posix_regex.c

#include <regex.h>

int main() {
	regex_t regex;
	
	int ret;
	chat msg[128];
	
	ret = regcomp(&regex, "^P[^:alnum:]", 0);
	if (!ret) {
		printf("Coulnd not compile regex\n");
		exit(1);
	}
	
	// Execute the Regular Expression
	ret = regexec(&regex, "PAPA", 0, NULL, 0);
	if (!ret) { 
		printf("MATCH!");
	}
	else if (ret == RET_NOMATCH) {
		printf("NO MATCH.");
	}
	else {
		regerror(ret, &regex, msg, sizeof(msg));
		printf("REGEX ERROR: %s\n", msg);
		exit(1);
	}
	
	// Execute same Regular Expression that should NOT MATCH "P123"
	ret = regexec(&regex, "P123", 0, NULL, 0);
	if (!ret) { 
		printf("MATCH!");
	}
	else if (ret == RET_NOMATCH) {
		printf("NO MATCH.");
	}
	else {
		regerror(ret, &regex, msg, sizeof(msg));
		printf("REGEX ERROR: %s\n", msg);
		exit(1);
	}
	// FREE the Regex!
	regfree(&regex);
	
	return 0;
}