libio/bug-mmap-fflush.c

   1 /* Test for bug in fflush synchronization behavior.  */
   2
   3 #include <stdio.h>
   4 #include <stdlib.h>
   5 #include <string.h>
   6
   7
   8 static char *fname;
   9
  10 static void prepare (void);
  11 #define PREPARE(argc, argv) prepare ()
  12
  13
  14 #define TEST_FUNCTION do_test ()
  15 static int do_test (void);
  16 #include "../test-skeleton.c"
  17
  18
  19 static void
  20 prepare (void)
  21 {
  22   int fd = create_temp_file ("bug-mmap-fflush.", &fname);
  23   if (fd == -1)
  24     exit (3);
  25   /* We don't need the descriptor.  */
  26   close (fd);
  27 }
  28
  29
  30 static int
  31 do_test (void)
  32 {
  33   FILE *f;
  34   off_t o;
  35   char buffer[1024];
  36
  37   snprintf (buffer, sizeof (buffer), "echo 'From foo@bar.com' > %s", fname);
  38   system (buffer);
  39   f = fopen (fname, "r");
  40   fseek (f, 0, SEEK_END);
  41   o = ftello (f);
  42   fseek (f, 0, SEEK_SET);
  43   fflush (f);
  44   snprintf (buffer, sizeof (buffer), "echo 'From bar@baz.edu' >> %s", fname);
  45   system (buffer);
  46   fseek (f, o, SEEK_SET);
  47   if (fgets (buffer, 1024, f) == NULL)
  48     exit (1);
  49   if (strncmp (buffer, "From ", 5) != 0)
  50     exit (1);
  51   fclose (f);
  52   exit (0);
  53 }