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#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
static char *fname;
static void do_prepare (void);
#define PREPARE(argc, argv) do_prepare ()
static int do_test (void);
#define TEST_FUNCTION do_test ()
#include <test-skeleton.c>
static void
do_prepare (void)
{
static const char pattern[] = "12345678901234567890";
int fd = create_temp_file ("bug-fseek.", &fname);
if (fd == -1)
{
printf ("cannot create temporary file: %m\n");
exit (1);
}
if (write (fd, pattern, sizeof (pattern)) != sizeof (pattern))
{
perror ("short write");
abort ();
}
close (fd);
}
static int
do_test (void)
{
FILE *f;
int result = 0;
char buf[10];
if ((f = fopen (fname, "r")) == (FILE *) NULL)
{
perror ("fopen(\"r\")");
}
fread (buf, 3, 1, f);
errno = 0;
if (fseek (f, -10, SEEK_CUR) == 0)
{
printf ("fseek() for r to before start of file worked!\n");
result = 1;
}
else if (errno != EINVAL)
{
printf ("\
fseek() for r to before start of file did not set errno to EINVAL. \
Got %d instead\n",
errno);
result = 1;
}
fclose (f);
if ((f = fopen (fname, "r+")) == (FILE *) NULL)
{
perror ("fopen(\"r+\")");
}
fread (buf, 3, 1, f);
errno = 0;
if (fseek (f, -10, SEEK_CUR) == 0)
{
printf ("fseek() for r+ to before start of file worked!\n");
result = 1;
}
else if (errno != EINVAL)
{
printf ("\
fseek() for r+ to before start of file did not set errno to EINVAL. \
Got %d instead\n",
errno);
result = 1;
}
fclose (f);
return result;
}
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