tests/test-perror2.c

   1 /* Test of perror() function.
   2    Copyright (C) 2011-2020 Free Software Foundation, Inc.
   3
   4    This program is free software; you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation; either version 3, or (at your option)
   7    any later version.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program; if not, see <https://www.gnu.org/licenses/>.  */
  16
  17 #include <config.h>
  18
  19 #include <stdio.h>
  20
  21 #include <errno.h>
  22 #include <string.h>
  23 #include <unistd.h>
  24
  25 /* This test intentionally parses stderr.  So, we arrange to have fd 10
  26    (outside the range of interesting fd's during the test) set up to
  27    duplicate the original stderr.  */
  28 #define BACKUP_STDERR_FILENO 10
  29 #define ASSERT_STREAM myerr
  30 #include "macros.h"
  31
  32 static FILE *myerr;
  33
  34 #define BASE "test-perror2"
  35
  36 int
  37 main (void)
  38 {
  39   /* We change fd 2 later, so save it in fd 10.  */
  40   if (dup2 (STDERR_FILENO, BACKUP_STDERR_FILENO) != BACKUP_STDERR_FILENO
  41       || (myerr = fdopen (BACKUP_STDERR_FILENO, "w")) == NULL)
  42     return 2;
  43
  44   ASSERT (freopen (BASE ".tmp", "w+", stderr) == stderr);
  45
  46   /* Test that perror does not clobber strerror buffer.  */
  47   {
  48     const char *msg1;
  49     const char *msg2;
  50     const char *msg3;
  51     const char *msg4;
  52     char *str1;
  53     char *str2;
  54     char *str3;
  55     char *str4;
  56
  57     msg1 = strerror (ENOENT);
  58     ASSERT (msg1);
  59     str1 = strdup (msg1);
  60     ASSERT (str1);
  61
  62     msg2 = strerror (ERANGE);
  63     ASSERT (msg2);
  64     str2 = strdup (msg2);
  65     ASSERT (str2);
  66
  67     msg3 = strerror (-4);
  68     ASSERT (msg3);
  69     str3 = strdup (msg3);
  70     ASSERT (str3);
  71
  72     msg4 = strerror (1729576);
  73     ASSERT (msg4);
  74     str4 = strdup (msg4);
  75     ASSERT (str4);
  76
  77     errno = EACCES;
  78     perror ("");
  79     errno = -5;
  80     perror ("");
  81     ASSERT (!ferror (stderr));
  82     ASSERT (STREQ (msg4, str4));
  83
  84     free (str1);
  85     free (str2);
  86     free (str3);
  87     free (str4);
  88   }
  89
  90   /* Test that perror uses the same message as strerror.  */
  91   {
  92     int errs[] = { EACCES, 0, -3, };
  93     int i;
  94     for (i = 0; i < SIZEOF (errs); i++)
  95       {
  96         char buf[256];
  97         char *err = strerror (errs[i]);
  98
  99         ASSERT (err);
 100         ASSERT (strlen (err) < sizeof buf);
 101         rewind (stderr);
 102         ASSERT (ftruncate (fileno (stderr), 0) == 0);
 103         errno = errs[i];
 104         perror (NULL);
 105         ASSERT (!ferror (stderr));
 106         rewind (stderr);
 107         ASSERT (fgets (buf, sizeof buf, stderr) == buf);
 108         ASSERT (strstr (buf, err));
 109       }
 110   }
 111
 112   /* Test that perror reports write failure.  */
 113   {
 114     ASSERT (freopen (BASE ".tmp", "r", stderr) == stderr);
 115     ASSERT (setvbuf (stderr, NULL, _IONBF, BUFSIZ) == 0);
 116     errno = -1;
 117     ASSERT (!ferror (stderr));
 118     perror (NULL);
 119 #if 0
 120     /* Commented out until cygwin behaves:
 121        https://sourceware.org/ml/newlib/2011/msg00228.html */
 122     ASSERT (errno > 0);
 123     /* Commented out until glibc behaves:
 124        https://sourceware.org/bugzilla/show_bug.cgi?id=12792 */
 125     ASSERT (ferror (stderr));
 126 #endif
 127   }
 128
 129   ASSERT (fclose (stderr) == 0);
 130   ASSERT (remove (BASE ".tmp") == 0);
 131
 132   return 0;
 133 }