glibc/stdio-common/errnobug.c

60 lines
1.4 KiB
C

/* Regression test for reported old bug that errno is clobbered
by the first successful output to a stream on an unseekable object.
Copyright (C) 1995-2016 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <errno.h>
#include <stdio.h>
#include <unistd.h>
int
main (void)
{
int fd[2];
FILE *f;
/* Get a stream that cannot seek. */
if (pipe (fd))
{
perror ("pipe");
return 1;
}
f = fdopen (fd[1], "w");
if (f == NULL)
{
perror ("fdopen");
return 1;
}
errno = 0;
if (fputs ("fnord", f) == EOF)
{
perror ("fputs");
return 1;
}
if (errno)
{
perror ("errno gratuitously set -- TEST FAILED");
return 1;
}
puts ("Test succeeded.");
return 0;
}