NAME

Config - access Perl configuration information

SYNOPSIS

    use Config;
    if ($Config{usethreads}) {
        print "has thread support\n"
    }

    use Config qw(myconfig config_sh config_vars config_re);

    print myconfig();

    print config_sh();

    print config_re();

    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_re($regex)

Like config_sh() but returns, as a list, only the config entries who's names match the $regex.

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 library files. 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. DJGPP, Cygwin and OS/2 use .exe. Stratus VOS uses .pm. On operating systems which do not require a specific extension for executable files, this variable is empty.

_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.

afsroot

From afs.U:

This variable is by default set to /afs. In the unlikely case this is not the correct root, it is possible to override this with a hint value or command line option. This will be used in subsequent tests for AFSness in the Perl configure and test process.

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.

perl.c:incpush() and lib/lib.pm will automatically search in $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 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 inc_version_list.U.

XXX To do: Since compatibility can depend on compile time options (such as bincompat, longlong, etc.) it should (perhaps) be set by Configure, but currently it isn't. Currently, we read a hard-wired value from patchlevel.h. Perhaps what we ought to do is take the hard-wired value from patchlevel.h but then modify it if the current Configure options warrant. 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.

archname

From archname.U:

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

archname64

From use64bits.U:

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

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.

asctime_r_proto

From d_asctime_r.U:

This variable encodes the prototype of asctime_r. It is zero if d_asctime_r is undef, and one of the REENTRANT_PROTO_T_ABC macros of reentr.h if d_asctime_r is defined.

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.

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 used internally by Configure to determine the full pathname (if any) of the bison program. After Configure runs, the value is reset to a plain bison 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 a UV. 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 and gcc. Fervent ANSI compilers may be called c89. AIX has xlc.

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.

ccflags_uselargefiles

From uselfs.U:

This variable contains the compiler flags needed by large file builds and added to ccflags by hints files.

ccname

From Checkcc.U:

This can set either by hints files or by Configure. If using gcc, this is gcc, and if not, usually equal to cc, unimpressive, no? Some platforms, however, make good use of this by storing the flavor of the C compiler being used here. For example if using the Sun WorkShop suite, ccname will be workshop.

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.

ccversion

From Checkcc.U:

This can set either by hints files or by Configure. If using a (non-gcc) vendor cc, this variable may contain a version for the compiler.

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.

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 used internally by Configure to determine the full pathname (if any) of the chmod program. After Configure runs, the value is reset to a plain chmod 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.

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 concatenation 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.

crypt_r_proto

From d_crypt_r.U:

This variable encodes the prototype of crypt_r. It is zero if d_crypt_r is undef, and one of the REENTRANT_PROTO_T_ABC macros of reentr.h if d_crypt_r is defined.

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.

ctermid_r_proto

From d_ctermid_r.U:

This variable encodes the prototype of ctermid_r. It is zero if d_ctermid_r is undef, and one of the REENTRANT_PROTO_T_ABC macros of reentr.h if d_ctermid_r is defined.

ctime_r_proto

From d_ctime_r.U:

This variable encodes the prototype of ctime_r. It is zero if d_ctime_r is undef, and one of the REENTRANT_PROTO_T_ABC macros of reentr.h if d_ctime_r is defined.

d

d__fwalk

From d__fwalk.U:

This variable conditionally defines HAS__FWALK if _fwalk() is available to apply a function to all the file handles.

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_aintl

From d_aintl.U:

This variable conditionally defines the HAS_AINTL symbol, which indicates to the C program that the aintl() routine is available. If copysignl is also present we can emulate modfl.

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_asctime_r

From d_asctime_r.U:

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

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_attribute_format

From d_attribut.U:

This variable conditionally defines HASATTRIBUTE_FORMAT, which indicates the C compiler can check for printf-like formats.

d_attribute_malloc

From d_attribut.U:

This variable conditionally defines HASATTRIBUTE_MALLOC, which indicates the C compiler can understand functions as having malloc-like semantics.

d_attribute_nonnull

From d_attribut.U:

This variable conditionally defines HASATTRIBUTE_NONNULL, which indicates that the C compiler can know that certain arguments must not be NULL, and will check accordingly at compile time.

d_attribute_noreturn

From d_attribut.U:

