libio/tst-ungetwc2.c

   1 /* Taken from the Li18nux base test suite.  */
   2
   3 #define _XOPEN_SOURCE 500
   4 #include <locale.h>
   5 #include <stdio.h>
   6 #include <stdlib.h>
   7 #include <unistd.h>
   8 #include <wchar.h>
   9
  10 int
  11 main (void)
  12 {
  13   FILE *fp;
  14   const char *str = "abcdef";
  15   wint_t ret, wc;
  16   char fname[] = "/tmp/tst-ungetwc2.out.XXXXXX";
  17   int fd;
  18   long int pos;
  19   int result = 0;
  20
  21   puts ("This program runs on de_DE.UTF-8 locale.");
  22   if (setlocale (LC_ALL, "de_DE.UTF-8") == NULL)
  23     {
  24       fprintf (stderr, "Err: Cannot run on the de_DE.UTF-8 locale\n");
  25       exit (EXIT_FAILURE);
  26     }
  27
  28   /* Write some characters to `testfile'. */
  29   fd = mkstemp (fname);
  30   if (fd == -1)
  31     {
  32       printf ("cannot open temp file: %m\n");
  33       exit (EXIT_FAILURE);
  34     }
  35   if ((fp = fdopen (fd, "w")) == NULL)
  36     {
  37       fprintf (stderr, "Cannot open 'testfile'.\n");
  38       exit (EXIT_FAILURE);
  39     }
  40   fputs (str, fp);
  41   fclose (fp);
  42
  43   /* Open `testfile'. */
  44   if ((fp = fopen (fname, "r")) == NULL)
  45     {
  46       fprintf (stderr, "Cannot open 'testfile'.");
  47       exit (EXIT_FAILURE);
  48     }
  49
  50   /* Get a character. */
  51   wc = getwc (fp);
  52   pos = ftell (fp);
  53   printf ("After get a character: %ld\n", pos);
  54   if (pos != 1)
  55     result = 1;
  56
  57   /* Unget a character. */
  58   ret = ungetwc (wc, fp);
  59   if (ret == WEOF)
  60     {
  61       fprintf (stderr, "ungetwc() returns NULL.");
  62       exit (EXIT_FAILURE);
  63     }
  64   pos = ftell (fp);
  65   printf ("After unget a character: %ld\n", pos);
  66   if (pos != 0)
  67     result = 1;
  68
  69   /* Reget a character. */
  70   wc = getwc (fp);
  71   pos = ftell (fp);
  72   printf ("After reget a character: %ld\n", pos);
  73   if (pos != 1)
  74     result = 1;
  75
  76   fclose (fp);
  77
  78   unlink (fname);
  79
  80   return result;
  81 }