text: /* Test for ungetc bugs.  */
  
  #include <stdio.h>
  #include <unistd.h>
  
  #undef assert
  #define assert(x) \
    if (!(x)) \
      { \
        fputs ("test failed: " #x "\n", stderr); \
        retval = 1; \
        goto the_end; \
      }
  
  int
  main (int argc, char *argv[])
  {
    char *name;
    FILE *fp = NULL;
    int retval = 0;
    int c;
    char buffer[64];
  
    name = tmpnam (NULL);
    fp = fopen (name, "w");
    assert (fp != NULL)
    fputs ("bla", fp);
    fclose (fp);
    fp = NULL;
  
    fp = fopen (name, "r");
    assert (fp != NULL);
    assert (ungetc ('z', fp) == 'z');
    assert (getc (fp) == 'z');
    assert (getc (fp) == 'b');
    assert (getc (fp) == 'l');
    assert (ungetc ('m', fp) == 'm');
    assert (getc (fp) == 'm');
    assert ((c = getc (fp)) == 'a');
    assert (getc (fp) == EOF);
    assert (ungetc (c, fp) == c);
    assert (feof (fp) == 0);
    assert (getc (fp) == c);
    assert (getc (fp) == EOF);
    fclose (fp);
    fp = NULL;
  
    fp = fopen (name, "r");
    assert (fp != NULL);
    assert (getc (fp) == 'b');
    assert (getc (fp) == 'l');
    assert (ungetc ('b', fp) == 'b');
    assert (fread (buffer, 1, 64, fp) == 2);
    assert (buffer[0] == 'b');
    assert (buffer[1] == 'a');
  
  the_end:
    if (fp != NULL)
      fclose (fp);
    unlink (name);
  
    return retval;
  }
  