally defines the HAS_UMASK symbol, which indicates to the C program that the umask() routine is available. to set and get the value of the file creation mask.

d_uname
From d_gethname.U:

This variable conditionally defines the HAS_UNAME symbol, which indicates to the C program that the uname() routine may be used to derive the host name.

d_union_semun
From d_union_semun.U:

This variable conditionally defines HAS_UNION_SEMUN if the union semun is defined by including <sys/sem.h>.

d_ustat
From d_ustat.U:

This variable conditionally defines HAS_USTAT if ustat() is available to query file system statistics by dev_t.

d_vendorarch
From vendorarch.U:

This variable conditionally defined PERL_VENDORARCH.

d_vendorbin
From vendorbin.U:

This variable conditionally defines PERL_VENDORBIN.

d_vendorlib
From vendorlib.U:

This variable conditionally defines PERL_VENDORLIB.

d_vfork
From d_vfork.U:

This variable conditionally defines the HAS_VFORK symbol, which indicates the vfork() routine is available.

d_void_closedir
From d_closedir.U:

This variable conditionally defines VOID_CLOSEDIR if closedir() does not return a value.

d_voidsig
From d_voidsig.U:

This variable conditionally defines VOIDSIG if this system declares ``void (*signal(...))()'' in signal.h. The old way was to declare it as ``int (*signal(...))()''.

d_voidtty
From i_sysioctl.U:

This variable conditionally defines USE_IOCNOTTY to indicate that the ioctl() call with TIOCNOTTY should be used to void tty association. Otherwise (on USG probably), it is enough to close the standard file decriptors and do a setpgrp().

d_volatile
From d_volatile.U:

This variable conditionally defines the HASVOLATILE symbol, which indicates to the C program that this C compiler knows about the volatile declaration.

d_vprintf
From d_vprintf.U:

This variable conditionally defines the HAS_VPRINTF symbol, which indicates to the C program that the vprintf() routine is available to printf with a pointer to an argument list.

d_wait4
From d_wait4.U:

This variable conditionally defines the HAS_WAIT4 symbol, which indicates the wait4() routine is available.

d_waitpid
From d_waitpid.U:

This variable conditionally defines HAS_WAITPID if waitpid() is available to wait for child process.

d_wcstombs
From d_wcstombs.U:

This variable conditionally defines the HAS_WCSTOMBS symbol, which indicates to the C program that the wcstombs() routine is available to convert wide character strings to multibyte strings.

d_wctomb
From d_wctomb.U:

This variable conditionally defines the HAS_WCTOMB symbol, which indicates to the C program that the wctomb() routine is available to convert a wide character to a multibyte.

d_xenix
From Guess.U:

This variable conditionally defines the symbol XENIX, which alerts the C program that it runs under Xenix.

date
From Loc.U:

This variable is used internally by Configure to determine the full pathname (if any) of the date program. After Configure runs, the value is reset to a plain date and is not useful.

db_hashtype
From i_db.U:

This variable contains the type of the hash structure element in the <db.h> header file. In older versions of DB, it was int, while in newer ones it is u_int32_t.

db_prefixtype
From i_db.U:

This variable contains the type of the prefix structure element in the <db.h> header file. In older versions of DB, it was int, while in newer ones it is size_t.

defvoidused
From voidflags.U:

This variable contains the default value of the VOIDUSED symbol (15).

direntrytype
From i_dirent.U:

This symbol is set to struct direct or struct dirent depending on whether dirent is available or not. You should use this pseudo type to portably declare your directory entries.

dlext
From dlext.U:

This variable contains the extension that is to be used for the dynamically loaded modules that perl generaties.

dlsrc
From dlsrc.U:

This variable contains the name of the dynamic loading file that will be used with the package.

doublesize
From doublesize.U:

This variable contains the value of the DOUBLESIZE symbol, which indicates to the C program how many bytes there are in a double.

drand01
From randfunc.U:

Indicates the macro to be used to generate normalized random numbers. Uses randfunc, often divided by (double) (((unsigned long) 1 << randbits)) in order to normalize the result. In C programs, the macro Drand01 is mapped to drand01.

dynamic_ext
From Extensions.U:

This variable holds a list of XS extension files we want to link dynamically into the package. It is used by Makefile.

e

eagain
From nblock_io.U:

This variable bears the symbolic errno code set by read() when no data is present on the file and non-blocking I/O was enabled (otherwise, read() blocks naturally).

ebcdic
From ebcdic.U:

This variable conditionally defines EBCDIC if this system uses EBCDIC encoding. Among other things, this means that the character ranges are not contiguous. See trnl.U

echo
From Loc.U:

This variable is used internally by Configure to determine the full pathname (if any) of the echo program. After Configure runs, the value is reset to a plain echo and is not useful.

egrep
From Loc.U:

This variable is used internally by Configure to determine the full pathname (if any) of the egrep program. After Configure runs, the value is reset to a plain egrep and is not useful.

emacs
From Loc.U:

This variable is defined but not used by Configure. The value is a plain '' and is not useful.

eunicefix
From Init.U:

When running under Eunice this variable contains a command which will convert a shell script to the proper form of text file for it to be executable by the shell. On other systems it is a no-op.

exe_ext
From Unix.U:

This is an old synonym for _exe.

expr
From Loc.U:

This variable is used internally by Configure to determine the full pathname (if any) of the expr program. After Configure runs, the value is reset to a plain expr and is not useful.

extensions
From Extensions.U:

This variable holds a list of all extension files (both XS and non-xs linked into the package. It is propagated to Config.pm and is typically used to test whether a particular extesion is available.

f

fflushall
From fflushall.U:

This symbol, if defined, tells that to flush all pending stdio output one must loop through all the stdio file handles stored in an array and fflush them. Note that if fflushNULL is defined, fflushall will not even be probed for and will be left undefined.

fflushNULL
From fflushall.U:

This symbol, if defined, tells that fflush(NULL) does flush all pending stdio output.

find
From Loc.U:

This variable is defined but not used by Configure. The value is a plain '' and is not useful.

firstmakefile
From Unix.U:

This variable defines the first file searched by make. On unix, it is makefile (then Makefile). On case-insensitive systems, it might be something else. This is only used to deal with convoluted make depend tricks.

flex
From Loc.U:

This variable is defined but not used by Configure. The value is a plain '' and is not useful.

fpossize
From fpossize.U:

This variable contains the size of a fpostype in bytes.

fpostype
From fpostype.U:

This variable defines Fpos_t to be something like fpos_t, long, uint, or whatever type is used to declare file positions in libc.

freetype
From mallocsrc.U:

This variable contains the return type of free(). It is usually void, but occasionally int.

full_ar
From Loc_ar.U:

This variable contains the full pathname to ar, whether or not the user has specified portability. This is only used in the Makefile.SH.

full_csh
From d_csh.U:

This variable contains the full pathname to csh, whether or not the user has specified portability. This is only used in the compiled C program, and we assume that all systems which can share this executable will have the same full pathname to csh.

full_sed
From Loc_sed.U:

This variable contains the full pathname to sed, whether or not the user has specified portability. This is only used in the compiled C program, and we assume that all systems which can share this executable will have the same full pathname to sed.

g

gccversion
From cc.U:

If GNU cc (gcc) is used, this variable holds 1 or 2 to indicate whether the compiler is version 1 or 2. This is used in setting some of the default cflags. It is set to '' if not gcc.

gidformat
From gidf.U:

This variable contains the format string used for printing a Gid_t.

gidsign
From gidsign.U:

This variable contains the signedness of a gidtype. 1 for unsigned, -1 for signed.

gidsize
From gidsize.U:

This variable contains the size of a gidtype in bytes.

gidtype
From gidtype.U:

This variable defines Gid_t to be something like gid_t, int, ushort, or whatever type is used to declare the return type of getgid(). Typically, it is the type of group ids in the kernel.

glibpth
From libpth.U:

This variable holds the general path (space-separated) used to find libraries. It may contain directories that do not exist on this platform, libpth is the cleaned-up version.

grep
From Loc.U:

This variable is used internally by Configure to determine the full pathname (if any) of the grep program. After Configure runs, the value is reset to a plain grep and is not useful.

groupcat
From nis.U:

This variable contains a command that produces the text of the /etc/group file. This is normally ``cat /etc/group'', but can be ``ypcat group'' when NIS is used. On some systems, such as os390, there may be no equivalent command, in which case this variable is unset.

groupstype
From groupstype.U:

This variable defines Groups_t to be something like gid_t, int, ushort, or whatever type is used for the second argument to getgroups() and setgroups(). Usually, this is the same as gidtype (gid_t), but sometimes it isn't.

gzip
From Loc.U:

