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Config(3) - Config - access Perl configuration information - man 3 Config

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Config(3)              Perl Programmers Reference Guide              Config(3)



NAME
       Config - access(2,5) Perl configuration information

SYNOPSIS
           use Config;
           if(3,n) ($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(1,2,n) (over 900 values).

       Shell variables from the config.sh file(1,n) (written by Configure) are
       stored in(1,8) the readonly-variable %Config, indexed by their names.

       Values stored in(1,8) config.sh as 'undef' are returned as undefined values.
       The perl "exists" function can be used to check if(3,n) a named(5,8) variable
       exists.

       myconfig()
           Returns a textual summary of the major perl configuration values.
           See also "-V" in(1,8) "Switches" in(1,8) perlrun.

       config_sh()
           Returns the entire perl configuration information in(1,8) the form of
           the original config.sh shell variable assignment script.

       config_re($regex(3,7))
           Like config_sh() but returns, as a list, only the config(1,5) entries
           who's names match the $regex.

       config_vars(@names)
           Prints to STDOUT the values of the named(5,8) configuration variable.
           Each is printed on a separate line in(1,8) the form:

             name='value';

           Names which are unknown are output as "name='UNKNOWN';".  See also
           "-V:name" in(1,8) "Switches" in(1,8) perlrun.

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(1,n) ' ', $Config{sig_name};
               @sig_num{@names} = split(1,n) ' ', $Config{sig_num};
               foreach (@names) {
                   $sig_name[$sig_num{$_}] ||= $_;
               }
           }

           print "signal(2,7) #17 = $sig_name[17]\n";
           if(3,n) ($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(2,5) it.

       The Config module is installed into the architecture and version(1,3,5) spe-
       cific library directory ($Config{installarchlib}) and it checks the
       perl version(1,3,5) number when loaded.

       The values stored in(1,8) config.sh may be either single-quoted or dou-
       ble-quoted. Double-quoted strings are handy for those cases where you
       need to include escape sequences in(1,8) the strings. To avoid runtime vari-
       able interpolation, any "$" and "@" characters are replaced by "\$" and
       "\@", respectively. This isn't foolproof, of course, so don't embed
       "\$" or "\@" in(1,8) double-quoted strings unless you're willing to deal
       with the consequences. (The slashes will end up escaped and the "$" 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 plat-
       forms have custom-made "Config" variables, and may thus not have some
       of the variables described below, or may have extraneous variables spe-
       cific to that particular port.  See the port specific documentation in(1,8)
       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(7,n,1 builtins) to "true" if(3,n) "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(7,n,1 builtins) 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(1,8) subsequent
           tests for AFSness in(1,8) the Perl configure and test process.

       "alignbytes"
           From alignbytes.U:

           This variable holds the number of bytes required to align a dou-
           ble-- 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(7,n,1 builtins) if(3,n) 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(1,5) 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(1,3,5) of the oldest perl binary compatible with the
           present perl.  In a full version(1,3,5) string(3,n) such as 5.6.1, api_revision
           is the 5.  Prior to 5.5.640, the format was a floating point num-
           ber, like 5.00563.

           perl.c:incpush() and lib/lib.pm will automatically search in(1,8)
           $sitelib/.. for older directories back to the limit specified by
           these api_ variables.  This is only useful if(3,n) 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(1,8) 5.005, so that is the lowest possible value.  The
           version(1,3,5) list appropriate for the current system is determined in(1,8)
           inc_version_list.U.

           "XXX" To do:  Since compatibility can depend on compile time(1,2,n)
           options (such as bincompat, longlong, etc.) it should (perhaps) be
           set(7,n,1 builtins) by Configure, but currently it isn't.  Currently, we read(2,n,1 builtins) 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(3,n)
           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(1,3,5) of the oldest perl binary compatible with the
           present perl.  In a full version(1,3,5) string(3,n) such as 5.6.1, api_subver-
           sion 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(1,3,5) of the oldest perl binary compatible with the
           present perl.  In a full version(1,3,5) string(3,n) 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(1,8) the old-style as 5.005.  (In the 5.005_0x
           maintenance series, this was the only versioned directory in(1,8)
           $sitelib.)

       "api_versionstring"
           From patchlevel.U:

           This variable combines api_revision, api_version, and api_subver-
           sion in(1,8) 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(3,n) any) of the ar program.  After Configure runs, the
           value is reset(1,7,1 tput) to a plain "ar" and is not useful.

       "archlib"
           From archlib.U:

           This variable holds the name of the directory in(1,8) which the user
           wants to put architecture-dependent public library files for $pack-
           age.  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(1,2,n), 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 architec-
           ture.  It is used mainly to construct the default archlib.

       "archobjs"
           From Unix.U:

           This variable defines any additional objects that must be linked in(1,8)
           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(3,n)
           d_asctime_r is undef, and one of the "REENTRANT_PROTO_T_ABC" macros
           of reentr.h if(3,n) d_asctime_r is defined.

       "awk"
           From Loc.U:

           This variable is used internally by Configure to determine the full
           pathname (if(3,n) any) of the awk program.  After Configure runs, the
           value is reset(1,7,1 tput) 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(1,8) which the user
           wants to put publicly executable images for the package in(1,8) ques-
           tion.  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(1,2,n), for use in(1,8) your makefiles.

       "bison"
           From Loc.U:

           This variable is used internally by Configure to determine the full
           pathname (if(3,n) any) of the bison program.  After Configure runs, the
           value is reset(1,7,1 tput) 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(3,n) any) of the byacc program.  After Configure runs, the
           value is reset(1,7,1 tput) to a plain "byacc" and is not useful.

