Hash :
524d6a2e
Author :
Date :
2009-12-31T11:53:33
stdio: warn on suspicious uses Using gets is almost ALWAYS wrong (it is extremely rare that you have full control over stdin). POSIX 2008 marked it as obsolete, even though C89 requires it. Attach a warning to remind developers. Add a comment to sprintf explaining why it does not get this treatment. Improve the warnings for fseek/fseeko (and ftell/ftello), with comments justifying our position. Some of our unit tests never use large files, so rather than drag in a dependency on fseeko, they should be the first compilation units to use _GL_NO_LARGE_FILES. * modules/stdio (Depends-on): Add warn-on-use. (Makefile.am): Provide new substitutions. * m4/stdio_h.m4 (gl_STDIO_H): Check for inline, ftello, and fseeko. * lib/stdio.in.h (gets): Always warn on use. (fseek, ftell): Adjust when warnings are issued, and honor _GL_NO_LARGE_FILES as a way to silence the warning. * tests/test-fpurge.c [!GNULIB_FSEEK]: Use new means to squelch any warning about large file offsets. * tests/test-freadable.c [!GNULIB_FSEEK]: Likewise. * tests/test-freading.c [!GNULIB_FSEEK]: Likewise. * tests/test-fseeko.c [!GNULIB_FSEEK]: Likewise. * tests/test-ftell.c [!GNULIB_FSEEK]: Likewise. * tests/test-ftello.c [!GNULIB_FSEEK]: Likewise. * tests/test-fwritable.c [!GNULIB_FSEEK]: Likewise. * tests/test-fwriting.c [!GNULIB_FSEEK]: Likewise. * tests/test-getopt.c [!GNULIB_FTELL]: Likewise. Signed-off-by: Eric Blake <ebb9@byu.net>
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/* Test of fwritable() function.
Copyright (C) 2007-2010 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 of the License, 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/>. */
/* Written by Bruno Haible <bruno@clisp.org>, 2007. */
#include <config.h>
/* None of the files accessed by this test are large, so disable the
fseek link warning if we are not using the gnulib fseek module. */
#define _GL_NO_LARGE_FILES
#include "fwritable.h"
#include <stdio.h>
#include "macros.h"
#define TESTFILE "t-fwritable.tmp"
int
main ()
{
FILE *fp;
/* Create a file with some contents. */
fp = fopen (TESTFILE, "w");
if (fp == NULL)
goto skip;
ASSERT (fwritable (fp));
if (fwrite ("foobarsh", 1, 8, fp) < 8)
goto skip;
ASSERT (fwritable (fp));
if (fclose (fp))
goto skip;
/* Open it in read-only mode. */
fp = fopen (TESTFILE, "r");
if (fp == NULL)
goto skip;
ASSERT (!fwritable (fp));
if (fgetc (fp) != 'f')
goto skip;
ASSERT (!fwritable (fp));
if (fseek (fp, 2, SEEK_CUR))
goto skip;
ASSERT (!fwritable (fp));
if (fgetc (fp) != 'b')
goto skip;
ASSERT (!fwritable (fp));
fflush (fp);
ASSERT (!fwritable (fp));
if (fgetc (fp) != 'a')
goto skip;
ASSERT (!fwritable (fp));
if (fseek (fp, 0, SEEK_END))
goto skip;
ASSERT (!fwritable (fp));
if (fclose (fp))
goto skip;
/* Open it in read-write mode. */
fp = fopen (TESTFILE, "r+");
if (fp == NULL)
goto skip;
ASSERT (fwritable (fp));
if (fgetc (fp) != 'f')
goto skip;
ASSERT (fwritable (fp));
if (fseek (fp, 2, SEEK_CUR))
goto skip;
ASSERT (fwritable (fp));
if (fgetc (fp) != 'b')
goto skip;
ASSERT (fwritable (fp));
fflush (fp);
ASSERT (fwritable (fp));
if (fgetc (fp) != 'a')
goto skip;
ASSERT (fwritable (fp));
if (fputc ('z', fp) != 'z')
goto skip;
ASSERT (fwritable (fp));
if (fseek (fp, 0, SEEK_END))
goto skip;
ASSERT (fwritable (fp));
if (fclose (fp))
goto skip;
/* Open it in append mode. */
fp = fopen (TESTFILE, "a");
if (fp == NULL)
goto skip;
ASSERT (fwritable (fp));
if (fwrite ("bla", 1, 3, fp) < 3)
goto skip;
ASSERT (fwritable (fp));
if (fclose (fp))
goto skip;
return 0;
skip:
fprintf (stderr, "Skipping test: file operations failed.\n");
return 77;
}