This variable conditionally defines HASATTRIBUTE_NORETURN, which indicates that the C compiler can know that certain functions are guaranteed never to return.

d_attribute_pure

From d_attribut.U:

This variable conditionally defines HASATTRIBUTE_PURE, which indicates that the C compiler can know that certain functions are pure functions, meaning that they have no side effects, and only rely on function input and/or global data for their results.

d_attribute_unused

From d_attribut.U:

This variable conditionally defines HASATTRIBUTE_UNUSED, which indicates that the C compiler can know that certain variables and arguments may not always be used, and to not throw warnings if they don't get used.

d_attribute_warn_unused_result

From d_attribut.U:

This variable conditionally defines HASATTRIBUTE_WARN_UNUSED_RESULT, which indicates that the C compiler can know that certain functions have a return values that must not be ignored, such as malloc() or open().

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_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_builtin_choose_expr

From d_builtin.U:

This conditionally defines HAS_BUILTIN_CHOOSE_EXPR, which indicates that the compiler supports __builtin_choose_expr(x,y,z). This built-in function is analogous to the x?y:z operator in C, except that the expression returned has its type unaltered by promotion rules. Also, the built-in function does not evaluate the expression that was not chosen.

d_builtin_expect

From d_builtin.U:

This conditionally defines HAS_BUILTIN_EXPECT, which indicates that the compiler supports __builtin_expect(exp,c). You may use __builtin_expect to provide the compiler with branch prediction information.

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_c99_variadic_macros

From d_c99_variadic.U:

This variable conditionally defines the HAS_C99_VARIADIC_MACROS symbol, which indicates to the C program that C99 variadic macros are available.

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_class

From d_class.U:

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

d_clearenv

From d_clearenv.U:

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

d_closedir

From d_closedir.U:

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

d_cmsghdr_s

From d_cmsghdr_s.U:

This variable conditionally defines the HAS_STRUCT_CMSGHDR symbol, which indicates that the struct cmsghdr is supported.

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_copysignl

From d_copysignl.U:

This variable conditionally defines the HAS_COPYSIGNL symbol, which indicates to the C program that the copysignl() routine is available. If aintl is also present we can emulate modfl.

d_cplusplus

From d_cplusplus.U:

This variable conditionally defines the USE_CPLUSPLUS symbol, which indicates that a C++ compiler was used to compiled Perl and will be used to compile extensions.

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_crypt_r

From d_crypt_r.U:

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

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_ctermid

From d_ctermid.U:

This variable conditionally defines CTERMID if ctermid() is available to generate filename for terminal.

d_ctermid_r

From d_ctermid_r.U:

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

d_ctime_r

From d_ctime_r.U:

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

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_dbminitproto

From d_dbminitproto.U:

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

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_dir_dd_fd

From d_dir_dd_fd.U:

This variable conditionally defines the HAS_DIR_DD_FD symbol, which indicates that the DIR directory stream type contains a member variable called dd_fd.

d_dirfd

From d_dirfd.U:

This variable conditionally defines the HAS_DIRFD constant, which indicates to the C program that dirfd() is available to return the file descriptor of a directory stream.

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_drand48_r

From d_drand48_r.U:

This variable conditionally defines the HAS_DRAND48_R symbol, which indicates to the C program that the drand48_r() routine is available.

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_endgrent_r

From d_endgrent_r.U:

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

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_endhostent_r

From d_endhostent_r.U:

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

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_endnetent_r

From d_endnetent_r.U:

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

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_endprotoent_r

From d_endprotoent_r.U:

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

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_endpwent_r

From d_endpwent_r.U:

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

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_endservent_r

From d_endservent_r.U:

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

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_faststdio

From d_faststdio.U:

This variable conditionally defines the HAS_FAST_STDIO symbol, which indicates to the C program that the "fast stdio" is available to manipulate the stdio buffers directly.

d_fchdir

From d_fchdir.U:

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

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_fcntl_can_lock

From d_fcntl_can_lock.U:

This variable conditionally defines the FCNTL_CAN_LOCK symbol and indicates whether file locking with fcntl() works.

