# fopen.m4 serial 11

dnl Copyright (C) 2007-2020 Free Software Foundation, Inc.

dnl This file is free software; the Free Software Foundation

dnl gives unlimited permission to copy and/or distribute it,

dnl with or without modifications, as long as this notice is preserved.

AC_DEFUN([gl_FUNC_FOPEN],

[

  AC_REQUIRE([gl_STDIO_H_DEFAULTS])

  AC_REQUIRE([AC_CANONICAL_HOST])

  case "$host_os" in

    mingw* | pw*)

      dnl Replace fopen, for handling of "/dev/null".

      REPLACE_FOPEN=1

      dnl fopen on mingw also has the trailing slash bug.

      gl_cv_func_fopen_slash="guessing no"

      ;;

    *)

      dnl fopen("foo/", "w") should not create a file when the file name has a

      dnl trailing slash.

      AC_CACHE_CHECK([whether fopen recognizes a trailing slash],

        [gl_cv_func_fopen_slash],

        [

          AC_RUN_IFELSE(

            [AC_LANG_SOURCE([[

#include <stddef.h>

#include <stdio.h>

int main ()

{

  FILE *fp = fopen ("conftest.sl/", "w");

  int result = (fp != NULL);

  if (fp != NULL)

    fclose (fp);

  return result;

}]])],

            [gl_cv_func_fopen_slash=yes],

            [gl_cv_func_fopen_slash=no],

            [

changequote(,)dnl

             case "$host_os" in

               aix* | hpux* | solaris2.[0-9] | solaris2.[0-9].*)

                 gl_cv_func_fopen_slash="guessing no" ;;

               *)

                 gl_cv_func_fopen_slash="guessing yes" ;;

             esac

changequote([,])dnl

            ])

          rm -f conftest.sl

        ])

      ;;

  esac

  case "$gl_cv_func_fopen_slash" in

    *no)

      AC_DEFINE([FOPEN_TRAILING_SLASH_BUG], [1],

        [Define to 1 if fopen() fails to recognize a trailing slash.])

      REPLACE_FOPEN=1

      ;;

  esac

])

AC_DEFUN([gl_FUNC_FOPEN_GNU],

[

  AC_REQUIRE([gl_FUNC_FOPEN])

  AC_CACHE_CHECK([whether fopen supports the mode character 'x'],

    [gl_cv_func_fopen_mode_x],

    [rm -f conftest.x

     AC_RUN_IFELSE(

       [AC_LANG_SOURCE([[

#include <stdio.h>

#include <errno.h>

int main ()

{

  FILE *fp;

  fp = fopen ("conftest.x", "w");

  fclose (fp);

  fp = fopen ("conftest.x", "wx");

  if (fp != NULL)

    /* 'x' ignored */

    return 1;

  else if (errno == EEXIST)

    return 0;

  else

    /* 'x' rejected */

    return 2;

}]])],

       [gl_cv_func_fopen_mode_x=yes],

       [gl_cv_func_fopen_mode_x=no],

       [case "$host_os" in

          # Guess yes on glibc and musl systems.

          linux*-gnu* | gnu* | kfreebsd*-gnu | *-musl*)

            gl_cv_func_fopen_mode_x="guessing yes" ;;

          # If we don't know, obey --enable-cross-guesses.

          *)

            gl_cv_func_fopen_mode_x="$gl_cross_guess_normal" ;;

        esac

       ])

     rm -f conftest.x

    ])

  AC_CACHE_CHECK([whether fopen supports the mode character 'e'],

    [gl_cv_func_fopen_mode_e],

    [echo foo > conftest.x

     AC_RUN_IFELSE(

       [AC_LANG_SOURCE([[

#include <stdio.h>

#include <errno.h>

#include <fcntl.h>

int main ()

{

  FILE *fp = fopen ("conftest.x", "re");

  if (fp != NULL)

    {

      if (fcntl (fileno (fp), F_GETFD) & FD_CLOEXEC)

        return 0;

      else

        /* 'e' ignored */

        return 1;

    }

  else

    /* 'e' rejected */

    return 2;

}]])],

       [gl_cv_func_fopen_mode_e=yes],

       [gl_cv_func_fopen_mode_e=no],

       [case "$host_os" in

          # Guess yes on glibc and musl systems.

          linux*-gnu* | gnu* | kfreebsd*-gnu | *-musl*)

            gl_cv_func_fopen_mode_e="guessing yes" ;;

          # Guess no on native Windows.

          mingw*)

            gl_cv_func_fopen_mode_e="guessing no" ;;

          # If we don't know, obey --enable-cross-guesses.

          *)

            gl_cv_func_fopen_mode_e="$gl_cross_guess_normal" ;;

        esac

       ])

     rm -f conftest.x

    ])

  case "$gl_cv_func_fopen_mode_x" in

    *no) REPLACE_FOPEN=1 ;;

  esac

  case "$gl_cv_func_fopen_mode_e" in

    *no) REPLACE_FOPEN=1 ;;

  esac

])

# Prerequisites of lib/fopen.c.

AC_DEFUN([gl_PREREQ_FOPEN], [:])