/* Test of perror() function.

   Copyright (C) 2011-2017 Free Software Foundation, Inc.

   This program is free software; you can redistribute it and/or modify

   it under the terms of the GNU General Public License as published by

   the Free Software Foundation; either version 3, or (at your option)

   any later version.

   This program is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License

   along with this program; if not, see <http://www.gnu.org/licenses/>.  */

#include <config.h>

#include <stdio.h>

#include <errno.h>

#include <string.h>

#include <unistd.h>

/* This test intentionally parses stderr.  So, we arrange to have fd 10

   (outside the range of interesting fd's during the test) set up to

   duplicate the original stderr.  */

#define BACKUP_STDERR_FILENO 10

#define ASSERT_STREAM myerr

#include "macros.h"

static FILE *myerr;

#define BASE "test-perror2"

int

main (void)

{

  /* We change fd 2 later, so save it in fd 10.  */

  if (dup2 (STDERR_FILENO, BACKUP_STDERR_FILENO) != BACKUP_STDERR_FILENO

      || (myerr = fdopen (BACKUP_STDERR_FILENO, "w")) == NULL)

    return 2;

  ASSERT (freopen (BASE ".tmp", "w+", stderr) == stderr);

  /* Test that perror does not clobber strerror buffer.  */

  {

    const char *msg1;

    const char *msg2;

    const char *msg3;

    const char *msg4;

    char *str1;

    char *str2;

    char *str3;

    char *str4;

    msg1 = strerror (ENOENT);

    ASSERT (msg1);

    str1 = strdup (msg1);

    ASSERT (str1);

    msg2 = strerror (ERANGE);

    ASSERT (msg2);

    str2 = strdup (msg2);

    ASSERT (str2);

    msg3 = strerror (-4);

    ASSERT (msg3);

    str3 = strdup (msg3);

    ASSERT (str3);

    msg4 = strerror (1729576);

    ASSERT (msg4);

    str4 = strdup (msg4);

    ASSERT (str4);

    errno = EACCES;

    perror ("");

    errno = -5;

    perror ("");

    ASSERT (!ferror (stderr));

    ASSERT (msg1 == msg2 || msg1 == msg4 || STREQ (msg1, str1));

    ASSERT (msg2 == msg4 || STREQ (msg2, str2));

    ASSERT (msg3 == msg4 || STREQ (msg3, str3));

    ASSERT (STREQ (msg4, str4));

    free (str1);

    free (str2);

    free (str3);

    free (str4);

  }

  /* Test that perror uses the same message as strerror.  */

  {

    int errs[] = { EACCES, 0, -3, };

    int i;

    for (i = 0; i < SIZEOF (errs); i++)

      {

        char buf[256];

        char *err = strerror (errs[i]);

        ASSERT (err);

        ASSERT (strlen (err) < sizeof buf);

        rewind (stderr);

        ASSERT (ftruncate (fileno (stderr), 0) == 0);

        errno = errs[i];

        perror (NULL);

        ASSERT (!ferror (stderr));

        rewind (stderr);

        ASSERT (fgets (buf, sizeof buf, stderr) == buf);

        ASSERT (strstr (buf, err));

      }

  }

  /* Test that perror reports write failure.  */

  {

    ASSERT (freopen (BASE ".tmp", "r", stderr) == stderr);

    ASSERT (setvbuf (stderr, NULL, _IONBF, BUFSIZ) == 0);

    errno = -1;

    ASSERT (!ferror (stderr));

    perror (NULL);

#if 0

    /* Commented out until cygwin behaves:

       http://sourceware.org/ml/newlib/2011/msg00228.html */

    ASSERT (errno > 0);

    /* Commented out until glibc behaves:

       http://sourceware.org/bugzilla/show_bug.cgi?id=12792 */

    ASSERT (ferror (stderr));

#endif

  }

  ASSERT (fclose (stderr) == 0);

  ASSERT (remove (BASE ".tmp") == 0);

  return 0;

}