// spawn a child process and execute shell command
// author Hitesh Nagda
// version: 0.1.0 (2013/02/01)


// execute a single shell command where "cmd" is a string
exports.exec = function (cmd, cb) {
    // this would be way easier on a shell/bash script :P
    var child_process = require('child_process');
    var parts = cmd.split(/\s+/g);
    var p = child_process.spawn(parts[0], parts.slice(1), { stdio: 'inherit' });
    p.on('exit', function (code) {
        var err = null;
        if (code) {
            err = new Error('command "' + cmd + '" exited with wrong status code "' + code + '"');
            err.code = code;
            err.cmd = cmd;
        }
        if (cb) cb(err);
    });
};


// execute multiple commands in series
// this could be replaced by any flow control lib
exports.series = function (cmds, cb) {
    var execNext = function () {
        exports.exec(cmds.shift(), function (err) {
            if (err) {
                cb(err);
            } else {
                if (cmds.length) execNext();
                else cb(null);
            }
        });
    };
    execNext();
};