       "byteorder"
           From byteorder.U:

           This variable holds the byte order in(1,8) 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(3,n) if(3,n) that is what causes the
           echo(1,3x,1 builtins) command to suppress newline.  Otherwise it is null.  Correct
           usage is $echo(1,3x,1 builtins) $n "prompt for a question: $c".

       "castflags"
           From d_castneg.U:

           This variable contains a flag that precise difficulties the com-
           piler 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(1,8) argument expression list

       "cat"
           From Loc.U:

           This variable is used internally by Configure to determine the full
           pathname (if(3,n) any) of the cat program.  After Configure runs, the
           value is reset(1,7,1 tput) 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(1,2) 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(1,n)
           builds and added to ccflags by hints files.

       "ccname"
           From Checkcc.U:

           This can set(7,n,1 builtins) either by hints files or by Configure.  If using gcc,
           this is gcc, and if(3,n) not, usually equal to cc, unimpressive, no?
           Some platforms, however, make good use of this by storing the fla-
           vor of the C compiler being used here.  For example if(3,n) 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(1,8)
           this list, see cppsymbols and cppccsymbols.  The list is a space-
           separated list of symbol=value tokens.

       "ccversion"
           From Checkcc.U:

           This can set(7,n,1 builtins) either by hints files or by Configure.  If using a
           (non-gcc) vendor cc, this variable may contain a version(1,3,5) 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(1,8) address of the person who ran Configure. This can
           be used by units(1,7) 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(1,n)
           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(1,8) 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(1,2)"
           From Loc.U:

           This variable is used internally by Configure to determine the full
           pathname (if(3,n) any) of the chmod(1,2) program.  After Configure runs, the
           value is reset(1,7,1 tput) to a plain "chmod(1,2)" and is not useful.

       "chown(1,2)"
           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(1,8) 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(3,n) any) of the comm program.  After Configure runs, the
           value is reset(1,7,1 tput) 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 sys-
           tems it is a grep followed by a cat followed by a test.  This vari-
           able 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(3,n) any) of the cp program.  After Configure runs, the
           value is reset(1,7,1 tput) 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(3,n) any) of the cpp program.  After Configure runs, the
           value is reset(1,7,1 tput) to a plain "cpp" and is not useful.

       "cpp_stuff"
           From cpp_stuff.U:

           This variable contains an identification of the concatenation mech-
           anism 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(1,8) 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(3,n) which will
           invoke the C preprocessor on the standard input and produce to
           standard output.  This variable will have the value "-" if(3,n) 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 preproces-
           sor on standard input and put the output to stdout. It is guaran-
           teed not to be a wrapper and may be a null string(3,n) if(3,n) no preproces-
           sor can be made directly available. This preprocessor might be dif-
           ferent 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 pre-
           processor on standard input and put the output to stdout.  It is
           primarily used by other Configure units(1,7) 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(1,8) 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(3,n)
           d_crypt_r is undef, and one of the "REENTRANT_PROTO_T_ABC" macros
           of reentr.h if(3,n) d_crypt_r is defined.

       "cryptlib"
           From d_crypt.U:

           This variable holds -lcrypt or the path to a libcrypt.a archive if(3,n)
           the crypt() function is not defined in(1,8) 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(3,n) any) of the csh program.  After Configure runs, the
           value is reset(1,7,1 tput) 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(3,n)
           d_ctermid_r is undef, and one of the "REENTRANT_PROTO_T_ABC" macros
           of reentr.h if(3,n) 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(3,n)
           d_ctime_r is undef, and one of the "REENTRANT_PROTO_T_ABC" macros
           of reentr.h if(3,n) d_ctime_r is defined.

       d


       "d__fwalk"
           From d__fwalk.U:

           This variable conditionally defines "HAS__FWALK" if(3,n) _fwalk() is
           available to apply a function to all the file(1,n) handles.

       "d_access"
           From d_access.U:

           This variable conditionally defines "HAS_ACCESS" if(3,n) the access(2,5)()
           system call is available to check for access(2,5) 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(1,2)() 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(7,n,1 builtins) 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_attribut"
           From d_attribut.U:

           This variable conditionally defines "HASATTRIBUTE", which indicates
           the C compiler can check for function attributes, such as printf(1,3,1 builtins)
           formats.

       "d_bcmp"
           From d_bcmp.U:

           This variable conditionally defines the "HAS_BCMP" symbol if(3,n) the
           bcmp() routine is available to compare strings.

       "d_bcopy"
           From d_bcopy.U:

           This variable conditionally defines the "HAS_BCOPY" symbol if(3,n) 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(3,n) getpgrp
           needs one arguments whereas "USG" one needs none.

       "d_bsdsetpgrp"
           From d_setpgrp.U:

           This variable conditionally defines "USE_BSD_SETPGRP" if(3,n) 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(3,n) the
           bzero() routine is available to set(7,n,1 builtins) 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(3,n) 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(1,2)() 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(1,2)() 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(2,7) 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_closedir"
           From d_closedir.U:

           This variable conditionally defines "HAS_CLOSEDIR" if(3,n) closedir() is
           available.

       "d_cmsghdr_s"
           From d_cmsghdr_s.U:

           This variable conditionally defines the "HAS_STRUCT_CMSGHDR" sym-
           bol, 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_crypt"
           From d_crypt.U:

           This variable conditionally defines the "CRYPT" symbol, which indi-
           cates 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 indi-
           cates to the C program that the C-shell exists.

       "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(1,3,5) names.

       "d_dbl_dig"
           From d_dbl_dig.U:

           This variable conditionally defines d_dbl_dig if(3,n) this system's
           header files provide "DBL_DIG", which is the number of significant
           digits in(1,8) 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 proto-
           type for the dbminit() function.  Otherwise, it is up to the pro-
           gram 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_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(1,n) 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 avail-
           able.

