memcheck/tests/memccpy2.c

   1 #include <ctype.h>
   2 #include <stdio.h>
   3 #include <string.h>
   4 #include <assert.h>
   5 #include <stdlib.h>
   6
   7 int main(void)
   8 {
   9    char* astring = strdup("this is a string # with something to seek");
  10    size_t len = strlen(astring);
  11    memccpy(astring+10, astring, '#', len-10);
  12    sprintf(astring, "this is a string # with something to seek");
  13    memccpy(astring, astring+10, '#', len);
  14
  15    sprintf(astring, "this is a string # with something to seek");
  16    /*
  17     * space is earlier than len, no overlap
  18     * "this " gets copied (up to and including the first ' ')
  19     * and it overwrites the destination starting with the 's' of "string"
  20     * so res will point to the 'g' of "string"
  21     */
  22    char* res = memccpy(astring+10, astring, ' ', len-10);
  23    assert(res && *res == 'g');
  24    sprintf(astring, "this is a string # with something to seek");
  25    /* length is 0, nothing copied, returns NULL */
  26    res = memccpy(astring, "abcdefhhijklmnopqrstuvwxy", 'z', 0);
  27    assert(NULL == res);
  28    /* 'z' not found so 20 bytes copied, returns NULL */
  29    res = memccpy(astring, "abcdefhhijklmnopqrstuvwxy", 'z', 20);
  30    assert(NULL == res);
  31    free(astring);
  32 }
  33