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 } 40