       "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 proto-
           type for the drand48() function.  Otherwise, it is up to the pro-
           gram to supply one.

       "d_dup2"
           From d_dup2.U:

           This variable conditionally defines HAS_DUP2 if(3,n) dup2() is available
           to duplicate file(1,n) 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(2,5) 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(3,n) endhos-
           tent() is available to close(2,7,n) whatever was being used for host(1,5)
           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(3,n) endnetent()
           is available to close(2,7,n) 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(3,n) endpro-
           toent() is available to close(2,7,n) 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(2,5) of the passwd(1,5) 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(3,n) endser-
           vent() is available to close(2,7,n) 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(3,n) "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(1,n) 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(3,n) 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" sym-
           bol, which indicates if(3,n) 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(3,n) 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(3,n) fgetpos() is
           available to get the file(1,n) 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(3,n) flock(1,2)() is
           available to do file(1,n) 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 proto-
           type for the flock(1,2)() 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 asso-
           ciated with a given open(2,3,n) file(1,n) 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(3,n) 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" sym-
           bol, 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(3,n) fsetpos() is
           available to set(7,n,1 builtins) the file(1,n) 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_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 Con-
           figure's tests: qgcvt, sprintf (if(3,n) Configure knows how to make
           sprintf format long doubles--see sPRIgldbl), gconvert, gcvt, and
           sprintf (casting to double).  The gconvert_preference and gcon-
           vert_ld_preference variables can be used to alter Configure's pref-
           erences, for doubles and long doubles, respectively.  If present,
           they contain a space-separated list of one or more of the above
           function names in(1,8) the order they should be tried.

           d_Gconvert may be set(7,n,1 builtins) to override Configure with a platform- spe-
           cific function.  If this function expects a double, a different
           value may need to be set(7,n,1 builtins) 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(3,n) getespw-
           nam() is available to retrieve enchanced (shadow(3,5)) 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(2,5) 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(1,8,3 Search::Dict) 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(1,8,3 Search::Dict) up host(1,5) names in(1,8) some data base or other.

       "d_gethent"
           From d_gethent.U:

           This variable conditionally defines "HAS_GETHOSTENT" if(3,n) gethos-
           tent() is available to look(1,8,3 Search::Dict) up host(1,5) names in(1,8) 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(1,5) name.

       "d_gethostbyaddr_r"
           From d_gethostbyaddr_r.U:

           This variable conditionally defines the "HAS_GETHOSTBYADDR_R" sym-
           bol, 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" sym-
           bol, 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" sym-
           bol, which indicates to the C program that <netdb.h> supplies pro-
           totypes 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(1,3,5) 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(2,8) info(1,5,n) 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(2,8) 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(1,8,3 Search::Dict) 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(1,8,3 Search::Dict) up networks by their names.

       "d_getnent"
           From d_getnent.U:

           This variable conditionally defines "HAS_GETNETENT" if(3,n) getnetent()
           is available to look(1,8,3 Search::Dict) up network names in(1,8) some data base or another.

       "d_getnetbyaddr_r"
           From d_getnetbyaddr_r.U:

           This variable conditionally defines the "HAS_GETNETBYADDR_R" sym-
           bol, 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" sym-
           bol, 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(3,n) getpage-
           size() is available to get the system page size.

       "d_getpbyname"
           From d_getprotby.U:

           This variable conditionally defines the "HAS_GETPROTOBYNAME" sym-
           bol, which indicates to the C program that the getprotobyname()
           routine is available to look(1,8,3 Search::Dict) up protocols by their name.

       "d_getpbynumber"
           From d_getprotby.U:

           This variable conditionally defines the "HAS_GETPROTOBYNUMBER" sym-
           bol, which indicates to the C program that the getprotobynumber()
           routine is available to look(1,8,3 Search::Dict) up protocols by their number.

       "d_getpent"
           From d_getpent.U:

           This variable conditionally defines "HAS_GETPROTOENT" if(3,n) getpro-
           toent() is available to look(1,8,3 Search::Dict) up protocols in(1,8) 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 avail-
           able 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(1,8) DG/"UX") rou-
           tine is available to get the current process group.

       "d_getpgrp"
           From d_getpgrp.U:

           This variable conditionally defines "HAS_GETPGRP" if(3,n) 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(3,n) getprior-
           ity() is available to get a process's priority.

       "d_getprotobyname_r"
           From d_getprotobyname_r.U:

           This variable conditionally defines the "HAS_GETPROTOBYNAME_R" sym-
           bol, 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 getprotobynum-
           ber_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" sym-
           bol, which indicates to the C program that <netdb.h> supplies pro-
           totypes for the various getproto*() functions.  See also netdb-
           type.U for probing for various netdb types.

       "d_getprpwnam"
           From d_getprpwnam.U:

           This variable conditionally defines "HAS_GETPRPWNAM" if(3,n) getprpw-
           nam() is available to retrieve protected (shadow(3,5)) 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(2,5) of the passwd(1,5) 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(1,8,3 Search::Dict) 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(1,8,3 Search::Dict) up services by their port.

       "d_getsent"
           From d_getsent.U:

           This variable conditionally defines "HAS_GETSERVENT" if(3,n) getser-
           vent() is available to look(1,8,3 Search::Dict) up network services in(1,8) some data base
           or another.

       "d_getservbyname_r"
           From d_getservbyname_r.U:

           This variable conditionally defines the "HAS_GETSERVBYNAME_R" sym-
           bol, 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" sym-
           bol, 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" sym-
           bol, which indicates to the C program that <netdb.h> supplies pro-
           totypes 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(3,n) getspnam() is
           available to retrieve SysV shadow(3,5) 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(3,n)). 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(3,n) 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(1,8) <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(2,8) options of file(1,n) systems.

