int regexec(const regex_t *, const char *, size_t, regmatch_t [], int);

typedef struct {
regoff_t rm_so;     // start of match 
regoff_t rm_eo;     // end of match 
} regmatch_t; 

regmatch_t rx_match[100];

char* found[256+1] = {0};
memcpy(found, &text[rx_match[0].rm_so], &text[rx_match[0].rm_so] - &text[rx_match[0].rm_eo]);

#include <stdio.h>
#include <regex.h>

#define BUFSIZE 1000
#define NMATCH 100

int main(void) {
	char buf[BUFSIZE];
	char found[BUFSIZE];			

 	regex_t regexp;
 	regmatch_t rx_match[NMATCH];

 	char *str = "[0-9]+";

 	if (regcomp(&regexp, str, 0)!=0) {
    	return 1;
   	}
 
 	for(;;) {
    	printf("> "); fflush(stdout);
		if ((fgets(buf, BUFSIZE, stdin))==0)
       		return 0;

    	if ((regexec(&regexp, buf, NMATCH, rx_match, 0))==0) {
    	   	printf("Match!!!\n");
			memset(found,'0',BUFSIZE*sizeof(char));
			memcpy(found, &buf[rx_match[0].rm_so], &buf[rx_match[0].rm_so] - &buf[rx_match[0].rm_eo]);
			printf("gefunden: %s\n",found);
    	}
    	else
       		printf("Input doesn't match.\n");
   	}
}

regexec(&regexp, buf, strlen(buf), rx_match, NMATCH);