ETR_STRUCT_SEMUN
, 

2001-05-28

Warren Young <warren@etr-usa.com>

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Copying and distribution of this file, with or without modification, are permitted in any medium without royalty provided the copyright notice and this notice are preserved. Users of this software should generally follow the principles of the MIT License includings its disclaimer.

cryp.to ac-archive's Miscellaneous (released)

This macro checks to see if sys/sem.h defines struct semun. Some systems do, some systems don't. Your code must be able to deal with this possibility; if HAVE_STRUCT_SEMUM isn't defined for a given system, you have to define this structure before you can call functions like semctl().

You should call ETR_SYSV_IPC before this macro, to separate the check for System V IPC headers from the check for struct semun.

AC_DEFUN([ETR_STRUCT_SEMUN],
[
AC_CACHE_CHECK([for struct semun], ac_cv_struct_semun, [
        AC_TRY_COMPILE(
                [
                        #include <sys/types.h>
                        #include <sys/ipc.h>
                        #include <sys/sem.h>
                ],
                [ struct semun s; ],
                ac_cv_struct_semun=yes,
                ac_cv_struct_semun=no)
])

        if test x"$ac_cv_struct_semun" = "xyes"
        then
                AC_DEFINE(HAVE_STRUCT_SEMUN, 1,
                        [ Define if your system's sys/sem.h file defines struct semun ])
        fi
]) dnl ETR_STRUCT_SEMUN