libio/bug-ungetc3.c

   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_one_test (int mode)
  29 {
  30   FILE *f;
  31
  32   f = fopen (temp_file, "r");
  33   if (f == NULL)
  34     {
  35       printf ("could not open temporary file: %m\n");
  36       return 1;
  37     }
  38
  39   if (mode == 1 && ftell (f) != 0)
  40     {
  41       printf ("first ftell returned wrong position %ld\n", ftell (f));
  42       return 1;
  43     }
  44
  45   if (fgetc (f) != '1' || fgetc (f) != '2')
  46     {
  47       puts ("fgetc failed");
  48       return 1;
  49     }
  50
  51   if (mode == 2 && ftell (f) != 2)
  52     {
  53       printf ("second ftell returned wrong position %ld\n", ftell (f));
  54       return 1;
  55     }
  56
  57   if (ungetc ('6', f) != '6')
  58     {
  59       puts ("ungetc failed");
  60       return 1;
  61     }
  62
  63   if (ftell (f) != 1)
  64     {
  65       printf ("third ftell returned wrong position %ld\n", ftell (f));
  66       return 1;
  67     }
  68
  69   if (fgetc (f) != '6')
  70     {
  71       puts ("fgetc failed");
  72       return 1;
  73     }
  74
  75   if (ftell (f) != 2)
  76     {
  77       printf ("fourth ftell returned wrong position %ld\n", ftell (f));
  78       return 1;
  79     }
  80
  81   fclose (f);
  82
  83   return 0;
  84 }
  85
  86 static int
  87 do_test (void)
  88 {
  89   int mode;
  90   for (mode = 0; mode <= 2; mode++)
  91     if (do_one_test (mode))
  92       return 1;
  93   return 0;
  94 }