Download imgs in markdown files

imgmd.js

var fs = require('fs');
var request = require('sync-request');
var process = require('process');

var prefix = '';

var dirname = process.argv[2];
if(!dirname)
{
	console.log('请指定目录。');
	process.exit(0);
}

try {fs.mkdirSync(dirname + '/img');} catch(ex) {}
var dir= fs.readdirSync(dirname);

for(var i = 0; i < dir.length; i++)
{
	var fname = dir[i];
	if(!fname.endsWith('.md'))
		continue;
	var content = fs.readFileSync(dirname + '/' + fname, 'utf-8');
	var re = /!\[.*?\]\((.+?)\)/g;
	var rms;
	while(rms = re.exec(content))
	{
		try {
		var url = prefix + rms[1];
		if(!url.startsWith('http'))
			continue;
		//console.log('url: ' + url);
		var picname = /\/([\w\-]+\.(?:jpg|png|gif))/i.exec(url)[1];
		var data = request('GET', url).getBody();
		fs.writeFileSync(dirname + '/img/' + picname, data);
		console.log('pic: ' + picname);
		} catch(ex) { console.log('error: ' + ex.toString());}
	}

}