       "d_htonl"
           From d_htonl.U:

           This variable conditionally defines "HAS_HTONL" if(3,n) 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_index"
           From d_strchr.U:

           This variable conditionally defines "HAS_INDEX" if(3,n) index() and
           rindex() are available for string(3,n) 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(3,n) 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(2,3)() routine is available
           to kill(1,2,1 builtins) 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(1,2) (instead of following the link(1,2)).

       "d_ldbl_dig"
           From d_ldbl_dig.U:

           This variable conditionally defines d_ldbl_dig if(3,n) this system's
           header files provide "LDBL_DIG", which is the number of significant
           digits in(1,8) a long double precision number.

       "d_link"
           From d_link.U:

           This variable conditionally defines "HAS_LINK" if(3,n) link(1,2)() is avail-
           able 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_locconv"
           From d_locconv.U:

           This variable conditionally defines "HAS_LOCALECONV" if(3,n) locale-
           conv() is available for numeric and monetary formatting conven-
           tions.

       "d_lockf"
           From d_lockf.U:

           This variable conditionally defines "HAS_LOCKF" if(3,n) lockf() is
           available to do file(1,n) locking.

       "d_longdbl"
           From d_longdbl.U:

           This variable conditionally defines "HAS_LONG_DOUBLE" if(3,n) the long
           double type is supported.

       "d_longlong"
           From d_longlong.U:

           This variable conditionally defines "HAS_LONG_LONG" if(3,n) 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 proto-
           type 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(3,n) lstat() is
           available to do file(1,n) stats on symbolic links.

       "d_madvise"
           From d_madvise.U:

           This variable conditionally defines "HAS_MADVISE" if(3,n) madvise() is
           available to map a file(1,n) 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(1,8) 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(3,n) 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(7,n,1 builtins) 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(1,2)() 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(5,8) 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(1,3)() 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(2,3,n) a uniquely named(5,8) 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(2,3,n) a uniquely named(5,8) (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(3,n) mmap() is avail-
           able to map a file(1,n) 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(1,8) certain
           versions of glibc, release 2.2.2 is known to be okay.

       "d_modflproto"
           From d_modfl.U:

           This symbol, if(3,n) defined, indicates that the system provides a pro-
           totype for the modfl() function.  Otherwise, it is up to the pro-
           gram 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(3,n) mprotect() is
           available to modify the access(2,5) 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(3,n) msync() is
           available to synchronize a mapped file.

       "d_munmap"
           From d_munmap.U:

           This variable conditionally defines "HAS_MUNMAP" if(3,n) munmap() is
           available to unmap a region mapped by mmap().

       "d_mymalloc"
           From mallocsrc.U:

           This variable conditionally defines "MYMALLOC" in(1,8) case other parts
           of the source want to take special action if(3,n) "MYMALLOC" is used.
           This may include different sorts of profiling or error(8,n) detection.

       "d_nanosleep"
           From d_nanosleep.U:

           This variable conditionally defines "HAS_NANOSLEEP" if(3,n) nanosleep()
           is available to sleep(1,3) 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(1,2)() 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 pre-
           serve all the bits a variable of type uvtype.

       "d_off64_t"
           From d_off64_t.U:

           This symbol will be defined if(3,n) the C compiler supports off64_t.

       "d_old_pthread_create_joinable"
           From d_pthrattrj.U:

           This variable conditionally defines pthread_create_joinable.  undef
           if(3,n) 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(3,n)
           usethreads is set.

       "d_oldsock"
           From d_socket.U:

           This variable conditionally defines the "OLDSOCKET" symbol, which
           indicates that the "BSD" socket(2,7,n) interface is based on 4.1c and not
           4.2.

       "d_open3"
           From d_open3.U:

           This variable conditionally defines the HAS_OPEN3 manifest con-
           stant, which indicates to the C program that the 3 argument version(1,3,5)
           of the open(2,3,n)(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 asso-
           ciated 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(2,7) is received.

       "d_perl_otherlibdirs"
           From otherlibdirs.U:

           This variable conditionally defines "PERL_OTHERLIBDIRS", which con-
           tains a colon-separated set(7,n,1 builtins) of paths for the perl binary to include
           in(1,8) @"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(1,5) name.

       "d_pipe"
           From d_pipe.U:

           This variable conditionally defines the "HAS_PIPE" symbol, which
           indicates to the C program that the pipe(2,8)() 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(1,n) 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(1,8) 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(1,8) 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(1,8) 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_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 num-
           bers.

       "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 num-
           bers.  The "U" in(1,8) 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(3,n) $procselfexe is symlink to the absolute pathname of the
           executing program.

       "d_pthread_atfork"
           From d_pthread_atfork.U:

           This variable conditionally defines the "HAS_PTHREAD_ATFORK" sym-
           bol, 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(3,n)
           pthread_attr_setscope() is available to set(7,n,1 builtins) the contention scope
           attribute of a thread attribute object.

       "d_pthread_yield"
           From d_pthread_y.U:

           This variable conditionally defines the "HAS_PTHREAD_YIELD" symbol
           if(3,n) 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(1,5) contains pw_age.

       "d_pwchange"
           From i_pwd.U:

           This variable conditionally defines "PWCHANGE", which indicates
           that struct passwd(1,5) contains pw_change.

       "d_pwclass"
           From i_pwd.U:

           This variable conditionally defines "PWCLASS", which indicates that
           struct passwd(1,5) contains pw_class.

       "d_pwcomment"
           From i_pwd.U:

           This variable conditionally defines "PWCOMMENT", which indicates
           that struct passwd(1,5) contains pw_comment.

       "d_pwexpire"
           From i_pwd.U:

           This variable conditionally defines "PWEXPIRE", which indicates
           that struct passwd(1,5) contains pw_expire.

