// Match image file path r := regexp.MustCompile(`\!\[.+?\]\(([^\s\)]+).*\)`) match := r.FindAllStringSubmatch(content, -1) // Image Tag Pattern //  //  // [](リンクURL) // regexp result sample // match => [[ /image/hoge/fuga.jpg] [ /image/hoge/fuga.jpg] ....] // match[0] => [ /image/hoge/fuga.jpg] // match[0][0] =>  // match[0][1] => /image/hoge/fuga.jpg