This variable is used internally by Configure to determine the full pathname (if any) of the gzip program. After Configure runs, the value is reset to a plain gzip and is not useful.

h

h_fcntl
From h_fcntl.U:

This is variable gets set in various places to tell i_fcntl that <fcntl.h> should be included.

h_sysfile
From h_sysfile.U:

This is variable gets set in various places to tell i_sys_file that <sys/file.h> should be included.

hint
From Oldconfig.U:

Gives the type of hints used for previous answers. May be one of default, recommended or previous.

hostcat
From nis.U:

This variable contains a command that produces the text of the /etc/hosts file. This is normally ``cat /etc/hosts'', but can be ``ypcat hosts'' when NIS is used. On some systems, such as os390, there may be no equivalent command, in which case this variable is unset.

huge
From models.U:

This variable contains a flag which will tell the C compiler and loader to produce a program running with a huge memory model. If the huge model is not supported, contains the flag to produce large model programs. It is up to the Makefile to use this.

i

i16size
From perlxv.U:

This variable is the size of an I16 in bytes.

i16type
From perlxv.U:

This variable contains the C type used for Perl's I16.

i32size
From perlxv.U:

This variable is the size of an I32 in bytes.

i32type
From perlxv.U:

This variable contains the C type used for Perl's I32.

i64size
From perlxv.U:

This variable is the size of an I64 in bytes.

i64type
From perlxv.U:

This variable contains the C type used for Perl's I64.

i8size
From perlxv.U:

This variable is the size of an I8 in bytes.

i8type
From perlxv.U:

This variable contains the C type used for Perl's I8.

i_arpainet
From i_arpainet.U:

This variable conditionally defines the I_ARPA_INET symbol, and indicates whether a C program should include <arpa/inet.h>.

i_bsdioctl
From i_sysioctl.U:

This variable conditionally defines the I_SYS_BSDIOCTL symbol, which indicates to the C program that <sys/bsdioctl.h> exists and should be included.

i_db
From i_db.U:

This variable conditionally defines the I_DB symbol, and indicates whether a C program may include Berkeley's DB include file <db.h>.

i_dbm
From i_dbm.U:

This variable conditionally defines the I_DBM symbol, which indicates to the C program that <dbm.h> exists and should be included.

i_dirent
From i_dirent.U:

This variable conditionally defines I_DIRENT, which indicates to the C program that it should include <dirent.h>.

i_dld
From i_dld.U:

This variable conditionally defines the I_DLD symbol, which indicates to the C program that <dld.h> (GNU dynamic loading) exists and should be included.

i_dlfcn
From i_dlfcn.U:

This variable conditionally defines the I_DLFCN symbol, which indicates to the C program that <dlfcn.h> exists and should be included.

i_fcntl
From i_fcntl.U:

This variable controls the value of I_FCNTL (which tells the C program to include <fcntl.h>).

i_float
From i_float.U:

This variable conditionally defines the I_FLOAT symbol, and indicates whether a C program may include <float.h> to get symbols like DBL_MAX or DBL_MIN, i.e. machine dependent floating point values.

i_gdbm
From i_gdbm.U:

This variable conditionally defines the I_GDBM symbol, which indicates to the C program that <gdbm.h> exists and should be included.

i_grp
From i_grp.U:

This variable conditionally defines the I_GRP symbol, and indicates whether a C program should include <grp.h>.

i_iconv
From i_iconv.U:

This variable conditionally defines the I_ICONV symbol, and indicates whether a C program should include <iconv.h>.

i_ieeefp
From i_ieeefp.U:

This variable conditionally defines the I_IEEEFP symbol, and indicates whether a C program should include <ieeefp.h>.

i_inttypes
From i_inttypes.U:

This variable conditionally defines the I_INTTYPES symbol, and indicates whether a C program should include <inttypes.h>.

i_limits
From i_limits.U:

This variable conditionally defines the I_LIMITS symbol, and indicates whether a C program may include <limits.h> to get symbols like WORD_BIT and friends.

i_locale
From i_locale.U:

This variable conditionally defines the I_LOCALE symbol, and indicates whether a C program should include <locale.h>.

i_machcthr
From i_machcthr.U:

This variable conditionally defines the I_MACH_CTHREADS symbol, and indicates whether a C program should include <mach/cthreads.h>.

i_malloc
From i_malloc.U:

This variable conditionally defines the I_MALLOC symbol, and indicates whether a C program should include <malloc.h>.

i_math
From i_math.U:

This variable conditionally defines the I_MATH symbol, and indicates whether a C program may include <math.h>.

i_memory
From i_memory.U:

This variable conditionally defines the I_MEMORY symbol, and indicates whether a C program should include <memory.h>.

i_mntent
From i_mntent.U:

This variable conditionally defines the I_MNTENT symbol, and indicates whether a C program should include <mntent.h>.

i_ndbm
From i_ndbm.U:

This variable conditionally defines the I_NDBM symbol, which indicates to the C program that <ndbm.h> exists and should be included.

i_netdb
From i_netdb.U:

This variable conditionally defines the I_NETDB symbol, and indicates whether a C program should include <netdb.h>.

i_neterrno
From i_neterrno.U:

This variable conditionally defines the I_NET_ERRNO symbol, which indicates to the C program that <net/errno.h> exists and should be included.

i_netinettcp
From i_netinettcp.U:

This variable conditionally defines the I_NETINET_TCP symbol, and indicates whether a C program should include <netinet/tcp.h>.

i_niin
From i_niin.U:

This variable conditionally defines I_NETINET_IN, which indicates to the C program that it should include <netinet/in.h>. Otherwise, you may try <sys/in.h>.

i_poll
From i_poll.U:

This variable conditionally defines the I_POLL symbol, and indicates whether a C program should include <poll.h>.

i_pthread
From i_pthread.U:

This variable conditionally defines the I_PTHREAD symbol, and indicates whether a C program should include <pthread.h>.

i_pwd
From i_pwd.U:

This variable conditionally defines I_PWD, which indicates to the C program that it should include <pwd.h>.

i_rpcsvcdbm
From i_dbm.U:

This variable conditionally defines the I_RPCSVC_DBM symbol, which indicates to the C program that <rpcsvc/dbm.h> exists and should be included. Some System V systems might need this instead of <dbm.h>.

i_sfio
From i_sfio.U:

This variable conditionally defines the I_SFIO symbol, and indicates whether a C program should include <sfio.h>.

i_sgtty
From i_termio.U:

This variable conditionally defines the I_SGTTY symbol, which indicates to the C program that it should include <sgtty.h> rather than <termio.h>.

i_shadow
From i_shadow.U:

This variable conditionally defines the I_SHADOW symbol, and indicates whether a C program should include <shadow.h>.

i_socks
From i_socks.U:

This variable conditionally defines the I_SOCKS symbol, and indicates whether a C program should include <socks.h>.

i_stdarg
From i_varhdr.U:

This variable conditionally defines the I_STDARG symbol, which indicates to the C program that <stdarg.h> exists and should be included.

i_stddef
From i_stddef.U:

This variable conditionally defines the I_STDDEF symbol, which indicates to the C program that <stddef.h> exists and should be included.

i_stdlib
From i_stdlib.U:

This variable conditionally defines the I_STDLIB symbol, which indicates to the C program that <stdlib.h> exists and should be included.

i_string
From i_string.U:

This variable conditionally defines the I_STRING symbol, which indicates that <string.h> should be included rather than <strings.h>.

i_sunmath
From i_sunmath.U:

This variable conditionally defines the I_SUNMATH symbol, and indicates whether a C program should include <sunmath.h>.

i_sysaccess
From i_sysaccess.U:

This variable conditionally defines the I_SYS_ACCESS symbol, and indicates whether a C program should include <sys/access.h>.

i_sysdir
From i_sysdir.U:

This variable conditionally defines the I_SYS_DIR symbol, and indicates whether a C program should include <sys/dir.h>.

i_sysfile
From i_sysfile.U:

This variable conditionally defines the I_SYS_FILE symbol, and indicates whether a C program should include <sys/file.h> to get R_OK and friends.

i_sysfilio
From i_sysioctl.U:

This variable conditionally defines the I_SYS_FILIO symbol, which indicates to the C program that <sys/filio.h> exists and should be included in preference to <sys/ioctl.h>.

i_sysin
From i_niin.U:

This variable conditionally defines I_SYS_IN, which indicates to the C program that it should include <sys/in.h> instead of <netinet/in.h>.

i_sysioctl
From i_sysioctl.U:

This variable conditionally defines the I_SYS_IOCTL symbol, which indicates to the C program that <sys/ioctl.h> exists and should be included.

i_syslog
From i_syslog.U:

