tests/test-ftell.c

   1 /* Test of ftell() function.
   2    Copyright (C) 2007-2020 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 of the License, or
   7    (at your option) 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 /* Written by Bruno Haible <bruno@clisp.org>, 2007.  */
  18
  19 #include <config.h>
  20
  21 /* None of the files accessed by this test are large, so disable the
  22    fseek link warning if we are not using the gnulib fseek module.  */
  23 #define _GL_NO_LARGE_FILES
  24 #include <stdio.h>
  25
  26 #include "signature.h"
  27 SIGNATURE_CHECK (ftell, long, (FILE *));
  28
  29 #include "binary-io.h"
  30 #include "macros.h"
  31
  32 #ifndef FUNC_UNGETC_BROKEN
  33 # define FUNC_UNGETC_BROKEN 0
  34 #endif
  35
  36 int
  37 main (int argc, char **argv)
  38 {
  39   int ch;
  40   /* Assume stdin is seekable iff argc > 1.  */
  41   if (argc == 1)
  42     {
  43       ASSERT (ftell (stdin) == -1);
  44       return 0;
  45     }
  46
  47   /* mingw ftell is unreliable on text mode input.  */
  48   set_binary_mode (0, O_BINARY);
  49
  50   /* Simple tests.  */
  51   ASSERT (ftell (stdin) == 0);
  52
  53   ch = fgetc (stdin);
  54   ASSERT (ch == '#');
  55   ASSERT (ftell (stdin) == 1);
  56
  57   /* Test ftell after ungetc of read input.  */
  58   ch = ungetc ('#', stdin);
  59   ASSERT (ch == '#');
  60   ASSERT (ftell (stdin) == 0);
  61
  62   ch = fgetc (stdin);
  63   ASSERT (ch == '#');
  64   ASSERT (ftell (stdin) == 1);
  65
  66   /* Test ftell after fseek.  */
  67   ASSERT (fseek (stdin, 2, SEEK_SET) == 0);
  68   ASSERT (ftell (stdin) == 2);
  69
  70   /* Test ftell after random ungetc.  */
  71   ch = fgetc (stdin);
  72   ASSERT (ch == '/');
  73   ch = ungetc ('@', stdin);
  74   ASSERT (ch == '@');
  75   ASSERT (ftell (stdin) == 2);
  76
  77   ch = fgetc (stdin);
  78   ASSERT (ch == '@');
  79   ASSERT (ftell (stdin) == 3);
  80
  81   if (2 < argc)
  82     {
  83       if (FUNC_UNGETC_BROKEN)
  84         {
  85           fputs ("Skipping test: ungetc cannot handle arbitrary bytes\n",
  86                  stderr);
  87           return 77;
  88         }
  89       /* Test ftell after ungetc without read.  */
  90       ASSERT (fseek (stdin, 0, SEEK_CUR) == 0);
  91       ASSERT (ftell (stdin) == 3);
  92
  93       ch = ungetc ('~', stdin);
  94       ASSERT (ch == '~');
  95       ASSERT (ftell (stdin) == 2);
  96     }
  97
  98 #if !defined __MINT__ /* FreeMiNT has problems seeking past end of file */
  99   /* Test ftell beyond end of file.  */
 100   ASSERT (fseek (stdin, 0, SEEK_END) == 0);
 101   ch = ftell (stdin);
 102   ASSERT (fseek (stdin, 10, SEEK_END) == 0);
 103   ASSERT (ftell (stdin) == ch + 10);
 104 #endif
 105
 106   return 0;
 107 }