libio/bug-ungetc3.c

   1 /* Test program for ungetc/ftell interaction bug.  */
   2
   3 #include <stdio.h>
   4
   5 #include <support/xunistd.h>
   6
   7 static void do_prepare (void);
   8 #define PREPARE(argc, argv) do_prepare ()
   9 static int do_test (void);
  10 #define TEST_FUNCTION do_test ()
  11 #include "../test-skeleton.c"
  12
  13 static const char pattern[] = "12345";
  14 static char *temp_file;
  15
  16 static void
  17 do_prepare (void)
  18 {
  19   int fd = create_temp_file ("bug-ungetc.", &temp_file);
  20   if (fd == -1)
  21     {
  22       printf ("cannot create temporary file: %m\n");
  23       exit (1);
  24     }
  25   xwrite (fd, pattern, sizeof (pattern));
  26   close (fd);
  27 }
  28
  29 static int
  30 do_one_test (int mode)
  31 {
  32   FILE *f;
  33
  34   f = fopen (temp_file, "r");
  35   if (f == NULL)
  36     {
  37       printf ("could not open temporary file: %m\n");
  38       return 1;
  39     }
  40
  41   if (mode == 1 && ftell (f) != 0)
  42     {
  43       printf ("first ftell returned wrong position %ld\n", ftell (f));
  44       return 1;
  45     }
  46
  47   if (fgetc (f) != '1' || fgetc (f) != '2')
  48     {
  49       puts ("fgetc failed");
  50       return 1;
  51     }
  52
  53   if (mode == 2 && ftell (f) != 2)
  54     {
  55       printf ("second ftell returned wrong position %ld\n", ftell (f));
  56       return 1;
  57     }
  58
  59   if (ungetc ('6', f) != '6')
  60     {
  61       puts ("ungetc failed");
  62       return 1;
  63     }
  64
  65   if (ftell (f) != 1)
  66     {
  67       printf ("third ftell returned wrong position %ld\n", ftell (f));
  68       return 1;
  69     }
  70
  71   if (fgetc (f) != '6')
  72     {
  73       puts ("fgetc failed");
  74       return 1;
  75     }
  76
  77   if (ftell (f) != 2)
  78     {
  79       printf ("fourth ftell returned wrong position %ld\n", ftell (f));
  80       return 1;
  81     }
  82
  83   fclose (f);
  84
  85   return 0;
  86 }
  87
  88 static int
  89 do_test (void)
  90 {
  91   int mode;
  92   for (mode = 0; mode <= 2; mode++)
  93     if (do_one_test (mode))
  94       return 1;
  95   return 0;
  96 }