Kiasyn's Blog

String matching with C++ PCRE

bool regex_match( const char *pattern, const std::string str, std::vector *substrings )
{
	const char *err;
	int erroffset = 0;
	pcre *re = pcre_compile( pattern, 0, &err, &erroffset, NULL );
	int ovector[90];
	size_t rc;
	if ( !re )
	{
		bug( "%s: regular expression compilation failed at: %d: %s", __FUNCTION__, erroffset, err );
		return false;
	}
	if ( ( rc = pcre_exec(re, NULL, str.c_str(), str.length(), 0, 0, ovector, 90 ) ) < 0 )
		switch( rc )
		{
			case PCRE_ERROR_NOMATCH:	return false;
			default:	bug( "%s: Matching error: %d", __FUNCTION__, rc );	return false;
		}
	if ( substrings )
		for ( size_t i = 0; i < rc; i++ )
			substrings->push_back( str.substr( ovector[2*i], ovector[2*i+1] - ovector[2*i] ) );
	return true;
}
bool simple_match( const char *pattern, const char *str )
{
	std::string newPattern = "^";

	for ( size_t i = 0; i < strlen(pattern); i++ )
	{
		if ( !isalnum( pattern[i] ) && !iscntrl(pattern[i]) )
		{
			if ( pattern[i] == '*' )
			{
				newPattern += ".*";
				continue;
			}
			else
				newPattern += '\\';
		}
		newPattern += pattern[i];
	}
	newPattern += "$";
	return regex_match( newPattern.c_str(), str, NULL );
}