Back to index

glibc  2.9
test-fseek.c
Go to the documentation of this file.
00001 /* Copyright (C) 1991, 1992, 1996, 1997 Free Software Foundation, Inc.
00002    This file is part of the GNU C Library.
00003 
00004    The GNU C Library is free software; you can redistribute it and/or
00005    modify it under the terms of the GNU Lesser General Public
00006    License as published by the Free Software Foundation; either
00007    version 2.1 of the License, or (at your option) any later version.
00008 
00009    The GNU C Library is distributed in the hope that it will be useful,
00010    but WITHOUT ANY WARRANTY; without even the implied warranty of
00011    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00012    Lesser General Public License for more details.
00013 
00014    You should have received a copy of the GNU Lesser General Public
00015    License along with the GNU C Library; if not, write to the Free
00016    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
00017    02111-1307 USA.  */
00018 
00019 #include <stdio.h>
00020 
00021 #define TESTFILE "/tmp/test.dat"
00022 
00023 int
00024 main (void)
00025 {
00026   FILE *fp;
00027   int i, j;
00028 
00029   puts ("\nFile seek test");
00030   fp = fopen (TESTFILE, "w");
00031   if (fp == NULL)
00032     {
00033       perror (TESTFILE);
00034       return 1;
00035     }
00036 
00037   for (i = 0; i < 256; i++)
00038     putc (i, fp);
00039   if (freopen (TESTFILE, "r", fp) != fp)
00040     {
00041       perror ("Cannot open file for reading");
00042       return 1;
00043     }
00044 
00045   for (i = 1; i <= 255; i++)
00046     {
00047       printf ("%3d\n", i);
00048       fseek (fp, (long) -i, SEEK_END);
00049       if ((j = getc (fp)) != 256 - i)
00050        {
00051          printf ("SEEK_END failed %d\n", j);
00052          break;
00053        }
00054       if (fseek (fp, (long) i, SEEK_SET))
00055        {
00056          puts ("Cannot SEEK_SET");
00057          break;
00058        }
00059       if ((j = getc (fp)) != i)
00060        {
00061          printf ("SEEK_SET failed %d\n", j);
00062          break;
00063        }
00064       if (fseek (fp, (long) i, SEEK_SET))
00065        {
00066          puts ("Cannot SEEK_SET");
00067          break;
00068        }
00069       if (fseek (fp, (long) (i >= 128 ? -128 : 128), SEEK_CUR))
00070        {
00071          puts ("Cannot SEEK_CUR");
00072          break;
00073        }
00074       if ((j = getc (fp)) != (i >= 128 ? i - 128 : i + 128))
00075        {
00076          printf ("SEEK_CUR failed %d\n", j);
00077          break;
00078        }
00079     }
00080   fclose (fp);
00081   remove (TESTFILE);
00082 
00083   puts ((i > 255) ? "Test succeeded." : "Test FAILED!");
00084   return (i > 255) ? 0 : 1;
00085 }