memcheck/tests/stpncpy.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3
   4 #define _GNU_SOURCE
   5 #include <string.h>
   6
   7 int main(int argc, char **argv)
   8 {
   9   char a[] = "The spazzy orange tiger jumped over the tawny jaguar.";
  10   char *b, *c;
  11   char *d, *e;
  12
  13   size_t l = strlen (a);
  14   fprintf (stderr, "strlen: %zd\n", l); // strlen: 53
  15
  16   b = (char *) malloc((l + 3)); // Extra space for some zeros.
  17   b[l] = 'X';
  18   b[l + 1] = 'X';
  19   b[l + 2] = 'X';
  20   c = stpncpy (b, a, l + 3);
  21
  22   fprintf (stderr, "equal: %d\n", strcmp (a, b)); // equal: 0
  23   fprintf (stderr, "retlen: %zd\n", c - b); // retlen: 53
  24   fprintf (stderr, "last: '%c'\n", *(c - 1)); // last: '.'
  25   fprintf (stderr, "zero0: %d\n", *c); // zero0: 0
  26   fprintf (stderr, "zero1: %d\n", *(c + 1)); // zero1: 0
  27   fprintf (stderr, "zero2: %d\n", *(c + 2)); // zero2: 0
  28
  29   d = (char *) malloc (l - 1); // No room for zero termination or dot.
  30   e = stpncpy (d, b, l - 1);
  31
  32   fprintf (stderr, "equal: %d\n", strncmp (b, d, l - 1)); // equal: 0
  33   fprintf (stderr, "retlen: %zd\n", e - d); // retlen: 52
  34   fprintf (stderr, "last: '%c'\n", *(e - 1)); // last: 'r'
  35
  36   free (b);
  37   free (d);
  38   return 0;
  39 }