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_finite

From d_finite.U:

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

d_finitel

From d_finitel.U:

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

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_flockproto

From d_flockproto.U:

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

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_fp_class

From d_fp_class.U:

This variable conditionally defines the HAS_FP_CLASS symbol, which indicates to the C program that the fp_class() 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_fpclass

From d_fpclass.U:

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

d_fpclassify

From d_fpclassify.U:

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

d_fpclassl

From d_fpclassl.U:

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

d_fpos64_t

From d_fpos64_t.U:

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

d_frexpl

From d_frexpl.U:

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

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_fsync

From d_fsync.U:

This variable conditionally defines the HAS_FSYNC symbol, which indicates to the C program that the fsync() 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_futimes

From d_futimes.U:

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

d_Gconvert

From d_gconvert.U:

This variable holds what Gconvert is defined as to convert floating point numbers into strings. By default, Configure sets this macro to use the first of gconvert, gcvt, or sprintf that pass sprintf-%g-like behaviour tests. If perl is using long doubles, the macro uses the first of the following functions that pass Configure's tests: qgcvt, sprintf (if Configure knows how to make sprintf format long doubles--see sPRIgldbl), gconvert, gcvt, and sprintf (casting to double). The gconvert_preference and gconvert_ld_preference variables can be used to alter Configure's preferences, for doubles and long doubles, respectively. If present, they contain a space-separated list of one or more of the above function names in the order they should be tried.

d_Gconvert may be set to override Configure with a platform- specific function. If this function expects a double, a different value may need to be set by the uselongdouble.cbu call-back unit so that long doubles can be formatted without loss of precision.

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_getespwnam

From d_getespwnam.U:

This variable conditionally defines HAS_GETESPWNAM if getespwnam() is available to retrieve enchanced (shadow) password entries by name.

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_getgrent_r

From d_getgrent_r.U:

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

d_getgrgid_r

From d_getgrgid_r.U:

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

d_getgrnam_r

From d_getgrnam_r.U:

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

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_gethostbyaddr_r

From d_gethostbyaddr_r.U:

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

d_gethostbyname_r

From d_gethostbyname_r.U:

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

d_gethostent_r

From d_gethostent_r.U:

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

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_getitimer

From d_getitimer.U:

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

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_getlogin_r

From d_getlogin_r.U:

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

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_getnetbyaddr_r

From d_getnetbyaddr_r.U:

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

d_getnetbyname_r

From d_getnetbyname_r.U:

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

d_getnetent_r

From d_getnetent_r.U:

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

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_getpagsz

From d_getpagsz.U:

This variable conditionally defines HAS_GETPAGESIZE if getpagesize() is available to get the system page size.

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_getpgrp

From d_getpgrp.U:

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

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_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_getprotobyname_r

From d_getprotobyname_r.U:

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

d_getprotobynumber_r

From d_getprotobynumber_r.U:

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

d_getprotoent_r

From d_getprotoent_r.U:

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

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_getprpwnam

From d_getprpwnam.U:

This variable conditionally defines HAS_GETPRPWNAM if getprpwnam() is available to retrieve protected (shadow) password entries by name.

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_getpwent_r

From d_getpwent_r.U:

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

d_getpwnam_r

From d_getpwnam_r.U:

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

d_getpwuid_r

From d_getpwuid_r.U:

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

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_getservbyname_r

From d_getservbyname_r.U:

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

d_getservbyport_r

From d_getservbyport_r.U:

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

d_getservent_r

From d_getservent_r.U:

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

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_getspnam

From d_getspnam.U:

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

d_getspnam_r

From d_getspnam_r.U:

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

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_gmtime_r

From d_gmtime_r.U:

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

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_ilogbl

From d_ilogbl.U:

This variable conditionally defines the HAS_ILOGBL symbol, which indicates to the C program that the ilogbl() routine is available. If scalbnl is also present we can emulate frexpl.

d_inc_version_list

From inc_version_list.U:

This variable conditionally defines PERL_INC_VERSION_LIST. It is set to undef when PERL_INC_VERSION_LIST is empty.

