mdw@git.distorted.org.uk Git - runlisp/blob - m4/mdw-decl-environ.m4

   1 dnl -*-autoconf-*-
   2
   3 dnl --- *@-mdw_DECL_ENVIRON-@* ---
   4 dnl
   5 dnl Author:     Mark Wooding
   6 dnl
   7 dnl Synopsis:   mdw_DECL_ENVIRON
   8 dnl
   9 dnl Arguments:  ---
  10 dnl
  11 dnl Use:        Searches for a declaration of the global `environ' variable.
  12 dnl             If one is found in one of the `usual' places, DECL_ENVIRON
  13 dnl             is defined as a preprocessor symbol.
  14
  15 AC_DEFUN([mdw_DECL_ENVIRON],
  16 [AC_CACHE_CHECK([for declaration of \`environ'], mdw_cv_environ,
  17 [AC_EGREP_CPP([\<environ\>],
  18 [#include <sys/types.h>
  19 #if HAVE_UNISTD_H
  20 #include <unistd.h>
  21 #endif
  22 #if STDC_HEADERS
  23 #include <stdlib.h>
  24 #include <stddef.h>
  25 #endif], [mdw_cv_environ=yes], [mdw_cv_environ=no])])
  26 if test $mdw_cv_environ = yes; then
  27   AC_DEFINE([DECL_ENVIRON], [1],
  28             [Define if you have the `environ' vector of environment variables.])
  29 fi])