This variable conditionally defines the I_SYSLOG symbol, and indicates whether a C program should include <syslog.h>.

i_sysmman
From i_sysmman.U:

This variable conditionally defines the I_SYS_MMAN symbol, and indicates whether a C program should include <sys/mman.h>.

i_sysmode
From i_sysmode.U:

This variable conditionally defines the I_SYSMODE symbol, and indicates whether a C program should include <sys/mode.h>.

i_sysmount
From i_sysmount.U:

This variable conditionally defines the I_SYSMOUNT symbol, and indicates whether a C program should include <sys/mount.h>.

i_sysndir
From i_sysndir.U:

This variable conditionally defines the I_SYS_NDIR symbol, and indicates whether a C program should include <sys/ndir.h>.

i_sysparam
From i_sysparam.U:

This variable conditionally defines the I_SYS_PARAM symbol, and indicates whether a C program should include <sys/param.h>.

i_sysresrc
From i_sysresrc.U:

This variable conditionally defines the I_SYS_RESOURCE symbol, and indicates whether a C program should include <sys/resource.h>.

i_syssecrt
From i_syssecrt.U:

This variable conditionally defines the I_SYS_SECURITY symbol, and indicates whether a C program should include <sys/security.h>.

i_sysselct
From i_sysselct.U:

This variable conditionally defines I_SYS_SELECT, which indicates to the C program that it should include <sys/select.h> in order to get the definition of struct timeval.

i_syssockio
From i_sysioctl.U:

This variable conditionally defines I_SYS_SOCKIO to indicate to the C program that socket ioctl codes may be found in <sys/sockio.h> instead of <sys/ioctl.h>.

i_sysstat
From i_sysstat.U:

This variable conditionally defines the I_SYS_STAT symbol, and indicates whether a C program should include <sys/stat.h>.

i_sysstatfs
From i_sysstatfs.U:

This variable conditionally defines the I_SYSSTATFS symbol, and indicates whether a C program should include <sys/statfs.h>.

i_sysstatvfs
From i_sysstatvfs.U:

This variable conditionally defines the I_SYSSTATVFS symbol, and indicates whether a C program should include <sys/statvfs.h>.

i_systime
From i_time.U:

This variable conditionally defines I_SYS_TIME, which indicates to the C program that it should include <sys/time.h>.

i_systimek
From i_time.U:

This variable conditionally defines I_SYS_TIME_KERNEL, which indicates to the C program that it should include <sys/time.h> with KERNEL defined.

i_systimes
From i_systimes.U:

This variable conditionally defines the I_SYS_TIMES symbol, and indicates whether a C program should include <sys/times.h>.

i_systypes
From i_systypes.U:

This variable conditionally defines the I_SYS_TYPES symbol, and indicates whether a C program should include <sys/types.h>.

i_sysuio
From i_sysuio.U:

This variable conditionally defines the I_SYSUIO symbol, and indicates whether a C program should include <sys/uio.h>.

i_sysun
From i_sysun.U:

This variable conditionally defines I_SYS_UN, which indicates to the C program that it should include <sys/un.h> to get UNIX domain socket definitions.

i_sysutsname
From i_sysutsname.U:

This variable conditionally defines the I_SYSUTSNAME symbol, and indicates whether a C program should include <sys/utsname.h>.

i_sysvfs
From i_sysvfs.U:

This variable conditionally defines the I_SYSVFS symbol, and indicates whether a C program should include <sys/vfs.h>.

i_syswait
From i_syswait.U:

This variable conditionally defines I_SYS_WAIT, which indicates to the C program that it should include <sys/wait.h>.

i_termio
From i_termio.U:

This variable conditionally defines the I_TERMIO symbol, which indicates to the C program that it should include <termio.h> rather than <sgtty.h>.

i_termios
From i_termio.U:

This variable conditionally defines the I_TERMIOS symbol, which indicates to the C program that the POSIX <termios.h> file is to be included.

i_time
From i_time.U:

This variable conditionally defines I_TIME, which indicates to the C program that it should include <time.h>.

i_unistd
From i_unistd.U:

This variable conditionally defines the I_UNISTD symbol, and indicates whether a C program should include <unistd.h>.

i_ustat
From i_ustat.U:

This variable conditionally defines the I_USTAT symbol, and indicates whether a C program should include <ustat.h>.

i_utime
From i_utime.U:

This variable conditionally defines the I_UTIME symbol, and indicates whether a C program should include <utime.h>.

i_values
From i_values.U:

This variable conditionally defines the I_VALUES symbol, and indicates whether a C program may include <values.h> to get symbols like MAXLONG and friends.

i_varargs
From i_varhdr.U:

This variable conditionally defines I_VARARGS, which indicates to the C program that it should include <varargs.h>.

i_varhdr
From i_varhdr.U:

Contains the name of the header to be included to get va_dcl definition. Typically one of varargs.h or stdarg.h.

i_vfork
From i_vfork.U:

This variable conditionally defines the I_VFORK symbol, and indicates whether a C program should include vfork.h.

ignore_versioned_solibs
From libs.U:

This variable should be non-empty if non-versioned shared libraries (libfoo.so.x.y) are to be ignored (because they cannot be linked against).

inc_version_list
From inc_version_list.U:

This variable specifies the list of subdirectories in over which perl.c:incpush() and lib/lib.pm will automatically search when adding directories to @INC. The elements in the list are separated by spaces. This is only useful if you have a perl library directory tree structured like the default one. See INSTALL for how this works. The versioned site_perl directory was introduced in 5.005, so that is the lowest possible value.

inc_version_list_init
From inc_version_list.U:

This variable holds the same list as inc_version_list, but each item is enclosed in double quotes and separated by commas, suitable for use in the PERL_INC_VERSION_LIST initialization.

incpath
From usrinc.U:

This variable must preceed the normal include path to get hte right one, as in $incpath/usr/include or $incpath/usr/lib. Value can be ``'' or /bsd43 on mips.

inews
From Loc.U:

This variable is defined but not used by Configure. The value is a plain '' and is not useful.

installarchlib
From archlib.U:

This variable is really the same as archlibexp but may differ on those systems using AFS. For extra portability, only this variable should be used in makefiles.

installbin
From bin.U:

This variable is the same as binexp unless AFS is running in which case the user is explicitely prompted for it. This variable should always be used in your makefiles for maximum portability.

installman1dir
From man1dir.U:

This variable is really the same as man1direxp, unless you are using AFS in which case it points to the read/write location whereas man1direxp only points to the read-only access location. For extra portability, you should only use this variable within your makefiles.

installman3dir
From man3dir.U:

This variable is really the same as man3direxp, unless you are using AFS in which case it points to the read/write location whereas man3direxp only points to the read-only access location. For extra portability, you should only use this variable within your makefiles.

installprefix
From installprefix.U:

This variable holds the name of the directory below which ``make install'' will install the package. For most users, this is the same as prefix. However, it is useful for installing the software into a different (usually temporary) location after which it can be bundled up and moved somehow to the final location specified by prefix.

installprefixexp
From installprefix.U:

This variable holds the full absolute path of installprefix with all ~-expansion done.

installprivlib
From privlib.U:

This variable is really the same as privlibexp but may differ on those systems using AFS. For extra portability, only this variable should be used in makefiles.

installscript
From scriptdir.U:

This variable is usually the same as scriptdirexp, unless you are on a system running AFS, in which case they may differ slightly. You should always use this variable within your makefiles for portability.

installsitearch
From sitearch.U:

This variable is really the same as sitearchexp but may differ on those systems using AFS. For extra portability, only this variable should be used in makefiles.

installsitebin
From sitebin.U:

This variable is usually the same as sitebinexp, unless you are on a system running AFS, in which case they may differ slightly. You should always use this variable within your makefiles for portability.

installsitelib
From sitelib.U:

This variable is really the same as sitelibexp but may differ on those systems using AFS. For extra portability, only this variable should be used in makefiles.

installstyle
From installstyle.U:

This variable describes the style of the perl installation. This is intended to be useful for tools that need to manipulate entire perl distributions. Perl itself doesn't use this to find its libraries -- the library directories are stored directly in Config.pm. Currently, there are only two styles: lib and lib/perl5. The default library locations (e.g. privlib, sitelib) are either $prefix/lib or $prefix/lib/perl5. The former is useful if $prefix is a directory dedicated to perl (e.g. /opt/perl), while the latter is useful if $prefix is shared by many packages, e.g. if $prefix=/usr/local.

