glibc/libio/bug-mmap-fflush.c

54 lines
1011 B
C

/* Test for bug in fflush synchronization behavior. */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
static char *fname;
static void prepare (void);
#define PREPARE(argc, argv) prepare ()
#define TEST_FUNCTION do_test ()
static int do_test (void);
#include "../test-skeleton.c"
static void
prepare (void)
{
int fd = create_temp_file ("bug-mmap-fflush.", &fname);
if (fd == -1)
exit (3);
/* We don't need the descriptor. */
close (fd);
}
static int
do_test (void)
{
FILE *f;
off_t o;
char buffer[1024];
snprintf (buffer, sizeof (buffer), "echo 'From foo@bar.com' > %s", fname);
system (buffer);
f = fopen (fname, "r");
fseek (f, 0, SEEK_END);
o = ftello (f);
fseek (f, 0, SEEK_SET);
fflush (f);
snprintf (buffer, sizeof (buffer), "echo 'From bar@baz.edu' >> %s", fname);
system (buffer);
fseek (f, o, SEEK_SET);
if (fgets (buffer, 1024, f) == NULL)
exit (1);
if (strncmp (buffer, "From ", 5) != 0)
exit (1);
fclose (f);
exit (0);
}