'use strict';
const shebangRegex = require('shebang-regex');

module.exports = (string = '') => {
    const match = string.match(shebangRegex);

    if (!match) {
        return null;
    }

    const [path, argument] = match[0].replace(/#! ?/, '').split(' ');
    const binary = path.split('/').pop();

    if (binary === 'env') {
        return argument;
    }

    return argument ? `${binary} ${argument}` : binary;
};