        This may later be extended to include other information, so
        be careful with pattern-matching on the results.
        For compatibility with F<perl5.005> and earlier, the default
        setting is based on whether or not $prefix contains the string
C<perl>.

installusrbinperl
From instubperl.U:

This variable tells whether Perl should be installed also as /usr/bin/perl in addition to $installbin/perl

installvendorarch
From vendorarch.U:

This variable is really the same as vendorarchexp but may differ on those systems using AFS. For extra portability, only this variable should be used in makefiles.

installvendorbin
From vendorbin.U:

This variable is really the same as vendorbinexp but may differ on those systems using AFS. For extra portability, only this variable should be used in makefiles.

installvendorlib
From vendorlib.U:

This variable is really the same as vendorlibexp but may differ on those systems using AFS. For extra portability, only this variable should be used in makefiles.

intsize
From intsize.U:

This variable contains the value of the INTSIZE symbol, which indicates to the C program how many bytes there are in an int.

ivdformat
From perlxvf.U:

This variable contains the format string used for printing a Perl IV as a signed decimal integer.

ivsize
From perlxv.U:

This variable is the size of an IV in bytes.

ivtype
From perlxv.U:

This variable contains the C type used for Perl's IV.

k

known_extensions
From Extensions.U:

This variable holds a list of all XS extensions included in the package.

ksh
From Loc.U:

This variable is defined but not used by Configure. The value is a plain '' and is not useful.

l

large
From models.U:

This variable contains a flag which will tell the C compiler and loader to produce a program running with a large memory model. It is up to the Makefile to use this.

ld
From dlsrc.U:

This variable indicates the program to be used to link libraries for dynamic loading. On some systems, it is ld. On ELF systems, it should be $cc. Mostly, we'll try to respect the hint file setting.

lddlflags
From dlsrc.U:

This variable contains any special flags that might need to be passed to $ld to create a shared library suitable for dynamic loading. It is up to the makefile to use it. For hpux, it should be -b. For sunos 4.1, it is empty.

ldflags
From ccflags.U:

This variable contains any additional C loader flags desired by the user. It is up to the Makefile to use this.

ldlibpthname
From libperl.U:

This variable holds the name of the shared library search path, often LD_LIBRARY_PATH. To get an empty string, the hints file must set this to none.

less
From Loc.U:

This variable is used internally by Configure to determine the full pathname (if any) of the less program. After Configure runs, the value is reset to a plain less and is not useful.

lib_ext
From Unix.U:

This is an old synonym for _a.

libc
From libc.U:

This variable contains the location of the C library.

libperl
From libperl.U:

The perl executable is obtained by linking perlmain.c with libperl, any static extensions (usually just DynaLoader), and any other libraries needed on this system. libperl is usually libperl.a, but can also be libperl.so.xxx if the user wishes to build a perl executable with a shared library.

libpth
From libpth.U:

This variable holds the general path (space-separated) used to find libraries. It is intended to be used by other units.

libs
From libs.U:

This variable holds the additional libraries we want to use. It is up to the Makefile to deal with it.

libsdirs
From libs.U:

This variable holds the directory names aka dirnames of the libraries we found and accepted, duplicates are removed.

libsfiles
From libs.U:

This variable holds the filenames aka basenames of the libraries we found and accepted.

libsfound
From libs.U:

This variable holds the full pathnames of the libraries we found and accepted.

libspath
From libs.U:

This variable holds the directory names probed for libraries.

libswanted
From Myinit.U:

This variable holds a list of all the libraries we want to search. The order is chosen to pick up the c library ahead of ucb or bsd libraries for SVR4.

line
From Loc.U:

This variable is defined but not used by Configure. The value is a plain '' and is not useful.

lint
From Loc.U:

This variable is defined but not used by Configure. The value is a plain '' and is not useful.

lkflags
From ccflags.U:

This variable contains any additional C partial linker flags desired by the user. It is up to the Makefile to use this.

ln
From Loc.U:

This variable is used internally by Configure to determine the full pathname (if any) of the ln program. After Configure runs, the value is reset to a plain ln and is not useful.

lns
From lns.U:

This variable holds the name of the command to make symbolic links (if they are supported). It can be used in the Makefile. It is either ln -s or ln

locincpth
From ccflags.U:

This variable contains a list of additional directories to be searched by the compiler. The appropriate -I directives will be added to ccflags. This is intended to simplify setting local directories from the Configure command line. It's not much, but it parallels the loclibpth stuff in libpth.U.

loclibpth
From libpth.U:

This variable holds the paths (space-separated) used to find local libraries. It is prepended to libpth, and is intended to be easily set from the command line.

longdblsize
From d_longdbl.U:

This variable contains the value of the LONG_DOUBLESIZE symbol, which indicates to the C program how many bytes there are in a long double, if this system supports long doubles.

longlongsize
From d_longlong.U:

This variable contains the value of the LONGLONGSIZE symbol, which indicates to the C program how many bytes there are in a long long, if this system supports long long.

longsize
From intsize.U:

This variable contains the value of the LONGSIZE symbol, which indicates to the C program how many bytes there are in a long.

lp
From Loc.U:

This variable is defined but not used by Configure. The value is a plain '' and is not useful.

lpr
From Loc.U:

This variable is defined but not used by Configure. The value is a plain '' and is not useful.

ls
From Loc.U:

This variable is used internally by Configure to determine the full pathname (if any) of the ls program. After Configure runs, the value is reset to a plain ls and is not useful.

lseeksize
From lseektype.U:

This variable defines lseektype to be something like off_t, long, or whatever type is used to declare lseek offset's type in the kernel (which also appears to be lseek's return type).

lseektype
From lseektype.U:

This variable defines lseektype to be something like off_t, long, or whatever type is used to declare lseek offset's type in the kernel (which also appears to be lseek's return type).

m

mail
From Loc.U:

This variable is defined but not used by Configure. The value is a plain '' and is not useful.

mailx
From Loc.U:

This variable is defined but not used by Configure. The value is a plain '' and is not useful.

make
From Loc.U:

This variable is used internally by Configure to determine the full pathname (if any) of the make program. After Configure runs, the value is reset to a plain make and is not useful.

make_set_make
From make.U:

Some versions of make set the variable MAKE. Others do not. This variable contains the string to be included in Makefile.SH so that MAKE is set if needed, and not if not needed. Possible values are: make_set_make=# # If your make program handles this for you, make_set_make=MAKE=$make # if it doesn't. I used a comment character so that we can distinguish a set value (from a previous config.sh or Configure -D option) from an uncomputed value.

mallocobj
From mallocsrc.U:

This variable contains the name of the malloc.o that this package generates, if that malloc.o is preferred over the system malloc. Otherwise the value is null. This variable is intended for generating Makefiles. See mallocsrc.

mallocsrc
From mallocsrc.U:

This variable contains the name of the malloc.c that comes with the package, if that malloc.c is preferred over the system malloc. Otherwise the value is null. This variable is intended for generating Makefiles.

malloctype
From mallocsrc.U:

This variable contains the kind of ptr returned by malloc and realloc.

man1dir
From man1dir.U:

This variable contains the name of the directory in which manual source pages are to be put. It is the responsibility of the Makefile.SH to get the value of this into the proper command. You must be prepared to do the ~name expansion yourself.

man1direxp
From man1dir.U:

This variable is the same as the man1dir variable, but is filename expanded at configuration time, for convenient use in makefiles.

man1ext
From man1dir.U:

This variable contains the extension that the manual page should have: one of n, l, or 1. The Makefile must supply the .. See man1dir.

man3dir
From man3dir.U:

This variable contains the name of the directory in which manual source pages are to be put. It is the responsibility of the Makefile.SH to get the value of this into the proper command. You must be prepared to do the ~name expansion yourself.

man3direxp
From man3dir.U:

This variable is the same as the man3dir variable, but is filename expanded at configuration time, for convenient use in makefiles.

man3ext
From man3dir.U:

This variable contains the extension that the manual page should have: one of n, l, or 3. The Makefile must supply the .. See man3dir.

