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  }