       "d_pwgecos"
           From i_pwd.U:

           This variable conditionally defines "PWGECOS", which indicates that
           struct passwd(1,5) contains pw_gecos.

       "d_pwpasswd"
           From i_pwd.U:

           This variable conditionally defines "PWPASSWD", which indicates
           that struct passwd(1,5) contains pw_passwd.

       "d_pwquota"
           From i_pwd.U:

           This variable conditionally defines "PWQUOTA", which indicates that
           struct passwd(1,5) 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(3,n) defined, tells that there's a 64-bit integer
           type, quadtype.

       "d_random_r"
           From d_random_r.U:

           This variable conditionally defines the "HAS_RANDOM_R" symbol,
           which indicates to the C program that the random_r() routine is
           available.

       "d_readdir64_r"
           From d_readdir64_r.U:

           This variable conditionally defines the HAS_READDIR64_R symbol,
           which indicates to the C program that the readdir64_r() routine is
           available.

       "d_readdir"
           From d_readdir.U:

           This variable conditionally defines "HAS_READDIR" if(3,n) readdir(2,3)() is
           available to read(2,n,1 builtins) directory entries.

       "d_readdir_r"
           From d_readdir_r.U:

           This variable conditionally defines the "HAS_READDIR_R" symbol,
           which indicates to the C program that the readdir_r() routine is
           available.

       "d_readlink"
           From d_readlink.U:

           This variable conditionally defines the "HAS_READLINK" symbol,
           which indicates to the C program that the readlink(1,2)() routine is
           available to read(2,n,1 builtins) the value of a symbolic link.

       "d_readv"
           From d_readv.U:

           This variable conditionally defines the "HAS_READV" symbol, which
           indicates to the C program that the readv() routine is available.

       "d_recvmsg"
           From d_recvmsg.U:

           This variable conditionally defines the "HAS_RECVMSG" symbol, which
           indicates to the C program that the recvmsg() routine is available.

       "d_rename"
           From d_rename.U:

           This variable conditionally defines the "HAS_RENAME" symbol, which
           indicates to the C program that the rename(1,2,n)() routine is available
           to rename(1,2,n) files.

       "d_rewinddir"
           From d_readdir.U:

           This variable conditionally defines "HAS_REWINDDIR" if(3,n) rewinddir()
           is available.

       "d_rmdir"
           From d_rmdir.U:

           This variable conditionally defines "HAS_RMDIR" if(3,n) rmdir(1,2)() is
           available to remove directories.

       "d_safebcpy"
           From d_safebcpy.U:

           This variable conditionally defines the "HAS_SAFE_BCOPY" symbol if(3,n)
           the bcopy() routine can do overlapping copies.  Normally, you
           should probably use memmove().

       "d_safemcpy"
           From d_safemcpy.U:

           This variable conditionally defines the "HAS_SAFE_MEMCPY" symbol if(3,n)
           the memcpy() routine can do overlapping copies.  For overlapping
           copies, memmove() should be used, if(3,n) available.

       "d_sanemcmp"
           From d_sanemcmp.U:

           This variable conditionally defines the "HAS_SANE_MEMCMP" symbol if(3,n)
           the memcpy() routine is available and can be used to compare rela-
           tive magnitudes of chars with their high bits set.

       "d_sbrkproto"
           From d_sbrkproto.U:

           This variable conditionally defines the "HAS_SBRK_PROTO" symbol,
           which indicates to the C program that the system provides a proto-
           type for the sbrk() function.  Otherwise, it is up to the program
           to supply one.

       "d_scalbnl"
           From d_scalbnl.U:

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

       "d_sched_yield"
           From d_pthread_y.U:

           This variable conditionally defines the "HAS_SCHED_YIELD" symbol if(3,n)
           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_SCNfldbl"
           From longdblfio.U:

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

       "d_seekdir"
           From d_readdir.U:

           This variable conditionally defines "HAS_SEEKDIR" if(3,n) seekdir() is
           available.

       "d_select"
           From d_select.U:

           This variable conditionally defines "HAS_SELECT" if(3,n) select(2,7,2 select_tut)() is
           available to select(2,7,2 select_tut) active file(1,n) descriptors. A <sys/time.h> inclu-
           sion may be necessary for the timeout(1,3x,3x cbreak) 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 indi-
           cates 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_sendmsg"
           From d_sendmsg.U:

           This variable conditionally defines the "HAS_SENDMSG" symbol, which
           indicates to the C program that the sendmsg() 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(2,5) to the group database.

       "d_setgrent_r"
           From d_setgrent_r.U:

           This variable conditionally defines the "HAS_SETGRENT_R" symbol,
           which indicates to the C program that the setgrent_r() routine is
           available.

       "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(7,n,1 builtins) the list of process groups.

       "d_sethent"
           From d_sethent.U:

           This variable conditionally defines "HAS_SETHOSTENT" if(3,n) sethos-
           tent() is available.

       "d_sethostent_r"
           From d_sethostent_r.U:

           This variable conditionally defines the "HAS_SETHOSTENT_R" symbol,
           which indicates to the C program that the sethostent_r() routine is
           available.

       "d_setitimer"
           From d_setitimer.U:

           This variable conditionally defines the "HAS_SETITIMER" symbol,
           which indicates to the C program that the setitimer() routine 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(3,n) setlocale()
           is available to handle locale-specific ctype implementations.

       "d_setlocale_r"
           From d_setlocale_r.U:

           This variable conditionally defines the "HAS_SETLOCALE_R" symbol,
           which indicates to the C program that the setlocale_r() routine is
           available.

       "d_setnent"
           From d_setnent.U:

           This variable conditionally defines "HAS_SETNETENT" if(3,n) setnetent()
           is available.