M

Mcc
From Loc.U:

This variable is used internally by Configure to determine the full pathname (if any) of the Mcc program. After Configure runs, the value is reset to a plain Mcc and is not useful.

medium
From models.U:

This variable contains a flag which will tell the C compiler and loader to produce a program running with a medium memory model. If the medium model is not supported, contains the flag to produce large model programs. It is up to the Makefile to use this.

mips_type
From usrinc.U:

This variable holds the environment type for the mips system. Possible values are ``BSD 4.3'' and ``System V''.

mkdir
From Loc.U:

This variable is used internally by Configure to determine the full pathname (if any) of the mkdir program. After Configure runs, the value is reset to a plain mkdir and is not useful.

mmaptype
From d_mmap.U:

This symbol contains the type of pointer returned by mmap() (and simultaneously the type of the first argument). It can be void * or caddr_t.

models
From models.U:

This variable contains the list of memory models supported by this system. Possible component values are none, split, unsplit, small, medium, large, and huge. The component values are space separated.

modetype
From modetype.U:

This variable defines modetype to be something like mode_t, int, unsigned short, or whatever type is used to declare file modes for system calls.

more
From Loc.U:

This variable is used internally by Configure to determine the full pathname (if any) of the more program. After Configure runs, the value is reset to a plain more and is not useful.

multiarch
From multiarch.U:

This variable conditionally defines the MULTIARCH symbol which signifies the presence of multiplatform files. This is normally set by hints files.

mv
From Loc.U:

This variable is defined but not used by Configure. The value is a plain '' and is not useful.

myarchname
From archname.U:

This variable holds the architecture name computed by Configure in a previous run. It is not intended to be perused by any user and should never be set in a hint file.

mydomain
From myhostname.U:

This variable contains the eventual value of the MYDOMAIN symbol, which is the domain of the host the program is going to run on. The domain must be appended to myhostname to form a complete host name. The dot comes with mydomain, and need not be supplied by the program.

myhostname
From myhostname.U:

This variable contains the eventual value of the MYHOSTNAME symbol, which is the name of the host the program is going to run on. The domain is not kept with hostname, but must be gotten from mydomain. The dot comes with mydomain, and need not be supplied by the program.

myuname
From Oldconfig.U:

The output of uname -a if available, otherwise the hostname. On Xenix, pseudo variables assignments in the output are stripped, thank you. The whole thing is then lower-cased.

n

n
From n.U:

This variable contains the -n flag if that is what causes the echo command to suppress newline. Otherwise it is null. Correct usage is $echo $n ``prompt for a question: $c''.

netdb_hlen_type
From netdbtype.U:

This variable holds the type used for the 2nd argument to gethostbyaddr(). Usually, this is int or size_t or unsigned. This is only useful if you have gethostbyaddr(), naturally.

netdb_host_type
From netdbtype.U:

This variable holds the type used for the 1st argument to gethostbyaddr(). Usually, this is char * or void *, possibly with or without a const prefix. This is only useful if you have gethostbyaddr(), naturally.

netdb_name_type
From netdbtype.U:

This variable holds the type used for the argument to gethostbyname(). Usually, this is char * or const char *. This is only useful if you have gethostbyname(), naturally.

netdb_net_type
From netdbtype.U:

This variable holds the type used for the 1st argument to getnetbyaddr(). Usually, this is int or long. This is only useful if you have getnetbyaddr(), naturally.

nm
From Loc.U:

This variable is used internally by Configure to determine the full pathname (if any) of the nm program. After Configure runs, the value is reset to a plain nm and is not useful.

nm_opt
From usenm.U:

This variable holds the options that may be necessary for nm.

nm_so_opt
From usenm.U:

This variable holds the options that may be necessary for nm to work on a shared library but that can not be used on an archive library. Currently, this is only used by Linux, where nm --dynamic is *required* to get symbols from an ELF library which has been stripped, but nm --dynamic is *fatal* on an archive library. Maybe Linux should just always set usenm=false.

nonxs_ext
From Extensions.U:

This variable holds a list of all non-xs extensions included in the package. All of them will be built.

nroff
From Loc.U:

This variable is used internally by Configure to determine the full pathname (if any) of the nroff program. After Configure runs, the value is reset to a plain nroff and is not useful.

nvsize
From perlxv.U:

This variable is the size of an NV in bytes.

nvtype
From perlxv.U:

This variable contains the C type used for Perl's NV.

o

o_nonblock
From nblock_io.U:

This variable bears the symbol value to be used during open() or fcntl() to turn on non-blocking I/O for a file descriptor. If you wish to switch between blocking and non-blocking, you may try ioctl(FIOSNBIO) instead, but that is only supported by some devices.

obj_ext
From Unix.U:

This is an old synonym for _o.

old_pthread_create_joinable
From d_pthrattrj.U:

This variable defines the constant to use for creating joinable (aka undetached) pthreads. Unused if pthread.h defines PTHREAD_CREATE_JOINABLE. If used, possible values are PTHREAD_CREATE_UNDETACHED and __UNDETACHED.

optimize
From ccflags.U:

This variable contains any optimizer/debugger flag that should be used. It is up to the Makefile to use it.

orderlib
From orderlib.U:

This variable is true if the components of libraries must be ordered (with `lorder $* | tsort`) before placing them in an archive. Set to false if ranlib or ar can generate random libraries.

osname
From Oldconfig.U:

This variable contains the operating system name (e.g. sunos, solaris, hpux, etc.). It can be useful later on for setting defaults. Any spaces are replaced with underscores. It is set to a null string if we can't figure it out.

osvers
From Oldconfig.U:

This variable contains the operating system version (e.g. 4.1.3, 5.2, etc.). It is primarily used for helping select an appropriate hints file, but might be useful elsewhere for setting defaults. It is set to '' if we can't figure it out. We try to be flexible about how much of the version number to keep, e.g. if 4.1.1, 4.1.2, and 4.1.3 are essentially the same for this package, hints files might just be os_4.0 or os_4.1, etc., not keeping separate files for each little release.

p

package
From package.U:

This variable contains the name of the package being constructed. It is primarily intended for the use of later Configure units.

pager
From pager.U:

This variable contains the name of the preferred pager on the system. Usual values are (the full pathnames of) more, less, pg, or cat.

passcat
From nis.U:

This variable contains a command that produces the text of the /etc/passwd file. This is normally ``cat /etc/passwd'', but can be ``ypcat passwd'' when NIS is used. On some systems, such as os390, there may be no equivalent command, in which case this variable is unset.

patchlevel
From patchlevel.U:

The patchlevel level of this package. The value of patchlevel comes from the patchlevel.h file. In a version number such as 5.6.1, this is the 6. In patchlevel.h, this is referred to as PERL_VERSION.

path_sep
From Unix.U:

This is an old synonym for p_ in Head.U, the character used to separate elements in the command shell search PATH.

perl5
From perl5.U:

This variable contains the full path (if any) to a previously installed perl5.005 or later suitable for running the script to determine inc_version_list.

perl
From Loc.U:

This variable is defined but not used by Configure. The value is a plain '' and is not useful.

P

PERL_REVISION
From Oldsyms.U:

In a Perl version number such as 5.6.2, this is the 5. This value is manually set in patchlevel.h

PERL_SUBVERSION
From Oldsyms.U:

In a Perl version number such as 5.6.2, this is the 2. Values greater than 50 represent potentially unstable development subversions. This value is manually set in patchlevel.h

PERL_VERSION
From Oldsyms.U:

In a Perl version number such as 5.6.2, this is the 6. This value is manually set in patchlevel.h

perladmin
From perladmin.U:

Electronic mail address of the perl5 administrator.

perlpath
From perlpath.U:

This variable contains the eventual value of the PERLPATH symbol, which contains the name of the perl interpreter to be used in shell scripts and in the ``eval exec'' idiom.

pg
From Loc.U:

This variable is used internally by Configure to determine the full pathname (if any) of the pg program. After Configure runs, the value is reset to a plain pg and is not useful.

phostname
From myhostname.U:

This variable contains the eventual value of the PHOSTNAME symbol, which is a command that can be fed to popen() to get the host name. The program should probably not presume that the domain is or isn't there already.

pidtype
From pidtype.U:

This variable defines PIDTYPE to be something like pid_t, int, ushort, or whatever type is used to declare process ids in the kernel.

plibpth
From libpth.U:

Holds the private path used by Configure to find out the libraries. Its value is prepend to libpth. This variable takes care of special machines, like the mips. Usually, it should be empty.

pm_apiversion
From xs_apiversion.U:

This variable contains the version of the oldest perl compatible with the present perl. (That is, pure perl modules written for $pm_apiversion will still work for the current version). perl.c:incpush() and lib/lib.pm will automatically search in $sitelib for older directories across major versions back to pm_apiversion. This is only useful if you have a perl library directory tree structured like the default one. The versioned site_perl library was introduced in 5.005, so that's the default setting for this variable. It's hard to imagine it changing before Perl6. It is included here for symmetry with xs_apiveprsion -- the searching algorithms will (presumably) be similar. See the INSTALL file for how this works.

pmake
From Loc.U:

This variable is defined but not used by Configure. The value is a plain '' and is not useful.

pr
From Loc.U:

This variable is defined but not used by Configure. The value is a plain '' and is not useful.

prefix
From prefix.U:

This variable holds the name of the directory below which the user will install the package. Usually, this is /usr/local, and executables go in /usr/local/bin, library stuff in /usr/local/lib, man pages in /usr/local/man, etc. It is only used to set defaults for things in bin.U, mansrc.U, privlib.U, or scriptdir.U.