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_isfinite

From d_isfinite.U:

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

d_isinf

From d_isinf.U:

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

d_isnan

From d_isnan.U:

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

d_isnanl

From d_isnanl.U:

This variable conditionally defines the HAS_ISNANL symbol, which indicates to the C program that the isnanl() routine 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_libm_lib_version

From d_libm_lib_version.U:

This variable conditionally defines the LIBM_LIB_VERSION symbol, which indicates to the C program that math.h defines _LIB_VERSION being available in libm

d_link

From d_link.U:

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

d_localtime_r

From d_localtime_r.U:

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

d_localtime_r_needs_tzset

From d_localtime_r.U:

This variable conditionally defines the LOCALTIME_R_NEEDS_TZSET symbol, which makes us call tzset before localtime_r()

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_malloc_good_size

From d_malloc_size.U:

This symbol, if defined, indicates that the malloc_good_size routine is available for use.

d_malloc_size

From d_malloc_size.U:

This symbol, if defined, indicates that the malloc_size routine is available for use.

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_modfl

From d_modfl.U:

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

d_modfl_pow32_bug

From d_modfl.U:

This variable conditionally defines the HAS_MODFL_POW32_BUG symbol, which indicates that modfl() is broken for long doubles >= pow(2, 32). For example from 4294967303.150000 one would get 4294967302.000000 and 1.150000. The bug has been seen in certain versions of glibc, release 2.2.2 is known to be okay.

d_modflproto

From d_modfl.U:

This symbol, if defined, indicates that the system provides a prototype for the modfl() function. Otherwise, it is up to the program to supply one. C99 says it should be long double modfl(long double, long double *);

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_msghdr_s

From d_msghdr_s.U:

This variable conditionally defines the HAS_STRUCT_MSGHDR symbol, which indicates that the struct msghdr is supported.

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_nanosleep

From d_nanosleep.U:

This variable conditionally defines HAS_NANOSLEEP if nanosleep() is available to sleep with 1E-9 sec accuracy.

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_nl_langinfo

From d_nl_langinfo.U:

This variable conditionally defines the HAS_NL_LANGINFO symbol, which indicates to the C program that the nl_langinfo() 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_nv_zero_is_allbits_zero

From perlxv.U:

This variable indicates whether a variable of type nvtype stores 0.0 in memory as all bits zero.

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_perl_otherlibdirs

From otherlibdirs.U:

This variable conditionally defines PERL_OTHERLIBDIRS, which contains a colon-separated set of paths for the perl binary to include in @INC. See also otherlibdirs.

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_PRIfldbl symbol, which indiciates that stdio has a symbol to print long doubles.

d_PRIEUldbl

From longdblfio.U:

This variable conditionally defines the PERL_PRIfldbl symbol, which indiciates that stdio has a symbol to print long doubles. The U in the name is to separate this from d_PRIeldbl so that even case-blind systems can see the difference.

d_PRIfldbl

From longdblfio.U:

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

d_PRIFUldbl

From longdblfio.U:

This variable conditionally defines the PERL_PRIfldbl symbol, which indiciates that stdio has a symbol to print long doubles. The U in the name is to separate this from d_PRIfldbl so that even case-blind systems can see the difference.

d_PRIgldbl

From longdblfio.U:

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

d_PRIGUldbl

From longdblfio.U:

This variable conditionally defines the PERL_PRIfldbl symbol, which indiciates that stdio has a symbol to print long doubles. The U in the name is to separate this from d_PRIgldbl so that even case-blind systems can see the difference.

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_printf_format_null

From d_attribut.U:

This variable conditionally defines PRINTF_FORMAT_NULL_OK, which indicates the C compiler allows printf-like formats to be null.

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_PRIXU64

From quadfio.U:

This variable conditionally defines the PERL_PRIXU64 symbol, which indiciates that stdio has a symbol to print 64-bit hExADECimAl numbers. The U in the name is to separate this from d_PRIx64 so that even case-blind systems can see the difference.

d_procselfexe

From d_procselfexe.U:

Defined if $procselfexe is symlink to the absolute pathname of the executing program.

d_pseudofork

From d_vfork.U:

This variable conditionally defines the HAS_PSEUDOFORK symbol, which indicates that an emulation of the fork routine is available.

d_pthread_atfork

From d_pthread_atfork.U:

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

d_pthread_attr_setscope

From d_pthread_attr_ss.U:

This variable conditionally defines HAS_PTHREAD_ATTR_SETSCOPE if pthread_attr_setscope() is available to set the contention scope attribute of a thread attribute object.

d_pthread_yield

From d_pthread_y.U:

This variable conditionally defines the