gnulib/import/m4/getlogin_r.m4

   1 #serial 11
   2
   3 # Copyright (C) 2005-2007, 2009-2016 Free Software Foundation, Inc.
   4 #
   5 # This file is free software; the Free Software Foundation
   6 # gives unlimited permission to copy and/or distribute it,
   7 # with or without modifications, as long as this notice is preserved.
   8
   9 dnl From Derek Price
  10 dnl
  11 dnl Provide getlogin_r when the system lacks it.
  12 dnl
  13
  14 AC_DEFUN([gl_FUNC_GETLOGIN_R],
  15 [
  16   AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
  17
  18   dnl Persuade glibc <unistd.h> to declare getlogin_r().
  19   dnl Persuade Solaris <unistd.h> to provide the POSIX compliant declaration of
  20   dnl getlogin_r().
  21   AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
  22
  23   AC_CHECK_DECLS_ONCE([getlogin_r])
  24   if test $ac_cv_have_decl_getlogin_r = no; then
  25     HAVE_DECL_GETLOGIN_R=0
  26   fi
  27
  28   AC_CHECK_FUNCS_ONCE([getlogin_r])
  29   if test $ac_cv_func_getlogin_r = no; then
  30     HAVE_GETLOGIN_R=0
  31   else
  32     HAVE_GETLOGIN_R=1
  33     dnl On OSF/1 5.1, getlogin_r returns a truncated result if the buffer is
  34     dnl not large enough.
  35     AC_REQUIRE([AC_CANONICAL_HOST])
  36     AC_CACHE_CHECK([whether getlogin_r works with small buffers],
  37       [gl_cv_func_getlogin_r_works],
  38       [
  39         dnl Initial guess, used when cross-compiling.
  40 changequote(,)dnl
  41         case "$host_os" in
  42                 # Guess no on OSF/1.
  43           osf*) gl_cv_func_getlogin_r_works="guessing no" ;;
  44                 # Guess yes otherwise.
  45           *)    gl_cv_func_getlogin_r_works="guessing yes" ;;
  46         esac
  47 changequote([,])dnl
  48         AC_RUN_IFELSE(
  49           [AC_LANG_SOURCE([[
  50 #include <stddef.h>
  51 #include <unistd.h>
  52 #if !HAVE_DECL_GETLOGIN_R
  53 extern
  54 # ifdef __cplusplus
  55 "C"
  56 # endif
  57 int getlogin_r (char *, size_t);
  58 #endif
  59 int
  60 main (void)
  61 {
  62   int result = 0;
  63   char buf[100];
  64
  65   if (getlogin_r (buf, 0) == 0)
  66     result |= 16;
  67   if (getlogin_r (buf, 1) == 0)
  68     result |= 17;
  69   return result;
  70 }]])],
  71           [gl_cv_func_getlogin_r_works=yes],
  72           [case $? in
  73              16 | 17) gl_cv_func_getlogin_r_works=no ;;
  74            esac
  75           ],
  76           [:])
  77       ])
  78     case "$gl_cv_func_getlogin_r_works" in
  79       *yes) ;;
  80       *) REPLACE_GETLOGIN_R=1 ;;
  81     esac
  82   fi
  83 ])
  84
  85 AC_DEFUN([gl_PREREQ_GETLOGIN_R],
  86 [
  87   AC_CHECK_DECLS_ONCE([getlogin])
  88 ])