       "d_setnetent_r"
           From d_setnetent_r.U:

           This variable conditionally defines the "HAS_SETNETENT_R" symbol,
           which indicates to the C program that the setnetent_r() routine is
           available.

       "d_setpent"
           From d_setpent.U:

           This variable conditionally defines "HAS_SETPROTOENT" if(3,n) setpro-
           toent() is available.

       "d_setpgid"
           From d_setpgid.U:

           This variable conditionally defines the "HAS_SETPGID" symbol if(3,n) the
           setpgid(pid, gpid) function is available to set(7,n,1 builtins) 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(1,8) DG/"UX") rou-
           tine is available to set(7,n,1 builtins) the current process group.

       "d_setpgrp"
           From d_setpgrp.U:

           This variable conditionally defines "HAS_SETPGRP" if(3,n) setpgrp() is
           available to set(7,n,1 builtins) the current process group.

       "d_setprior"
           From d_setprior.U:

           This variable conditionally defines "HAS_SETPRIORITY" if(3,n) setprior-
           ity() is available to set(7,n,1 builtins) a process's priority.

       "d_setproctitle"
           From d_setproctitle.U:

           This variable conditionally defines the "HAS_SETPROCTITLE" symbol,
           which indicates to the C program that the setproctitle() routine is
           available.

       "d_setprotoent_r"
           From d_setprotoent_r.U:

           This variable conditionally defines the "HAS_SETPROTOENT_R" symbol,
           which indicates to the C program that the setprotoent_r() routine
           is available.

       "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(2,5) to the passwd(1,5) data-
           base.

       "d_setpwent_r"
           From d_setpwent_r.U:

           This variable conditionally defines the "HAS_SETPWENT_R" symbol,
           which indicates to the C program that the setpwent_r() routine is
           available.

       "d_setregid"
           From d_setregid.U:

           This variable conditionally defines "HAS_SETREGID" if(3,n) 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(3,n) 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(3,n) 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(3,n) 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(3,n) setser-
           vent() is available.

       "d_setservent_r"
           From d_setservent_r.U:

           This variable conditionally defines the "HAS_SETSERVENT_R" symbol,
           which indicates to the C program that the setservent_r() routine is
           available.

       "d_setsid"
           From d_setsid.U:

           This variable conditionally defines "HAS_SETSID" if(3,n) setsid(2,8)() is
           available to set(7,n,1 builtins) the process group "ID".

       "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(2,3,n) 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" sym-
           bol, 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_sigprocmask"
           From d_sigprocmask.U:

           This variable conditionally defines "HAS_SIGPROCMASK" if(3,n) sigproc-
           mask() is available to examine or change the signal(2,7) mask of the
           calling process.

       "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(2,7) mask.

       "d_sockatmark"
           From d_sockatmark.U:

           This variable conditionally defines the "HAS_SOCKATMARK" symbol,
           which indicates to the C program that the sockatmark() routine is
           available.

       "d_sockatmarkproto"
           From d_sockatmarkproto.U:

           This variable conditionally defines the "HAS_SOCKATMARK_PROTO" sym-
           bol, which indicates to the C program that the system provides a
           prototype for the sockatmark() function.  Otherwise, it is up to
           the program to supply one.

       "d_socket"
           From d_socket.U:

           This variable conditionally defines "HAS_SOCKET", which indicates
           that the "BSD" socket(2,7,n) interface is supported.

       "d_socklen_t"
           From d_socklen_t.U:

           This symbol will be defined if(3,n) 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_socks5_init"
           From d_socks5_init.U:

           This variable conditionally defines the HAS_SOCKS5_INIT symbol,
           which indicates to the C program that the socks5_init() routine is
           available.

       "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_srand48_r"
           From d_srand48_r.U:

           This variable conditionally defines the HAS_SRAND48_R symbol, which
           indicates to the C program that the srand48_r() routine is avail-
           able.

       "d_srandom_r"
           From d_srandom_r.U:

           This variable conditionally defines the "HAS_SRANDOM_R" symbol,
           which indicates to the C program that the srandom_r() routine is
           available.

       "d_sresgproto"
           From d_sresgproto.U:

           This variable conditionally defines the "HAS_SETRESGID_PROTO" sym-
           bol, which indicates to the C program that the system provides a
           prototype for the setresgid() function.  Otherwise, it is up to the
           program to supply one.

       "d_sresuproto"
           From d_sresuproto.U:

           This variable conditionally defines the "HAS_SETRESUID_PROTO" sym-
           bol, which indicates to the C program that the system provides a
           prototype for the setresuid() function.  Otherwise, it is up to the
           program to supply one.

       "d_statblks"
           From d_statblks.U:

           This variable conditionally defines "USE_STAT_BLOCKS" if(3,n) this sys-
           tem has a stat(1,2) 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(3,n) 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(3,n) the
           "FILE_ptr" macro can be used as an lvalue.

       "d_stdio_ptr_lval_nochange_cnt"
           From d_stdstdio.U:

           This symbol is defined if(3,n) using the "FILE_ptr" macro as an lvalue
           to increase the pointer by n leaves File_cnt(fp) unchanged.

       "d_stdio_ptr_lval_sets_cnt"
           From d_stdstdio.U:

           This symbol is defined if(3,n) using the "FILE_ptr" macro as an lvalue
           to increase the pointer by n has the side effect of decreasing the
           value of File_cnt(fp) by n.

       "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(3,n) this system
           has a "FILE" structure declaring a usable _base field (or equiva-
           lent) in(1,8) stdio.h.

       "d_stdstdio"
           From d_stdstdio.U:

           This variable conditionally defines "USE_STDIO_PTR" if(3,n) this system
           has a "FILE" structure declaring usable _ptr and _cnt fields (or
           equivalent) in(1,8) stdio.h.