prefixexp
From prefix.U:

This variable holds the full absolute path of the directory below which the user will install the package. Derived from prefix.

privlib
From privlib.U:

This variable contains the eventual value of the PRIVLIB symbol, which is the name of the private library for this package. It may have a ~ on the front. It is up to the makefile to eventually create this directory while performing installation (with ~ substitution).

privlibexp
From privlib.U:

This variable is the ~name expanded version of privlib, so that you may use it directly in Makefiles or shell scripts.

prototype
From prototype.U:

This variable holds the eventual value of CAN_PROTOTYPE, which indicates the C compiler can handle funciton prototypes.

ptrsize
From ptrsize.U:

This variable contains the value of the PTRSIZE symbol, which indicates to the C program how many bytes there are in a pointer.

q

quadkind
From quadtype.U:

This variable, if defined, encodes the type of a quad: 1 = int, 2 = long, 3 = long long, 4 = int64_t.

quadtype
From quadtype.U:

This variable defines Quad_t to be something like long, int, long long, int64_t, or whatever type is used for 64-bit integers.

r

randbits
From randfunc.U:

Indicates how many bits are produced by the function used to generate normalized random numbers.

randfunc
From randfunc.U:

Indicates the name of the random number function to use. Values include drand48, random, and rand. In C programs, the Drand01 macro is defined to generate uniformly distributed random numbers over the range [0., 1.[ (see drand01 and nrand).

randseedtype
From randfunc.U:

Indicates the type of the argument of the seedfunc.

ranlib
From orderlib.U:

This variable is set to the pathname of the ranlib program, if it is needed to generate random libraries. Set to : if ar can generate random libraries or if random libraries are not supported

rd_nodata
From nblock_io.U:

This variable holds the return code from read() when no data is present. It should be -1, but some systems return 0 when O_NDELAY is used, which is a shame because you cannot make the difference between no data and an EOF.. Sigh!

revision
From patchlevel.U:

The value of revision comes from the patchlevel.h file. In a version number such as 5.6.1, this is the 5. In patchlevel.h, this is referred to as PERL_REVISION.

rm
From Loc.U:

This variable is used internally by Configure to determine the full pathname (if any) of the rm program. After Configure runs, the value is reset to a plain rm and is not useful.

rmail
From Loc.U:

This variable is defined but not used by Configure. The value is a plain '' and is not useful.

runnm
From usenm.U:

This variable contains true or false depending whether the nm extraction should be performed or not, according to the value of usenm and the flags on the Configure command line.

s

sched_yield
From d_pthread_y.U:

This variable defines the way to yield the execution of the current thread.

scriptdir
From scriptdir.U:

This variable holds the name of the directory in which the user wants to put publicly scripts for the package in question. It is either the same directory as for binaries, or a special one that can be mounted across different architectures, like /usr/share. Programs must be prepared to deal with ~name expansion.

scriptdirexp
From scriptdir.U:

This variable is the same as scriptdir, but is filename expanded at configuration time, for programs not wanting to bother with it.

sed
From Loc.U:

This variable is used internally by Configure to determine the full pathname (if any) of the sed program. After Configure runs, the value is reset to a plain sed and is not useful.

seedfunc
From randfunc.U:

Indicates the random number generating seed function. Values include srand48, srandom, and srand.

selectminbits
From selectminbits.U:

This variable holds the minimum number of bits operated by select. That is, if you do select(n, ...), how many bits at least will be cleared in the masks if some activity is detected. Usually this is either n or 32*ceil(n/32), especially many little-endians do the latter. This is only useful if you have select(), naturally.

selecttype
From selecttype.U:

This variable holds the type used for the 2nd, 3rd, and 4th arguments to select. Usually, this is fd_set *, if HAS_FD_SET is defined, and int * otherwise. This is only useful if you have select(), naturally.

sendmail
From Loc.U:

This variable is defined but not used by Configure. The value is a plain '' and is not useful.

sh
From sh.U:

This variable contains the full pathname of the shell used on this system to execute Bourne shell scripts. Usually, this will be /bin/sh, though it's possible that some systems will have /bin/ksh, /bin/pdksh, /bin/ash, /bin/bash, or even something such as D:/bin/sh.exe. This unit comes before Options.U, so you can't set sh with a -D option, though you can override this (and startsh) with -O -Dsh=/bin/whatever -Dstartsh=whatever

shar
From Loc.U:

This variable is defined but not used by Configure. The value is a plain '' and is not useful.

sharpbang
From spitshell.U:

This variable contains the string #! if this system supports that construct.

shmattype
From d_shmat.U:

This symbol contains the type of pointer returned by shmat(). It can be void * or char *.

shortsize
From intsize.U:

This variable contains the value of the SHORTSIZE symbol which indicates to the C program how many bytes there are in a short.

shrpenv
From libperl.U:

If the user builds a shared libperl.so, then we need to tell the perl executable where it will be able to find the installed libperl.so. One way to do this on some systems is to set the environment variable LD_RUN_PATH to the directory that will be the final location of the shared libperl.so. The makefile can use this with something like $shrpenv $(CC) -o perl perlmain.o $libperl $libs Typical values are shrpenv=``env LD_RUN_PATH=$archlibexp/CORE'' or shrpenv='' See the main perl Makefile.SH for actual working usage. Alternatively, we might be able to use a command line option such as -R $archlibexp/CORE (Solaris, NetBSD) or -Wl,-rpath $archlibexp/CORE (Linux).

shsharp
From spitshell.U:

This variable tells further Configure units whether your sh can handle # comments.

sig_count
From sig_name.U:

This variable holds a number larger than the largest valid signal number. This is usually the same as the NSIG macro.

sig_name
From sig_name.U:

This variable holds the signal names, space separated. The leading SIG in signal name is removed. A ZERO is prepended to the list. This is currently not used.

sig_name_init
From sig_name.U:

This variable holds the signal names, enclosed in double quotes and separated by commas, suitable for use in the SIG_NAME definition below. A ZERO is prepended to the list, and the list is terminated with a plain 0. The leading SIG in signal names is removed. See sig_num.

sig_num
From sig_name.U:

This variable holds the signal numbers, space separated. A ZERO is prepended to the list (corresponding to the fake SIGZERO), and the list is terminated with a 0. Those numbers correspond to the value of the signal listed in the same place within the sig_name list.

sig_num_init
From sig_name.U:

This variable holds the signal numbers, enclosed in double quotes and separated by commas, suitable for use in the SIG_NUM definition below. A ZERO is prepended to the list, and the list is terminated with a plain 0.

signal_t
From d_voidsig.U:

This variable holds the type of the signal handler (void or int).

sitearch
From sitearch.U:

This variable contains the eventual value of the SITEARCH symbol, which is the name of the private library for this package. It may have a ~ on the front. It is up to the makefile to eventually create this directory while performing installation (with ~ substitution). The standard distribution will put nothing in this directory. After perl has been installed, users may install their own local architecture-dependent modules in this directory with MakeMaker Makefile.PL or equivalent. See INSTALL for details.

sitearchexp
From sitearch.U:

This variable is the ~name expanded version of sitearch, so that you may use it directly in Makefiles or shell scripts.

sitebin
From sitebin.U:

This variable holds the name of the directory in which the user wants to put add-on publicly executable files for the package in question. It is most often a local directory such as /usr/local/bin. Programs using this variable must be prepared to deal with ~name substitution. The standard distribution will put nothing in this directory. After perl has been installed, users may install their own local executables in this directory with MakeMaker Makefile.PL or equivalent. See INSTALL for details.

sitebinexp
From sitebin.U:

This is the same as the sitebin variable, but is filename expanded at configuration time, for use in your makefiles.

sitelib
From sitelib.U:

This variable contains the eventual value of the SITELIB symbol, which is the name of the private library for this package. It may have a ~ on the front. It is up to the makefile to eventually create this directory while performing installation (with ~ substitution). The standard distribution will put nothing in this directory. After perl has been installed, users may install their own local architecture-independent modules in this directory with MakeMaker Makefile.PL or equivalent. See INSTALL for details.

sitelib_stem
From sitelib.U:

This variable is $sitelibexp with any trailing version-specific component removed. The elements in inc_version_list (inc_version_list.U) can be tacked onto this variable to generate a list of directories to search.

sitelibexp
From sitelib.U:

This variable is the ~name expanded version of sitelib, so that you may use it directly in Makefiles or shell scripts.

siteprefix
From siteprefix.U:

This variable holds the full absolute path of the directory below which the user will install add-on packages. See INSTALL for usage and examples.

siteprefixexp
From siteprefix.U:

This variable holds the full absolute path of the directory below which the user will install add-on packages. Derived from siteprefix.

