foo.c

#include <regex.h>
#include <stdlib.h>

int foo() {
  const char *target_string = "hello wasm";
  const char *pattern = "wasm";

  regex_t regex_compiled;
  int return_code;

  if (regcomp(&regex_compiled, pattern, REG_EXTENDED)) {
    return 1; // Return 1 if the regex failed to compile
  }

  return_code = regexec(&regex_compiled, target_string, 0, NULL, 0);

  regfree(&regex_compiled); // Free up the memory allocated for the regex

  if (!return_code) {
    return 0; // Return 0 if the pattern is found in the target_string
  } else if (return_code == REG_NOMATCH) {
    return 2; // Return 2 if the pattern is not found
  } else {
    return 3; // Return 3 for any other type of error
  }
}