ubuntu-buildroot/output/build/host-m4-1.4.19/tests/test-freading.c

131 lines
4.6 KiB
C

/* Test of freading() function.
Copyright (C) 2007-2021 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 <https://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 "freading.h"
#include <stdio.h>
#include "macros.h"
#define TESTFILE "t-freading.tmp"
int
main (void)
{
FILE *fp;
/* Create a file with some contents. Write-only file is never reading. */
fp = fopen (TESTFILE, "w");
ASSERT (fp);
ASSERT (!freading (fp));
ASSERT (fwrite ("foobarsh", 1, 8, fp) == 8);
ASSERT (!freading (fp));
ASSERT (fclose (fp) == 0);
/* Open it in read-only mode. Read-only file is always reading. */
fp = fopen (TESTFILE, "r");
ASSERT (fp);
ASSERT (freading (fp));
ASSERT (fgetc (fp) == 'f');
ASSERT (freading (fp));
ASSERT (fseek (fp, 2, SEEK_CUR) == 0);
ASSERT (freading (fp));
ASSERT (fgetc (fp) == 'b');
ASSERT (freading (fp));
fflush (fp);
ASSERT (freading (fp));
ASSERT (fgetc (fp) == 'a');
ASSERT (freading (fp));
ASSERT (fseek (fp, 0, SEEK_END) == 0);
ASSERT (freading (fp));
ASSERT (fclose (fp) == 0);
/* Open it in read-write mode. POSIX requires a reposition (fseek,
fsetpos, rewind) or EOF when transitioning from read to write;
freading is only deterministic after input or output, but this
test case should be portable even on open, after reposition, and
at EOF. */
/* First a scenario with only fgetc, fseek, fputc. */
fp = fopen (TESTFILE, "r+");
ASSERT (fp);
ASSERT (!freading (fp));
ASSERT (fgetc (fp) == 'f');
ASSERT (freading (fp));
ASSERT (fseek (fp, 2, SEEK_CUR) == 0);
/* freading (fp) is undefined here, but fwriting (fp) is false. */
ASSERT (fgetc (fp) == 'b');
ASSERT (freading (fp));
/* This fseek call is necessary when switching from reading to writing.
See the description of fopen(), ISO C 99 7.19.5.3.(6). */
ASSERT (fseek (fp, 0, SEEK_CUR) == 0);
/* freading (fp) is undefined here, but fwriting (fp) is false. */
ASSERT (fputc ('x', fp) == 'x');
ASSERT (!freading (fp));
ASSERT (fseek (fp, 0, SEEK_END) == 0);
/* freading (fp) is undefined here, because on some implementations (e.g.
glibc) fseek causes a buffer to be read.
fwriting (fp) is undefined as well. */
ASSERT (fclose (fp) == 0);
/* Open it in read-write mode. POSIX requires a reposition (fseek,
fsetpos, rewind) or EOF when transitioning from read to write;
freading is only deterministic after input or output, but this
test case should be portable even on open, after reposition, and
at EOF. */
/* Here a scenario that includes fflush. */
fp = fopen (TESTFILE, "r+");
ASSERT (fp);
ASSERT (!freading (fp));
ASSERT (fgetc (fp) == 'f');
ASSERT (freading (fp));
ASSERT (fseek (fp, 2, SEEK_CUR) == 0);
/* freading (fp) is undefined here, but fwriting (fp) is false. */
ASSERT (fgetc (fp) == 'b');
ASSERT (freading (fp));
fflush (fp);
/* freading (fp) is undefined here, but fwriting (fp) is false. */
ASSERT (fgetc (fp) == 'x');
ASSERT (freading (fp));
/* This fseek call is necessary when switching from reading to writing.
See the description of fopen(), ISO C 99 7.19.5.3.(6). */
ASSERT (fseek (fp, 0, SEEK_CUR) == 0);
/* freading (fp) is undefined here, but fwriting (fp) is false. */
ASSERT (fputc ('z', fp) == 'z');
ASSERT (!freading (fp));
ASSERT (fseek (fp, 0, SEEK_END) == 0);
/* freading (fp) is undefined here, because on some implementations (e.g.
glibc) fseek causes a buffer to be read.
fwriting (fp) is undefined as well. */
ASSERT (fclose (fp) == 0);
/* Open it in append mode. Write-only file is never reading. */
fp = fopen (TESTFILE, "a");
ASSERT (fp);
ASSERT (!freading (fp));
ASSERT (fwrite ("bla", 1, 3, fp) == 3);
ASSERT (!freading (fp));
ASSERT (fclose (fp) == 0);
ASSERT (remove (TESTFILE) == 0);
return 0;
}