stdio-common/tst-ungetc.c

   1 /* Test for ungetc bugs.  */
   2
   3 #include <stdio.h>
   4 #include <stdlib.h>
   5 #include <unistd.h>
   6
   7 #undef assert
   8 #define assert(x) \
   9   if (!(x)) \
  10     { \
  11       fputs ("test failed: " #x "\n", stderr); \
  12       retval = 1; \
  13       goto the_end; \
  14     }
  15
  16 int
  17 main (int argc, char *argv[])
  18 {
  19   char name[] = "/tmp/tst-ungetc.XXXXXX";
  20   FILE *fp = NULL;
  21   int retval = 0;
  22   int c;
  23   char buffer[64];
  24
  25   int fd = mkstemp (name);
  26   if (fd == -1)
  27     {
  28       printf ("mkstemp failed: %m\n");
  29       return 1;
  30     }
  31   close (fd);
  32   fp = fopen (name, "w");
  33   assert (fp != NULL)
  34   fputs ("bla", fp);
  35   fclose (fp);
  36   fp = NULL;
  37
  38   fp = fopen (name, "r");
  39   assert (fp != NULL);
  40   assert (ungetc ('z', fp) == 'z');
  41   assert (getc (fp) == 'z');
  42   assert (getc (fp) == 'b');
  43   assert (getc (fp) == 'l');
  44   assert (ungetc ('m', fp) == 'm');
  45   assert (getc (fp) == 'm');
  46   assert ((c = getc (fp)) == 'a');
  47   assert (getc (fp) == EOF);
  48   assert (ungetc (c, fp) == c);
  49   assert (feof (fp) == 0);
  50   assert (getc (fp) == c);
  51   assert (getc (fp) == EOF);
  52   fclose (fp);
  53   fp = NULL;
  54
  55   fp = fopen (name, "r");
  56   assert (fp != NULL);
  57   assert (getc (fp) == 'b');
  58   assert (getc (fp) == 'l');
  59   assert (ungetc ('b', fp) == 'b');
  60   assert (fread (buffer, 1, 64, fp) == 2);
  61   assert (buffer[0] == 'b');
  62   assert (buffer[1] == 'a');
  63
  64 the_end:
  65   if (fp != NULL)
  66     fclose (fp);
  67   unlink (name);
  68
  69   return retval;
  70 }