m4/mkstemp.m4

   1 #serial 23
   2
   3 # Copyright (C) 2001, 2003-2007, 2009-2014 Free Software Foundation, Inc.
   4 # This file is free software; the Free Software Foundation
   5 # gives unlimited permission to copy and/or distribute it,
   6 # with or without modifications, as long as this notice is preserved.
   7
   8 # On some hosts (e.g., HP-UX 10.20, SunOS 4.1.4, Solaris 2.5.1), mkstemp has a
   9 # silly limit that it can create no more than 26 files from a given template.
  10 # Other systems lack mkstemp altogether.
  11 # On OSF1/Tru64 V4.0F, the system-provided mkstemp function can create
  12 # only 32 files per process.
  13 # On some hosts, mkstemp creates files with mode 0666, which is a security
  14 # problem and a violation of POSIX 2008.
  15 # On systems like the above, arrange to use the replacement function.
  16 AC_DEFUN([gl_FUNC_MKSTEMP],
  17 [
  18   AC_REQUIRE([gl_STDLIB_H_DEFAULTS])
  19   AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
  20
  21   AC_CHECK_FUNCS_ONCE([mkstemp])
  22   if test $ac_cv_func_mkstemp = yes; then
  23     AC_CACHE_CHECK([for working mkstemp],
  24       [gl_cv_func_working_mkstemp],
  25       [
  26         mkdir conftest.mkstemp
  27         AC_RUN_IFELSE(
  28           [AC_LANG_PROGRAM(
  29             [AC_INCLUDES_DEFAULT],
  30             [[int result = 0;
  31               int i;
  32               off_t large = (off_t) 4294967295u;
  33               if (large < 0)
  34                 large = 2147483647;
  35               umask (0);
  36               for (i = 0; i < 70; i++)
  37                 {
  38                   char templ[] = "conftest.mkstemp/coXXXXXX";
  39                   int (*mkstemp_function) (char *) = mkstemp;
  40                   int fd = mkstemp_function (templ);
  41                   if (fd < 0)
  42                     result |= 1;
  43                   else
  44                     {
  45                       struct stat st;
  46                       if (lseek (fd, large, SEEK_SET) != large)
  47                         result |= 2;
  48                       if (fstat (fd, &st) < 0)
  49                         result |= 4;
  50                       else if (st.st_mode & 0077)
  51                         result |= 8;
  52                       if (close (fd))
  53                         result |= 16;
  54                     }
  55                 }
  56               return result;]])],
  57           [gl_cv_func_working_mkstemp=yes],
  58           [gl_cv_func_working_mkstemp=no],
  59           [case "$host_os" in
  60                      # Guess yes on glibc systems.
  61              *-gnu*) gl_cv_func_working_mkstemp="guessing yes" ;;
  62                      # If we don't know, assume the worst.
  63              *)      gl_cv_func_working_mkstemp="guessing no" ;;
  64            esac
  65           ])
  66         rm -rf conftest.mkstemp
  67       ])
  68     case "$gl_cv_func_working_mkstemp" in
  69       *yes) ;;
  70       *)
  71         REPLACE_MKSTEMP=1
  72         ;;
  73     esac
  74   else
  75     HAVE_MKSTEMP=0
  76   fi
  77 ])
  78
  79 # Prerequisites of lib/mkstemp.c.
  80 AC_DEFUN([gl_PREREQ_MKSTEMP],
  81 [
  82 ])