Config

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



NAME
       Config - access Perl configuration information

SYNOPSIS
           use Config;
           if ($Config{'cc'} =~ /gcc/) {
               print "built by gcc\n";
           }

           use Config qw(myconfig config_sh config_vars);

           print myconfig();

           print config_sh();

           config_vars(qw(osname archname));


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

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

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

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

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

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

             name='value';

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

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

           use Config;
           use strict;

           my %sig_num;
           my @sig_name;
           unless($Config{sig_name} && $Config{sig_num}) {
               die "No sigs?";
           } else {
               my @names = split ' ', $Config{sig_name};
               @sig_num{@names} = split ' ', $Config{sig_num};
               foreach (@names) {
                   $sig_name[$sig_num{$_}] ⎪⎪= $_;
               }
           }

           print "signal #17 = $sig_name[17]\n";
           if ($sig_num{ALRM}) {
               print "SIGALRM is $sig_num{ALRM}\n";
           }


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

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

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

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

       M

       Mcc  From Loc.U:

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

       _

       _a   From Unix.U:

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

       _exe From Unix.U:

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

       _o   From Unix.U:

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

       a

       afs  From afs.U:

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

       alignbytes
            From alignbytes.U:

            This variable holds the number of bytes required to align a
            double. Usual values are 2, 4 and 8.

       ansi2knr
            From ansi2knr.U:

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

       aphostname
            From d_gethname.U:

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

       apiversion
            From patchlevel.U:

            This is a number which identifies the lowest version of perl to
            have an API (for XS extensions) compatible with the present
            version.  For example, for 5.005_01, the apiversion should be
            5.005, since 5.005_01 should be binary compatible with 5.005.
            This should probably be incremented manually somehow, perhaps from
            patchlevel.h.  For now, we'll guess maintenance subversions will
            retain binary compatibility.

       ar   From Loc.U:

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

       archlib
            From archlib.U:

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

       archlibexp
            From archlib.U:

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

       archname
            From archname.U:

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

       archobjs
            From Unix.U:

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

       awk  From Loc.U:

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

       b

       baserev
            From baserev.U:

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

       bash From Loc.U:

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

       bin  From bin.U:

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

       binexp
            From bin.U:

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

       bison
            From Loc.U:

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

       byacc
            From Loc.U:

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

       byteorder
            From byteorder.U:

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

       c

       c    From n.U:

            This variable contains the \c string if that is what causes the
            echo command to suppress newline.  Otherwise it is null.  Correct
            usage is

                    $echo $n "prompt for a question: $c".


       castflags
            From d_castneg.U:

            This variable contains a flag that precise difficulties the
            compiler has casting odd floating values to unsigned long:

                    0 = ok

                    1 = couldn't cast < 0

                    2 = couldn't cast >= 0x80000000

                    4 = couldn't cast in argument expression list


       cat  From Loc.U:

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

       cc   From cc.U:

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

       cccdlflags
            From dlsrc.U:

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

       ccdlflags
            From dlsrc.U:

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

       ccflags
            From ccflags.U:

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

       cf_by
            From cf_who.U:

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

       cf_email
            From cf_email.U:

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

       cf_time
            From cf_who.U:

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

       chgrp
            From Loc.U:

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

       chmod
            From Loc.U:

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

       chown
            From Loc.U:

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

       clocktype
            From d_times.U:

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

       comm From Loc.U:

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

       compress
            From Loc.U:

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

       contains
            From contains.U:

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

       cp   From Loc.U:

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

       cpio From Loc.U:

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

       cpp  From Loc.U:

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

       cpp_stuff
            From cpp_stuff.U:

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

       cppflags
            From ccflags.U:

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

       cpplast
            From cppstdin.U:

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

       cppminus
            From cppstdin.U:

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

       cpprun
            From cppstdin.U:

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

       cppstdin
            From cppstdin.U:

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

       cryptlib
            From d_crypt.U:

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

       csh  From Loc.U:

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

       d

       d_Gconvert
            From d_gconvert.U:

            This variable holds what Gconvert is defined as to convert
            floating point numbers into strings. It could be gconvert or a
            more complex macro emulating gconvert with gcvt() or sprintf.

       d_access
            From d_access.U:

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

       d_alarm
            From d_alarm.U:

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

       d_archlib
            From archlib.U:

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

       d_attribut
            From d_attribut.U:

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

       d_bcmp
            From d_bcmp.U:

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

       d_bcopy
            From d_bcopy.U:

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

       d_bsd
            From Guess.U:

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

       d_bsdgetpgrp
            From d_getpgrp.U:

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

       d_bsdsetpgrp
            From d_setpgrp.U:

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

       d_bzero
            From d_bzero.U:

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

       d_casti32
            From d_casti32.U:

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

       d_castneg
            From d_castneg.U:

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

       d_charvspr
            From d_vprintf.U:

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

       d_chown
            From d_chown.U:

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

       d_chroot
            From d_chroot.U:

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

       d_chsize
            From d_chsize.U:

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

       d_closedir
            From d_closedir.U:

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

       d_const
            From d_const.U:

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

       d_crypt
            From d_crypt.U:

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

       d_csh
            From d_csh.U:

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

       d_cuserid
            From d_cuserid.U:

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

       d_dbl_dig
            From d_dbl_dig.U:

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

       d_difftime
            From d_difftime.U:

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

       d_dirnamlen
            From i_dirent.U:

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

       d_dlerror
            From d_dlerror.U:

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

       d_dlopen
            From d_dlopen.U:

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

       d_dlsymun
            From d_dlsymun.U:

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

       d_dosuid
            From d_dosuid.U:

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

       d_dup2
            From d_dup2.U:

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

       d_endgrent
            From d_endgrent.U:

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

       d_endhent
            From d_endhent.U:

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

       d_endnent
            From d_endnent.U:

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

       d_endpent
            From d_endpent.U:

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

       d_endpwent
            From d_endpwent.U:

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

       d_endsent
            From d_endsent.U:

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

       d_eofnblk
            From nblock_io.U:

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

       d_eunice
            From Guess.U:

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

       d_fchmod
            From d_fchmod.U:

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

       d_fchown
            From d_fchown.U:

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

       d_fcntl
            From d_fcntl.U:

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

       d_fd_macros
            From d_fd_set.U:

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

       d_fd_set
            From d_fd_set.U:

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

       d_fds_bits
            From d_fd_set.U:

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

       d_fgetpos
            From d_fgetpos.U:

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

       d_flexfnam
            From d_flexfnam.U:

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

       d_flock
            From d_flock.U:

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

       d_fork
            From d_fork.U:

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

       d_fpathconf
            From d_pathconf.U:

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

       d_fsetpos
            From d_fsetpos.U:

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

       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_getgrent
            From d_getgrent.U:

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

       d_getgrps
            From d_getgrps.U:

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

       d_gethbyaddr
            From d_gethbyad.U:

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

       d_gethbyname
            From d_gethbynm.U:

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

       d_gethent
            From d_gethent.U:

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

       d_gethname
            From d_gethname.U:

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

       d_gethostprotos
            From d_gethostprotos.U:

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

       d_getlogin
            From d_getlogin.U:

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

       d_getnbyaddr
            From d_getnbyad.U:

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

       d_getnbyname
            From d_getnbynm.U:

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

       d_getnent
            From d_getnent.U:

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

       d_getnetprotos
            From d_getnetprotos.U:

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

       d_getpbyname
            From d_getprotby.U:

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

       d_getpbynumber
            From d_getprotby.U:

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

       d_getpent
            From d_getpent.U:

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

       d_getpgid
            From d_getpgid.U:

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

       d_getpgrp2
            From d_getpgrp2.U:

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

       d_getpgrp
            From d_getpgrp.U:

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

       d_getppid
            From d_getppid.U:

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

       d_getprior
            From d_getprior.U:

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

       d_getprotoprotos
            From d_getprotoprotos.U:

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

       d_getpwent
            From d_getpwent.U:

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

       d_getsbyname
            From d_getsrvby.U:

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

       d_getsbyport
            From d_getsrvby.U:

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

       d_getsent
            From d_getsent.U:

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

       d_getservprotos
            From d_getservprotos.U:

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

       d_gettimeod
            From d_ftime.U:

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

       d_gnulibc
            From d_gnulibc.U:

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

       d_grpasswd
            From i_grp.U:

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

       d_htonl
            From d_htonl.U:

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

       d_index
            From d_strchr.U:

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

       d_inetaton
            From d_inetaton.U:

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

       d_isascii
            From d_isascii.U:

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

       d_killpg
            From d_killpg.U:

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

       d_lchown
            From d_lchown.U:

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

       d_link
            From d_link.U:

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

       d_locconv
            From d_locconv.U:

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

       d_lockf
            From d_lockf.U:

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

       d_longdbl
            From d_longdbl.U:

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

       d_longlong
            From d_longlong.U:

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

       d_lstat
            From d_lstat.U:

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

       d_mblen
            From d_mblen.U:

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

       d_mbstowcs
            From d_mbstowcs.U:

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

       d_mbtowc
            From d_mbtowc.U:

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

       d_memcmp
            From d_memcmp.U:

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

       d_memcpy
            From d_memcpy.U:

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

       d_memmove
            From d_memmove.U:

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

       d_memset
            From d_memset.U:

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

       d_mkdir
            From d_mkdir.U:

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

       d_mkfifo
            From d_mkfifo.U:

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

       d_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_msg
            From d_msg.U:

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

       d_msgctl
            From d_msgctl.U:

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

       d_msgget
            From d_msgget.U:

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

       d_msgrcv
            From d_msgrcv.U:

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

       d_msgsnd
            From d_msgsnd.U:

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

       d_mymalloc
            From mallocsrc.U:

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

       d_nice
            From d_nice.U:

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

       d_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 potneially meaningful if usethreads is
            set.

       d_oldsock
            From d_socket.U:

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

       d_open3
            From d_open3.U:

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

       d_pathconf
            From d_pathconf.U:

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

       d_pause
            From d_pause.U:

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

       d_phostname
            From d_gethname.U:

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

       d_pipe
            From d_pipe.U:

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

       d_poll
            From d_poll.U:

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

       d_portable
            From d_portable.U:

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

       d_pthread_yield
            From d_pthread_y.U:

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

       d_pthreads_created_joinable
            From d_pthreadj.U:

            This variable conditionally defines the PTHREADS_CREATED_JOINABLE
            symbol if pthreads are created in the joinable (aka undetached)
            state.

       d_pwage
            From i_pwd.U:

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

       d_pwchange
            From i_pwd.U:

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

       d_pwclass
            From i_pwd.U:

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

       d_pwcomment
            From i_pwd.U:

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

       d_pwexpire
            From i_pwd.U:

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

       d_pwgecos
            From i_pwd.U:

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

       d_pwpasswd
            From i_pwd.U:

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

       d_pwquota
            From i_pwd.U:

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

       d_readdir
            From d_readdir.U:

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

       d_readlink
            From d_readlink.U:

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

       d_rename
            From d_rename.U:

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

       d_rewinddir
            From d_readdir.U:

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

       d_rmdir
            From d_rmdir.U:

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

       d_safebcpy
            From d_safebcpy.U:

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

       d_safemcpy
            From d_safemcpy.U:

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

       d_sanemcmp
            From d_sanemcmp.U:

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

       d_sched_yield
            From d_pthread_y.U:

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

       d_seekdir
            From d_readdir.U:

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

       d_select
            From d_select.U:

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

       d_sem
            From d_sem.U:

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

       d_semctl
            From d_semctl.U:

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

       d_semctl_semid_ds
            From d_union_senum.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_senum.U:

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

       d_semget
            From d_semget.U:

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

       d_semop
            From d_semop.U:

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

       d_setegid
            From d_setegid.U:

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

       d_seteuid
            From d_seteuid.U:

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

       d_setgrent
            From d_setgrent.U:

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

       d_setgrps
            From d_setgrps.U:

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

       d_sethent
            From d_sethent.U:

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

       d_setlinebuf
            From d_setlnbuf.U:

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

       d_setlocale
            From d_setlocale.U:

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

       d_setnent
            From d_setnent.U:

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

       d_setpent
            From d_setpent.U:

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

       d_setpgid
            From d_setpgid.U:

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

       d_setpgrp2
            From d_setpgrp2.U:

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

       d_setpgrp
            From d_setpgrp.U:

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

       d_setprior
            From d_setprior.U:

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

       d_setpwent
            From d_setpwent.U:

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

       d_setregid
            From d_setregid.U:

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

       d_setresgid
            From d_setregid.U:

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

       d_setresuid
            From d_setreuid.U:

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

       d_setreuid
            From d_setreuid.U:

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

       d_setrgid
            From d_setrgid.U:

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

       d_setruid
            From d_setruid.U:

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

       d_setsent
            From d_setsent.U:

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

       d_setsid
            From d_setsid.U:

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

       d_setvbuf
            From d_setvbuf.U:

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

       d_sfio
            From d_sfio.U:

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

       d_shm
            From d_shm.U:

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

       d_shmat
            From d_shmat.U:

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

       d_shmatprototype
            From d_shmat.U:

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

       d_shmctl
            From d_shmctl.U:

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

       d_shmdt
            From d_shmdt.U:

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

       d_shmget
            From d_shmget.U:

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

       d_sigaction
            From d_sigaction.U:

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

       d_sigsetjmp
            From d_sigsetjmp.U:

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

       d_socket
            From d_socket.U:

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

       d_sockpair
            From d_socket.U:

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

       d_statblks
            From d_statblks.U:

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

       d_stdio_cnt_lval
            From d_stdstdio.U:

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

       d_stdio_ptr_lval
            From d_stdstdio.U:

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

       d_stdiobase
            From d_stdstdio.U:

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

       d_stdstdio
            From d_stdstdio.U:

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

       d_strchr
            From d_strchr.U:

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

       d_strcoll
            From d_strcoll.U:

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

       d_strctcpy
            From d_strctcpy.U:

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

       d_strerrm
            From d_strerror.U:

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

       d_strerror
            From d_strerror.U:

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

       d_strtod
            From d_strtod.U:

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

       d_strtol
            From d_strtol.U:

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

       d_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_strxfrm
            From d_strxfrm.U:

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

       d_suidsafe
            From d_dosuid.U:

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

       d_symlink
            From d_symlink.U:

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

       d_syscall
            From d_syscall.U:

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

       d_sysconf
            From d_sysconf.U:

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

       d_sysernlst
            From d_strerror.U:

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

       d_syserrlst
            From d_strerror.U:

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

       d_system
            From d_system.U:

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

       d_tcgetpgrp
            From d_tcgtpgrp.U:

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

       d_tcsetpgrp
            From d_tcstpgrp.U:

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

       d_telldir
            From d_readdir.U:

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

       d_time
            From d_time.U:

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

       d_times
            From d_times.U:

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

       d_truncate
            From d_truncate.U:

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

       d_tzname
            From d_tzname.U:

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

       d_umask
            From d_umask.U:

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

       d_uname
            From d_gethname.U:

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

       d_union_semun
            From d_union_senum.U:

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

       d_vfork
            From d_vfork.U:

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

       d_void_closedir
            From d_closedir.U:

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

       d_voidsig
            From d_voidsig.U:

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

       d_voidtty
            From i_sysioctl.U:

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

       d_volatile
            From d_volatile.U:

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

       d_vprintf
            From d_vprintf.U:

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

       d_wait4
            From d_wait4.U:

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

       d_waitpid
            From d_waitpid.U:

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

       d_wcstombs
            From d_wcstombs.U:

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

       d_wctomb
            From d_wctomb.U:

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

       d_xenix
            From Guess.U:

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

       date From Loc.U:

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

       db_hashtype
            From i_db.U:

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

       db_prefixtype
            From i_db.U:

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

       direntrytype
            From i_dirent.U:

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

       dlext
            From dlext.U:

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

       dlsrc
            From dlsrc.U:

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

       doublesize
            From doublesize.U:

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

       dynamic_ext
            From Extensions.U:

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

       e

       eagain
            From nblock_io.U:

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

       ebcdic
            From ebcdic.U:

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

       echo From Loc.U:

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

       egrep
            From Loc.U:

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

       emacs
            From Loc.U:

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

       eunicefix
            From Init.U:

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

       exe_ext
            From Unix.U:

            This is an old synonym for _exe.

       expr From Loc.U:

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

       extensions
            From Extensions.U:

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

       f

       find From Loc.U:

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

       firstmakefile
            From Unix.U:

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

       flex From Loc.U:

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

       fpostype
            From fpostype.U:

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

       freetype
            From mallocsrc.U:

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

       full_csh
            From d_csh.U:

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

       full_sed
            From Loc_sed.U:

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

       g

       gccversion
            From cc.U:

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

       gidtype
            From gidtype.U:

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

       grep From Loc.U:

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

       groupcat
            From nis.U:

            This variable contains a command that produces the text of the
            /etc/group file.  This is normally "cat /etc/group", but can be
            "ypcat group" when NIS is used.

       groupstype
            From groupstype.U:

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

       gzip From Loc.U:

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

       h

       h_fcntl
            From h_fcntl.U:

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

       h_sysfile
            From h_sysfile.U:

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

       hint From Oldconfig.U:

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

       hostcat
            From nis.U:

            This variable contains a command that produces the text of the
            /etc/hosts file.  This is normally "cat /etc/hosts", but can be
            "ypcat hosts" when NIS is used.

       huge From models.U:

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

       i

       i_arpainet
            From i_arpainet.U:

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

       i_bsdioctl
            From i_sysioctl.U:

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

       i_db From i_db.U:

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

       i_dbm
            From i_dbm.U:

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

       i_dirent
            From i_dirent.U:

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

       i_dld
            From i_dld.U:

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

       i_dlfcn
            From i_dlfcn.U:

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

       i_fcntl
            From i_fcntl.U:

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

       i_float
            From i_float.U:

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

       i_gdbm
            From i_gdbm.U:

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

       i_grp
            From i_grp.U:

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

       i_limits
            From i_limits.U:

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

       i_locale
            From i_locale.U:

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

       i_malloc
            From i_malloc.U:

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

       i_math
            From i_math.U:

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

       i_memory
            From i_memory.U:

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

       i_ndbm
            From i_ndbm.U:

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

       i_netdb
            From i_netdb.U:

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

       i_neterrno
            From i_neterrno.U:

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

       i_niin
            From i_niin.U:

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

       i_pwd
            From i_pwd.U:

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

       i_rpcsvcdbm
            From i_dbm.U:

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

       i_sfio
            From i_sfio.U:

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

       i_sgtty
            From i_termio.U:

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

       i_stdarg
            From i_varhdr.U:

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

       i_stddef
            From i_stddef.U:

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

       i_stdlib
            From i_stdlib.U:

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

       i_string
            From i_string.U:

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

       i_sysdir
            From i_sysdir.U:

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

       i_sysfile
            From i_sysfile.U:

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

       i_sysfilio
            From i_sysioctl.U:

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

       i_sysin
            From i_niin.U:

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

       i_sysioctl
            From i_sysioctl.U:

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

       i_sysndir
            From i_sysndir.U:

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

       i_sysparam
            From i_sysparam.U:

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

       i_sysresrc
            From i_sysresrc.U:

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

       i_sysselct
            From i_sysselct.U:

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

       i_syssockio
            From i_sysioctl.U:

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

       i_sysstat
            From i_sysstat.U:

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

       i_systime
            From i_time.U:

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

       i_systimek
            From i_time.U:

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

       i_systimes
            From i_systimes.U:

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

       i_systypes
            From i_systypes.U:

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

       i_sysun
            From i_sysun.U:

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

       i_syswait
            From i_syswait.U:

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

       i_termio
            From i_termio.U:

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

       i_termios
            From i_termio.U:

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

       i_time
            From i_time.U:

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

       i_unistd
            From i_unistd.U:

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

       i_utime
            From i_utime.U:

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

       i_values
            From i_values.U:

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

       i_varargs
            From i_varhdr.U:

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

       i_varhdr
            From i_varhdr.U:

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

       i_vfork
            From i_vfork.U:

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

       incpath
            From usrinc.U:

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

       inews
            From Loc.U:

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

       installarchlib
            From archlib.U:

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

       installbin
            From bin.U:

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

       installman1dir
            From man1dir.U:

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

       installman3dir
            From man3dir.U:

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

       installprivlib
            From privlib.U:

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

       installscript
            From scriptdir.U:

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

       installsitearch
            From sitearch.U:

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

       installsitelib
            From sitelib.U:

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

       intsize
            From intsize.U:

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

       k

       known_extensions
            From Extensions.U:

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

       ksh  From Loc.U:

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

       l

       large
            From models.U:

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

       ld   From dlsrc.U:

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

       lddlflags
            From dlsrc.U:

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

       ldflags
            From ccflags.U:

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

       less From Loc.U:

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

       lib_ext
            From Unix.U:

            This is an old synonym for _a.

       libc From libc.U:

            This variable contains the location of the C library.

       libperl
            From libperl.U:

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

       libpth
            From libpth.U:

            This variable holds the general path used to find libraries. It is
            intended to be used by other units.

       libs From libs.U:

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

       libswanted
            From Myinit.U:

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

       line From Loc.U:

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

       lint From Loc.U:

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

       lkflags
            From ccflags.U:

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

       ln   From Loc.U:

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

       lns  From lns.U:

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

       locincpth
            From ccflags.U:

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

       loclibpth
            From libpth.U:

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

       longdblsize
            From d_longdbl.U:

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

       longlongsize
            From d_longlong.U:

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

       longsize
            From intsize.U:

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

       lp   From Loc.U:

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

       lpr  From Loc.U:

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

       ls   From Loc.U:

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

       lseektype
            From lseektype.U:

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

       m

       mail From Loc.U:

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

       mailx
            From Loc.U:

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

       make From Loc.U:

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

       make_set_make
            From make.U:

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

       mallocobj
            From mallocsrc.U:

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

       mallocsrc
            From mallocsrc.U:

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

       malloctype
            From mallocsrc.U:

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

       man1dir
            From man1dir.U:

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

       man1direxp
            From man1dir.U:

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

       man1ext
            From man1dir.U:

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

       man3dir
            From man3dir.U:

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

       man3direxp
            From man3dir.U:

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

       man3ext
            From man3dir.U:

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

       medium
            From models.U:

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

       mips_type
            From usrinc.U:

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

       mkdir
            From Loc.U:

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

       models
            From models.U:

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

       modetype
            From modetype.U:

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

       more From Loc.U:

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

       mv   From Loc.U:

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

       myarchname
            From archname.U:

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

       mydomain
            From myhostname.U:

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

       myhostname
            From myhostname.U:

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

       myuname
            From Oldconfig.U:

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

       n

       n    From n.U:

            This variable contains the -n flag if that is what causes the echo
            command to suppress newline.  Otherwise it is null.  Correct usage
            is

                    $echo $n "prompt for a question: $c".


       netdb_hlen_type
            From netdbtype.U:

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

       netdb_host_type
            From netdbtype.U:

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

       netdb_name_type
            From netdbtype.U:

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

       netdb_net_type
            From netdbtype.U:

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

       nm   From Loc.U:

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

       nm_opt
            From usenm.U:

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

       nm_so_opt
            From usenm.U:

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

       nonxs_ext
            From Extensions.U:

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

       nroff
            From Loc.U:

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

       o

       o_nonblock
            From nblock_io.U:

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

       obj_ext
            From Unix.U:

            This is an old synonym for _o.

       optimize
            From ccflags.U:

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

       orderlib
            From orderlib.U:

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

       osname
            From Oldconfig.U:

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

       osvers
            From Oldconfig.U:

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

       p

       package
            From package.U:

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

       pager
            From pager.U:

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

       passcat
            From nis.U:

            This variable contains a command that produces the text of the
            /etc/passwd file.  This is normally "cat /etc/passwd", but can be
            "ypcat passwd" when NIS is used.

       patchlevel
            From patchlevel.U:

            The patchlevel level of this package.  The value of patchlevel
            comes from the patchlevel.h file.

       path_sep
            From Unix.U:

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

       perl From Loc.U:

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

       perladmin
            From perladmin.U:

            Electronic mail address of the perl5 administrator.

       perlpath
            From perlpath.U:

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

       pg   From Loc.U:

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

       phostname
            From myhostname.U:

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

       pidtype
            From pidtype.U:

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

       plibpth
            From libpth.U:

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

       pmake
            From Loc.U:

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

       pr   From Loc.U:

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

       prefix
            From prefix.U:

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

       prefixexp
            From prefix.U:

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

       privlib
            From privlib.U:

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

       privlibexp
            From privlib.U:

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

       prototype
            From prototype.U:

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

       ptrsize
            From ptrsize.U:

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

       r

       randbits
            From randbits.U:

            This variable contains the eventual value of the RANDBITS symbol,
            which indicates to the C program how many bits of random number
            the rand() function produces.

       ranlib
            From orderlib.U:

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

       rd_nodata
            From nblock_io.U:

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

       rm   From Loc.U:

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

       rmail
            From Loc.U:

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

       runnm
            From usenm.U:

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

       s

       scriptdir
            From scriptdir.U:

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

       scriptdirexp
            From scriptdir.U:

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

       sed  From Loc.U:

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

       selecttype
            From selecttype.U:

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

       sendmail
            From Loc.U:

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

       sh   From sh.U:

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

       shar From Loc.U:

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

       sharpbang
            From spitshell.U:

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

       shmattype
            From d_shmat.U:

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

       shortsize
            From intsize.U:

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

       shrpenv
            From libperl.U:

            If the user builds a shared libperl.so, then we need to tell the
            perl executable where it will be able to find the installed
            libperl.so.  One way to do this on some systems is to set the
            environment variable LD_RUN_PATH to the directory that will be the
            final location of the shared libperl.so.  The makefile can use
            this with something like

                    $shrpenv $(C<CC>) -o perl F<perlmain.o> $libperl $libs

                    Typical values are

                    shrpenv="env C<LD_RUN_PATH>=$F<archlibexp/C<CORE>>"

                    or

                    shrpenv=''

                    See the main perl F<Makefile.SH> for actual working usage.
            Alternatively, we might be able to use a command line option such
            as -R $F<archlibexp/C<CORE>> (Solaris, NetBSD) or -Wl,-rpath
            $F<archlibexp/C<CORE>> (Linux).


       shsharp
            From spitshell.U:

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

       sig_name
            From sig_name.U:

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

       sig_name_init
            From sig_name.U:

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

       sig_num
            From sig_name.U:

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

       signal_t
            From d_voidsig.U:

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

       sitearch
            From sitearch.U:

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

       sitearchexp
            From sitearch.U:

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

       sitelib
            From sitelib.U:

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

       sitelibexp
            From sitelib.U:

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

       sizetype
            From sizetype.U:

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

       sleep
            From Loc.U:

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

       smail
            From Loc.U:

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

       small
            From models.U:

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

       so   From so.U:

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

       sockethdr
            From d_socket.U:

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

       socketlib
            From d_socket.U:

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

       sort From Loc.U:

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

       spackage
            From package.U:

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

       spitshell
            From spitshell.U:

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

       split
            From models.U:

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

       src  From src.U:

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

       ssizetype
            From ssizetype.U:

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

       startperl
            From startperl.U:

            This variable contains the string to put on the front of a perl
            script to make sure (hopefully) that it runs with perl and not
            some shell. Of course, that leading line must be followed by the
            classical perl idiom:

                    eval 'exec perl -S $0 ${1+C<$@>}'

                    if $running_under_some_shell;

                    to guarantee perl startup should the shell execute the script. Note
            that this magic incatation is not understood by csh.


       startsh
            From startsh.U:

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

       static_ext
            From Extensions.U:

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

       stdchar
            From stdchar.U:

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

       stdio_base
            From d_stdstdio.U:

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

       stdio_bufsiz
            From d_stdstdio.U:

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

       stdio_cnt
            From d_stdstdio.U:

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

       stdio_filbuf
            From d_stdstdio.U:

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

       stdio_ptr
            From d_stdstdio.U:

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

       strings
            From i_string.U:

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

       submit
            From Loc.U:

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

       subversion
            From patchlevel.U:

            The subversion level of this package.  The value of subversion
            comes from the patchlevel.h file.  This is unique to perl.

       sysman
            From sysman.U:

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

       t

       tail From Loc.U:

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

       tar  From Loc.U:

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

       tbl  From Loc.U:

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

       tee  From Loc.U:

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

       test From Loc.U:

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

       timeincl
            From i_time.U:

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

       timetype
            From d_time.U:

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

       touch
            From Loc.U:

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

       tr   From Loc.U:

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

       trnl From trnl.U:

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

       troff
            From Loc.U:

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

       u

       uidtype
            From uidtype.U:

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

       uname
            From Loc.U:

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

       uniq From Loc.U:

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

       usedl
            From dlsrc.U:

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

       usemymalloc
            From mallocsrc.U:

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

       usenm
            From usenm.U:

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

       useopcode
            From Extensions.U:

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

       useperlio
            From useperlio.U:

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

       useposix
            From Extensions.U:

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

       usesfio
            From d_sfio.U:

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

       useshrplib
            From libperl.U:

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

       usethreads
            From usethreads.U:

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

       usevfork
            From d_vfork.U:

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

       usrinc
            From usrinc.U:

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

       uuname
            From Loc.U:

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

       v

       version
            From patchlevel.U:

            The full version number of this package.  This combines baserev,
            patchlevel, and subversion to get the full version number,
            including any possible subversions.  Care is taken to use the C
            locale in order to get something like 5.004 instead of 5,004.
            This is unique to perl.

       vi   From Loc.U:

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

       voidflags
            From voidflags.U:

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

       z

       zcat From Loc.U:

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

       zip  From Loc.U:

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

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



































































































































































































































































































































































































































































































































































































3rd Berkeley Distribution    perl 5.005, patch 02                    Config(3)