sizesize
From sizesize.U:

This variable contains the size of a sizetype in bytes.

sizetype
From sizetype.U:

This variable defines sizetype to be something like size_t, unsigned long, or whatever type is used to declare length parameters for string functions.

sleep
From Loc.U:

This variable is defined but not used by Configure. The value is a plain '' and is not useful.

smail
From Loc.U:

This variable is defined but not used by Configure. The value is a plain '' and is not useful.

small
From models.U:

This variable contains a flag which will tell the C compiler and loader to produce a program running with a small memory model. It is up to the Makefile to use this.

so
From so.U:

This variable holds the extension used to identify shared libraries (also known as shared objects) on the system. Usually set to so.

sockethdr
From d_socket.U:

This variable has any cpp -I flags needed for socket support.

socketlib
From d_socket.U:

This variable has the names of any libraries needed for socket support.

socksizetype
From socksizetype.U:

This variable holds the type used for the size argument for various socket calls like accept. Usual values include socklen_t, size_t, and int.

sort
From Loc.U:

This variable is used internally by Configure to determine the full pathname (if any) of the sort program. After Configure runs, the value is reset to a plain sort and is not useful.

spackage
From package.U:

This variable contains the name of the package being constructed, with the first letter uppercased, i.e. suitable for starting sentences.

spitshell
From spitshell.U:

This variable contains the command necessary to spit out a runnable shell on this system. It is either cat or a grep -v for # comments.

split
From models.U:

This variable contains a flag which will tell the C compiler and loader to produce a program that will run in separate I and D space, for those machines that support separation of instruction and data space. It is up to the Makefile to use this.

sPRId64
From quadfio.U:

This variable, if defined, contains the string used by stdio to format 64-bit decimal numbers (format d) for output.

sPRIeldbl
From longdblfio.U:

This variable, if defined, contains the string used by stdio to format long doubles (format e) for output.

sPRIEldbl
From longdblfio.U:

This variable, if defined, contains the string used by stdio to format long doubles (format E) for output.

sPRIfldbl
From longdblfio.U:

This variable, if defined, contains the string used by stdio to format long doubles (format f) for output.

sPRIFldbl
From longdblfio.U:

This variable, if defined, contains the string used by stdio to format long doubles (format F) for output.

sPRIgldbl
From longdblfio.U:

This variable, if defined, contains the string used by stdio to format long doubles (format g) for output.

sPRIGldbl
From longdblfio.U:

This variable, if defined, contains the string used by stdio to format long doubles (format G) for output.

sPRIi64
From quadfio.U:

This variable, if defined, contains the string used by stdio to format 64-bit decimal numbers (format i) for output.

sPRIo64
From quadfio.U:

This variable, if defined, contains the string used by stdio to format 64-bit octal numbers (format o) for output.

sPRIu64
From quadfio.U:

This variable, if defined, contains the string used by stdio to format 64-bit unsigned decimal numbers (format u) for output.

sPRIx64
From quadfio.U:

This variable, if defined, contains the string used by stdio to format 64-bit hexadecimal numbers (format x) for output.

sPRIX64
From quadfio.U:

This variable, if defined, contains the string used by stdio to format 64-bit hExADECimAl numbers (format X) for output.

src
From src.U:

This variable holds the path to the package source. It is up to the Makefile to use this variable and set VPATH accordingly to find the sources remotely.

ssizetype
From ssizetype.U:

This variable defines ssizetype to be something like ssize_t, long or int. It is used by functions that return a count of bytes or an error condition. It must be a signed type. We will pick a type such that sizeof(SSize_t) == sizeof(Size_t).

startperl
From startperl.U:

This variable contains the string to put on the front of a perl script to make sure (hopefully) that it runs with perl and not some shell. Of course, that leading line must be followed by the classical perl idiom: eval 'exec perl -S $0 ${1+$@}' if $running_under_some_shell; to guarantee perl startup should the shell execute the script. Note that this magic incatation is not understood by csh.

startsh
From startsh.U:

This variable contains the string to put on the front of a shell script to make sure (hopefully) that it runs with sh and not some other shell.

static_ext
From Extensions.U:

This variable holds a list of XS extension files we want to link statically into the package. It is used by Makefile.

stdchar
From stdchar.U:

This variable conditionally defines STDCHAR to be the type of char used in stdio.h. It has the values ``unsigned char'' or char.

stdio_base
From d_stdstdio.U:

This variable defines how, given a FILE pointer, fp, to access the _base field (or equivalent) of stdio.h's FILE structure. This will be used to define the macro FILE_base(fp).

stdio_bufsiz
From d_stdstdio.U:

This variable defines how, given a FILE pointer, fp, to determine the number of bytes store in the I/O buffer pointer to by the _base field (or equivalent) of stdio.h's FILE structure. This will be used to define the macro FILE_bufsiz(fp).

stdio_cnt
From d_stdstdio.U:

This variable defines how, given a FILE pointer, fp, to access the _cnt field (or equivalent) of stdio.h's FILE structure. This will be used to define the macro FILE_cnt(fp).

stdio_filbuf
From d_stdstdio.U:

This variable defines how, given a FILE pointer, fp, to tell stdio to refill it's internal buffers (?). This will be used to define the macro FILE_filbuf(fp).

stdio_ptr
From d_stdstdio.U:

This variable defines how, given a FILE pointer, fp, to access the _ptr field (or equivalent) of stdio.h's FILE structure. This will be used to define the macro FILE_ptr(fp).

stdio_stream_array
From stdio_streams.U:

This variable tells the name of the array holding the stdio streams. Usual values include _iob, __iob, and __sF.

strings
From i_string.U:

This variable holds the full path of the string header that will be used. Typically /usr/include/string.h or /usr/include/strings.h.

submit
From Loc.U:

This variable is defined but not used by Configure. The value is a plain '' and is not useful.

subversion
From patchlevel.U:

The subversion level of this package. The value of subversion comes from the patchlevel.h file. In a version number such as 5.6.1, this is the 1. In patchlevel.h, this is referred to as PERL_SUBVERSION. This is unique to perl.

sysman
From sysman.U:

This variable holds the place where the manual is located on this system. It is not the place where the user wants to put his manual pages. Rather it is the place where Configure may look to find manual for unix commands (section 1 of the manual usually). See mansrc.

t

tail
From Loc.U:

This variable is defined but not used by Configure. The value is a plain '' and is not useful.

tar
From Loc.U:

This variable is defined but not used by Configure. The value is a plain '' and is not useful.

tbl
From Loc.U:

This variable is defined but not used by Configure. The value is a plain '' and is not useful.

tee
From Loc.U:

This variable is defined but not used by Configure. The value is a plain '' and is not useful.

test
From Loc.U:

This variable is used internally by Configure to determine the full pathname (if any) of the test program. After Configure runs, the value is reset to a plain test and is not useful.

timeincl
From i_time.U:

This variable holds the full path of the included time header(s).

timetype
From d_time.U:

This variable holds the type returned by time(). It can be long, or time_t on BSD sites (in which case <sys/types.h> should be included). Anyway, the type Time_t should be used.

touch
From Loc.U:

This variable is used internally by Configure to determine the full pathname (if any) of the touch program. After Configure runs, the value is reset to a plain touch and is not useful.

tr
From Loc.U:

This variable is used internally by Configure to determine the full pathname (if any) of the tr program. After Configure runs, the value is reset to a plain tr and is not useful.

trnl
From trnl.U:

This variable contains the value to be passed to the tr(1) command to transliterate a newline. Typical values are \012 and \n. This is needed for EBCDIC systems where newline is not necessarily \012.

troff
From Loc.U:

This variable is defined but not used by Configure. The value is a plain '' and is not useful.

u

u16size
From perlxv.U:

This variable is the size of an U16 in bytes.

u16type
From perlxv.U:

This variable contains the C type used for Perl's U16.

u32size
From perlxv.U:

This variable is the size of an U32 in bytes.

u32type
From perlxv.U:

This variable contains the C type used for Perl's U32.

u64size
From perlxv.U:

This variable is the size of an U64 in bytes.

u64type
From perlxv.U:

This variable contains the C type used for Perl's U64.

u8size
From perlxv.U:

This variable is the size of an U8 in bytes.

u8type
From perlxv.U:

This variable contains the C type used for Perl's U8.

uidformat
From uidf.U:

This variable contains the format string used for printing a Uid_t.

uidsign
From uidsign.U:

This variable contains the signedness of a uidtype. 1 for unsigned, -1 for signed.

uidsize
From uidsize.U:

This variable contains the size of a uidtype in bytes.

uidtype
From uidtype.U:

This variable defines Uid_t to be something like uid_t, int, ushort, or whatever type is used to declare user ids in the kernel.

