Regular expression needs an extra whitespace at the end - c

Question

Consider this code:
#include <pcre.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
int main(int argc, char **argv) {
char **ret = NULL, **t;
char *buffer;
pcre *re;
const char *error;
int erroffset, rc = 1, arraylength = 0, ovector[2], i = 0;
const char *string = "WORD";
buffer = malloc(strlen(string)+1);
re = pcre_compile("[A-Za-z0-9]+|\\\"[A-Za-z0-9\\s\\.'\\?]+\\\"", PCRE_MULTILINE, &error, &erroffset, NULL);
if (re == NULL ) printf ("pcre_compile error: %s\n", error);
while (rc > 0) {
rc = pcre_exec(re, NULL, string, strlen(string), i, 0, ovector, 2);
bzero(buffer, strlen(string));
pcre_copy_substring(string, ovector, rc, 0, buffer, strlen(string));
if (rc > 0) {
printf("BUFFER: %s\n", buffer);
}
i = ovector[1];
}
return 0;
}
The output of this is:
[bart#localhost tests]$ ./pcre
BUFFER:
I expect to get WORD. When I added a whitespace character after WORD:
const char *string = "WORD ";
it does work:
[bart#localhost tests]$ ./pcre
BUFFER: WORD
Also, when I add more words, it works.
I tried to test my regular expression here, and it tells me it should work without the whitespace character.
What am I missing here?
Update When I change my regex to [A-Za-z0-9]+ it still doesn't work without the whitespace.

Answer 1

The problem was in pcre_copy_substring, the buffer was too small. This:
pcre_copy_substring(string, ovector, rc, 0, buffer, strlen(string)+1);
fixed it.