       "d_strchr"
           From d_strchr.U:

           This variable conditionally defines "HAS_STRCHR" if(3,n) strchr() and
           strrchr() are available for string(3,n) searching.

       "d_strcoll"
           From d_strcoll.U:

           This variable conditionally defines "HAS_STRCOLL" if(3,n) 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(8,n) code condition into an error(8,n) message string. It could be
           "strerror" or a more "complex" macro emulating strrror with
           sys_errlist[], or the "unknown" string(3,n) when both strerror and
           sys_errlist are missing.

       "d_strerror"
           From d_strerror.U:

           This variable conditionally defines "HAS_STRERROR" if(3,n) strerror() is
           available to translate error(8,n) numbers to strings.

       "d_strerror_r"
           From d_strerror_r.U:

           This variable conditionally defines the "HAS_STRERROR_R" symbol,
           which indicates to the C program that the strerror_r() routine is
           available.

       "d_strftime"
           From d_strftime.U:

           This variable conditionally defines the "HAS_STRFTIME" symbol,
           which indicates to the C program that the strftime() routine is
           available.

       "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(3,n) 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(3,n) 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_strtoq"
           From d_strtoq.U:

           This variable conditionally defines the "HAS_STRTOQ" symbol, which
           indicates to the C program that the strtoq() 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(3,n) strxfrm() is
           available to transform strings.

       "d_suidsafe"
           From d_dosuid.U:

           This variable conditionally defines "SETUID_SCRIPTS_ARE_SECURE_NOW"
           if(3,n) setuid scripts can be secure.  This test looks in(1,8) /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(3,n) syscall() is
           available call arbitrary system calls.

       "d_syscallproto"
           From d_syscallproto.U:

           This variable conditionally defines the "HAS_SYSCALL_PROTO" symbol,
           which indicates to the C program that the system provides a proto-
           type for the syscall() function.  Otherwise, it is up to the pro-
           gram to supply one.

       "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(3,n)
           sys_errnolist[] is available to translate error(8,n) numbers to the sym-
           bolic name.

       "d_syserrlst"
           From d_strerror.U:

           This variable conditionally defines "HAS_SYS_ERRLIST" if(3,n)
           sys_errlist[] is available to translate error(8,n) numbers to strings.

       "d_system"
           From d_system.U:

           This variable conditionally defines "HAS_SYSTEM" if(3,n) 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(7,n,1 builtins) foreground process group "ID".

       "d_telldir"
           From d_readdir.U:

           This variable conditionally defines "HAS_TELLDIR" if(3,n) 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 proto-
           type for the telldir() function.  Otherwise, it is up to the pro-
           gram to supply one.

       "d_time"
           From d_time.U:

           This variable conditionally defines the "HAS_TIME" symbol, which
           indicates that the time(1,2,n)() routine exists.  The time(1,2,n)() 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_tm_tm_gmtoff"
           From i_time.U:

           This variable conditionally defines "HAS_TM_TM_GMTOFF", which indi-
           cates indicates to the C program that the struct tm has the
           tm_gmtoff field.

       "d_tm_tm_zone"
           From i_time.U:

           This variable conditionally defines "HAS_TM_TM_ZONE", which indi-
           cates indicates to the C program that the struct tm has the tm_zone
           field.

       "d_tmpnam_r"
           From d_tmpnam_r.U:

           This variable conditionally defines the "HAS_TMPNAM_R" symbol,
           which indicates to the C program that the tmpnam_r() routine is
           available.

       "d_truncate"
           From d_truncate.U:

           This variable conditionally defines "HAS_TRUNCATE" if(3,n) truncate(2,7)() is
           available to truncate(2,7) files.

       "d_ttyname_r"
           From d_ttyname_r.U:

           This variable conditionally defines the "HAS_TTYNAME_R" symbol,
           which indicates to the C program that the ttyname_r() routine is
           available.

       "d_tzname"
           From d_tzname.U:

           This variable conditionally defines "HAS_TZNAME" if(3,n) tzname[] is
           available to access(2,5) timezone names.

       "d_u32align"
           From d_u32align.U:

           This variable tells whether you must access(2,5) character data through
           U32-aligned pointers.

       "d_ualarm"
           From d_ualarm.U:

           This variable conditionally defines the "HAS_UALARM" symbol, which
           indicates to the C program that the ualarm() routine is available.

       "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(7,n,1 builtins) and get the value of the file(1,n) 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(1,2)() routine may be used to
           derive the host(1,5) name.

       "d_union_semun"
           From d_union_semun.U:

           This variable conditionally defines "HAS_UNION_SEMUN" if(3,n) the union
           semun is defined by including <sys/sem.h>.

       "d_unordered"
           From d_unordered.U:

           This variable conditionally defines the "HAS_UNORDERED" symbol,
           which indicates to the C program that the unordered() routine is
           available.

       "d_usleep"
           From d_usleep.U:

           This variable conditionally defines "HAS_USLEEP" if(3,n) usleep() is
           available to do high granularity sleeps.

       "d_usleepproto"
           From d_usleepproto.U:

           This variable conditionally defines the "HAS_USLEEP_PROTO" symbol,
           which indicates to the C program that the system provides a proto-
           type for the usleep() function.  Otherwise, it is up to the program
           to supply one.

       "d_ustat"
           From d_ustat.U:

           This variable conditionally defines "HAS_USTAT" if(3,n) ustat() is
           available to query file(1,n) 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_vendorscript"
           From vendorscript.U:

           This variable conditionally defines "PERL_VENDORSCRIPT".

       "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(3,n) closedir()
           does not return a value.

       "d_voidsig"
           From d_voidsig.U:

           This variable conditionally defines "VOIDSIG" if(3,n) this system
           declares "void (*signal(2,7)(...))()" in(1,8) signal.h.  The old way was to
           declare it as "int (*signal(2,7)(...))()".

