glibc/libio/tst-mmap-offend.c

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/* Test case for bug with mmap stdio read past end of file. */
#include <stdio.h>
#include <error.h>
#include <errno.h>
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 char *temp_file;
static const char text1[] = "hello\n";
static void
do_prepare (void)
{
int temp_fd = create_temp_file ("tst-mmap-offend.", &temp_file);
if (temp_fd == -1)
error (1, errno, "cannot create temporary file");
else
{
ssize_t cc = write (temp_fd, text1, sizeof text1 - 1);
if (cc != sizeof text1 - 1)
error (1, errno, "cannot write to temporary file");
}
close (temp_fd);
}
static int
do_test (void)
{
unsigned char buffer[8192];
int result = 0;
FILE *f = fopen (temp_file, "rm");
size_t cc;
if (f == NULL)
{
perror (temp_file);
return 1;
}
cc = fread (buffer, 1, sizeof (buffer), f);
printf ("fread %zu: \"%.*s\"\n", cc, (int) cc, buffer);
if (cc != sizeof text1 - 1)
{
perror ("fread");
result = 1;
}
if (fseek (f, 2048, SEEK_SET) != 0)
{
perror ("fseek off end");
result = 1;
}
if (fread (buffer, 1, sizeof (buffer), f) != 0
|| ferror (f) || !feof (f))
{
printf ("after fread error %d eof %d\n",
ferror (f), feof (f));
result = 1;
}
printf ("ftell %ld\n", ftell (f));
if (fseek (f, 0, SEEK_SET) != 0)
{
perror ("fseek rewind");
result = 1;
}
cc = fread (buffer, 1, sizeof (buffer), f);
printf ("fread after rewind %zu: \"%.*s\"\n", cc, (int) cc, buffer);
if (cc != sizeof text1 - 1)
{
perror ("fread after rewind");
result = 1;
}
fclose (f);
return result;
}