1: /* Test program for ungetc/ftell interaction bug.  */
    2: 
    3: #include <stdio.h>
    4: 
    5: static void do_prepare (void);
    6: #define PREPARE(argc, argv) do_prepare ()
    7: static int do_test (void);
    8: #define TEST_FUNCTION do_test ()
    9: #include <test-skeleton.c>
   10: 
   11: static const char pattern[] = "12345";
   12: static char *temp_file;
   13: 
   14: static void
   15: do_prepare (void)
   16: {
   17:   int fd = create_temp_file ("bug-ungetc.", &temp_file);
   18:   if (fd == -1)
   19:     {
   20:       printf ("cannot create temporary file: %m\n");
   21:       exit (1);
   22:     }
   23:   write (fd, pattern, sizeof (pattern));
   24:   close (fd);
   25: }
   26: 
   27: static int
   28: do_test (void)
   29: {
   30:   int i;
   31:   FILE *f;
   32:   char buf[10];
   33:   long offset, diff;
   34:   int result = 0;
   35: 
   36:   f = fopen (temp_file, "rw");
   37: 
   38:   rewind (f);
   39:   for (i = 0; i < 3; i++)
   40:     printf ("%c\n", getc (f));
   41:   offset = ftell (f);
   42:   printf ("offset = %ld\n", offset);
   43:   if (ungetc ('4', f) != '4')
   44:     {
   45:       printf ("ungetc failed\n");
   46:       abort ();
   47:     }
   48:   printf ("offset after ungetc = %ld\n", ftell (f));
   49: 
   50:   i = fread ((void *) buf, 4, (size_t) 1, f);
   51:   printf ("read %d (%c), offset = %ld\n", i, buf[0], ftell (f));
   52:   diff = ftell (f) - offset;
   53:   if (diff != 3)
   54:     {
   55:       printf ("ftell did not update properly.  got %ld, expected 3\n", diff);
   56:       result = 1;
   57:     }
   58:   fclose (f);
   59: 
   60:   return result;
   61: }