uname
From Loc.U:

This variable is used internally by Configure to determine the full pathname (if any) of the uname program. After Configure runs, the value is reset to a plain uname and is not useful.

uniq
From Loc.U:

This variable is used internally by Configure to determine the full pathname (if any) of the uniq program. After Configure runs, the value is reset to a plain uniq and is not useful.

uquadtype
From quadtype.U:

This variable defines Uquad_t to be something like unsigned long, unsigned int, unsigned long long, uint64_t, or whatever type is used for 64-bit integers.

use5005threads
From usethreads.U:

This variable conditionally defines the USE_5005THREADS symbol, and indicates that Perl should be built to use the 5.005-based threading implementation.

use64bitall
From use64bits.U:

This variable conditionally defines the USE_64_BIT_ALL symbol, and indicates that 64-bit integer types should be used when available. The maximal possible 64-bitness is employed: LP64 or ILP64, meaning that you will be able to use more than 2 gigabytes of memory. This mode is even more binary incompatible than USE_64_BIT_INT. You may not be able to run the resulting executable in a 32-bit CPU at all or you may need at least to reboot your OS to 64-bit mode.

use64bitint
From use64bits.U:

This variable conditionally defines the USE_64_BIT_INT symbol, and indicates that 64-bit integer types should be used when available. The minimal possible 64-bitness is employed, just enough to get 64-bit integers into Perl. This may mean using for example ``long longs'', while your memory may still be limited to 2 gigabytes.

usedl
From dlsrc.U:

This variable indicates if the system supports dynamic loading of some sort. See also dlsrc and dlobj.

useithreads
From usethreads.U:

This variable conditionally defines the USE_ITHREADS symbol, and indicates that Perl should be built to use the interpreter-based threading implementation.

uselargefiles
From uselfs.U:

This variable conditionally defines the USE_LARGE_FILES symbol, and indicates that large file interfaces should be used when available.

uselongdouble
From uselongdbl.U:

This variable conditionally defines the USE_LONG_DOUBLE symbol, and indicates that long doubles should be used when available.

usemorebits
From usemorebits.U:

This variable conditionally defines the USE_MORE_BITS symbol, and indicates that explicit 64-bit interfaces and long doubles should be used when available.

usemultiplicity
From usemultiplicity.U:

This variable conditionally defines the MULTIPLICITY symbol, and indicates that Perl should be built to use multiplicity.

usemymalloc
From mallocsrc.U:

This variable contains y if the malloc that comes with this package is desired over the system's version of malloc. People often include special versions of malloc for effiency, but such versions are often less portable. See also mallocsrc and mallocobj. If this is y, then -lmalloc is removed from $libs.

usenm
From usenm.U:

This variable contains true or false depending whether the nm extraction is wanted or not.

useopcode
From Extensions.U:

This variable holds either true or false to indicate whether the Opcode extension should be used. The sole use for this currently is to allow an easy mechanism for users to skip the Opcode extension from the Configure command line.

useperlio
From useperlio.U:

This variable conditionally defines the USE_PERLIO symbol, and indicates that the PerlIO abstraction should be used throughout.

useposix
From Extensions.U:

This variable holds either true or false to indicate whether the POSIX extension should be used. The sole use for this currently is to allow an easy mechanism for hints files to indicate that POSIX will not compile on a particular system.

usesfio
From d_sfio.U:

This variable is set to true when the user agrees to use sfio. It is set to false when sfio is not available or when the user explicitely requests not to use sfio. It is here primarily so that command-line settings can override the auto-detection of d_sfio without running into a ``WHOA THERE''.

useshrplib
From libperl.U:

This variable is set to yes if the user wishes to build a shared libperl, and no otherwise.

usesocks
From usesocks.U:

This variable conditionally defines the USE_SOCKS symbol, and indicates that Perl should be built to use SOCKS.

usethreads
From usethreads.U:

This variable conditionally defines the USE_THREADS symbol, and indicates that Perl should be built to use threads.

usevendorprefix
From vendorprefix.U:

This variable tells whether the vendorprefix and consequently other vendor* paths are in use.

usevfork
From d_vfork.U:

This variable is set to true when the user accepts to use vfork. It is set to false when no vfork is available or when the user explicitely requests not to use vfork.

usrinc
From usrinc.U:

This variable holds the path of the include files, which is usually /usr/include. It is mainly used by other Configure units.

uuname
From Loc.U:

This variable is defined but not used by Configure. The value is a plain '' and is not useful.

uvoformat
From perlxvf.U:

This variable contains the format string used for printing a Perl UV as an unsigned octal integer.

uvsize
From perlxv.U:

This variable is the size of a UV in bytes.

uvtype
From perlxv.U:

This variable contains the C type used for Perl's UV.

uvuformat
From perlxvf.U:

This variable contains the format string used for printing a Perl UV as an unsigned decimal integer.

uvxformat
From perlxvf.U:

This variable contains the format string used for printing a Perl UV as an unsigned hexadecimal integer.

v

vendorarch
From vendorarch.U:

This variable contains the value of the PERL_VENDORARCH symbol. It may have a ~ on the front. The standard distribution will put nothing in this directory. Vendors who distribute perl may wish to place their own architecture-dependent modules and extensions in this directory with MakeMaker Makefile.PL INSTALLDIRS=vendor or equivalent. See INSTALL for details.

vendorarchexp
From vendorarch.U:

This variable is the ~name expanded version of vendorarch, so that you may use it directly in Makefiles or shell scripts.

vendorbin
From vendorbin.U:

This variable contains the eventual value of the VENDORBIN symbol. It may have a ~ on the front. The standard distribution will put nothing in this directory. Vendors who distribute perl may wish to place additional binaries in this directory with MakeMaker Makefile.PL INSTALLDIRS=vendor or equivalent. See INSTALL for details.

vendorbinexp
From vendorbin.U:

This variable is the ~name expanded version of vendorbin, so that you may use it directly in Makefiles or shell scripts.

vendorlib
From vendorlib.U:

This variable contains the eventual value of the VENDORLIB symbol, which is the name of the private library for this package. The standard distribution will put nothing in this directory. Vendors who distribute perl may wish to place their own modules in this directory with MakeMaker Makefile.PL INSTALLDIRS=vendor or equivalent. See INSTALL for details.

vendorlib_stem
From vendorlib.U:

This variable is $vendorlibexp with any trailing version-specific component removed. The elements in inc_version_list (inc_version_list.U) can be tacked onto this variable to generate a list of directories to search.

vendorlibexp
From vendorlib.U:

This variable is the ~name expanded version of vendorlib, so that you may use it directly in Makefiles or shell scripts.

vendorprefix
From vendorprefix.U:

This variable holds the full absolute path of the directory below which the vendor will install add-on packages. See INSTALL for usage and examples.

vendorprefixexp
From vendorprefix.U:

This variable holds the full absolute path of the directory below which the vendor will install add-on packages. Derived from vendorprefix.

version
From patchlevel.U:

The full version number of this package, such as 5.6.1 (or 5_6_1). This combines revision, patchlevel, and subversion to get the full version number, including any possible subversions. This is suitable for use as a directory name, and hence is filesystem dependent.

vi
From Loc.U:

This variable is defined but not used by Configure. The value is a plain '' and is not useful.

voidflags
From voidflags.U:

This variable contains the eventual value of the VOIDFLAGS symbol, which indicates how much support of the void type is given by this compiler. See VOIDFLAGS for more info.

x

xlibpth
From libpth.U:

This variable holds extra path (space-separated) used to find libraries on this platform, for example CPU-specific libraries (on multi-CPU platforms) may be listed here.

xs_apiversion
From xs_apiversion.U:

This variable contains the version of the oldest perl binary compatible with the present perl. perl.c:incpush() and lib/lib.pm will automatically search in $sitearch for older directories across major versions back to xs_apiversion. This is only useful if you have a perl library directory tree structured like the default one. See INSTALL for how this works. The versioned site_perl directory was introduced in 5.005, so that is the lowest possible value. Since this can depend on compile time options (such as bincompat) it is set by Configure. Other non-default sources of potential incompatibility, such as multiplicity, threads, debugging, 64bits, sfio, etc., are not checked for currently, though in principle we could go snooping around in old Config.pm files.

z

zcat
From Loc.U:

This variable is defined but not used by Configure. The value is a plain '' and is not useful.

zip
From Loc.U:

This variable is used internally by Configure to determine the full pathname (if any) of the zip program. After Configure runs, the value is reset to a plain zip and is not useful.


NOTE

This module contains a good example of how to use tie to implement a cache and an example of how to make a tied variable readonly to those outside of it.

 Config - access Perl configuration information