lib:Config

See the current Perl documentation for lib:Config.

Here is our local, out-dated (pre-5.6) version:

Config - access Perl configuration information

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

    use Config qw(myconfig config_sh config_vars);

    print myconfig();

    print con
    

    

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 perlrun.

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 perlrun.




EXAMPLE

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


    use Config;
    use strict;


    my %sig_num;
    my @sig_name;
    unless($Config{sig_name} && $Config{sig_num}) {
        die "No sigs?";
    } else {
        my @names = split ' ', $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 perlguts 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.


Continue to the rest of this document