       "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(1,4) asso-
           ciation.  Otherwise (on "USG" probably), it is enough to close(2,7,n) the
           standard file(1,n) 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(1,3,1 builtins) 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(3,n) 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_writev"
           From d_writev.U:

           This variable conditionally defines the "HAS_WRITEV" symbol, which
           indicates to the C program that the writev() routine is available.

       "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(3,n) any) of the date program.  After Configure runs, the
           value is reset(1,7,1 tput) 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(1,8)
           the <db.h> header file.  In older versions of "DB", it was int,
           while in(1,8) newer ones it is u_int32_t.

       "db_prefixtype"
           From i_db.U:

           This variable contains the type of the prefix structure element in(1,8)
           the <db.h> header file.  In older versions of "DB", it was int,
           while in(1,8) newer ones it is size_t.

       "db_version_major"
           From i_db.U:

           This variable contains the major version(1,3,5) number of Berkeley "DB"
           found in(1,8) the <db.h> header file.

       "db_version_minor"
           From i_db.U:

           This variable contains the minor version(1,3,5) number of Berkeley "DB"
           found in(1,8) the <db.h> header file.  For "DB" version(1,3,5) 1 this is always
           0.

       "db_version_patch"
           From i_db.U:

           This variable contains the patch version(1,3,5) number of Berkeley "DB"
           found in(1,8) the <db.h> header file.  For "DB" version(1,3,5) 1 this is always
           0.

       "defvoidused"
           From voidflags.U:

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

       "direntrytype"
           From i_dirent.U:

           This symbol is set(7,n,1 builtins) 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(1,n) 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(1,8) a double.

       "drand01"
           From randfunc.U:

           Indicates the macro to be used to generate normalized random(3,4,6) num-
           bers.  Uses randfunc, often divided by (double) (((unsigned long) 1
           << randbits)) in(1,8) order to normalize the result.  In C programs, the
           macro "Drand01" is mapped to drand01.

       "drand48_r_proto"
           From d_drand48_r.U:

           This variable encodes the prototype of drand48_r.  It is zero if(3,n)
           d_drand48_r is undef, and one of the "REENTRANT_PROTO_T_ABC" macros
           of reentr.h if(3,n) d_drand48_r is defined.

       "dynamic_ext"
           From Extensions.U:

           This variable holds a list of "XS" extension files we want to link(1,2)
           dynamically into the package.  It is used by Makefile.

       e


       "eagain"
           From nblock_io.U:

           This variable bears the symbolic errno code set(7,n,1 builtins) by read(2,n,1 builtins)() when no
           data is present on the file(1,n) and non-blocking I/O was enabled (oth-
           erwise, read(2,n,1 builtins)() blocks naturally).

       "ebcdic"
           From ebcdic.U:

           This variable conditionally defines "EBCDIC" if(3,n) this system uses
           "EBCDIC" encoding.  Among other things, this means that the charac-
           ter ranges are not contiguous.  See trnl.U

       "echo(1,3x,1 builtins)"
           From Loc.U:

           This variable is used internally by Configure to determine the full
           pathname (if(3,n) any) of the echo(1,3x,1 builtins) program.  After Configure runs, the
           value is reset(1,7,1 tput) to a plain "echo(1,3x,1 builtins)" and is not useful.

       "egrep"
           From Loc.U:

           This variable is used internally by Configure to determine the full
           pathname (if(3,n) any) of the egrep program.  After Configure runs, the
           value is reset(1,7,1 tput) 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.

       "endgrent_r_proto"
           From d_endgrent_r.U:

           This variable encodes the prototype of endgrent_r.  It is zero if(3,n)
           d_endgrent_r is undef, and one of the "REENTRANT_PROTO_T_ABC"
           macros of reentr.h if(3,n) d_endgrent_r is defined.

       "endhostent_r_proto"
           From d_endhostent_r.U:

           This variable encodes the prototype of endhostent_r.  It is zero if(3,n)
           d_endhostent_r is undef, and one of the "REENTRANT_PROTO_T_ABC"
           macros of reentr.h if(3,n) d_endhostent_r is defined.

       "endnetent_r_proto"
           From d_endnetent_r.U:

           This variable encodes the prototype of endnetent_r.  It is zero if(3,n)
           d_endnetent_r is undef, and one of the "REENTRANT_PROTO_T_ABC"
           macros of reentr.h if(3,n) d_endnetent_r is defined.

       "endprotoent_r_proto"
           From d_endprotoent_r.U:

           This variable encodes the prototype of endprotoent_r.  It is zero
           if(3,n) d_endprotoent_r is undef, and one of the "REENTRANT_PROTO_T_ABC"
           macros of reentr.h if(3,n) d_endprotoent_r is defined.

       "endpwent_r_proto"
           From d_endpwent_r.U:

           This variable encodes the prototype of endpwent_r.  It is zero if(3,n)
           d_endpwent_r is undef, and one of the "REENTRANT_PROTO_T_ABC"
           macros of reentr.h if(3,n) d_endpwent_r is defined.

       "endservent_r_proto"
           From d_endservent_r.U:

           This variable encodes the prototype of endservent_r.  It is zero if(3,n)
           d_endservent_r is undef, and one of the "REENTRANT_PROTO_T_ABC"
           macros of reentr.h if(3,n) d_endservent_r is defined.

       "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(1,n) 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(1,3,n)"
           From Loc.U:

           This variable is used internally by Configure to determine the full
           pathname (if(3,n) any) of the expr(1,3,n) program.  After Configure runs, the
           value is reset(1,7,1 tput) to a plain "expr(1,3,n)" 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 avail-
           able.

       "extras"
           From Extras.U