pslook.js~

var exec = require('child_process').exec,
		fs = require('fs'),
    child;

// Default options
var defaultOptions={
	datas:[],
	match:'*',
};

// List running processes
function ls(callback, options) {
	if('function' !== typeof callback) {
		throw Error('No callback given, or given callback is not a function.')
	}
	if(!options) {
		options=defaultOptions;
	}
	fs.readdir('/proc', function(err, files) {
	  err&&callback(err)||files.forEach(function(file){
	  	// Test if the file is a pid
			if(/^[0-9]+$/.test(file)) {
				// if the user just want the pid and do no grep
				if(0===options.datas.length) {
					callback(null,{'pid':parseInt(file,10)});
				// else reading other datas
				} else {
					read(file,callback,options);
				}
			}
		});
	});
}

// Read details on a particular process
function read(pid, callback, options) {
	var process={'pid':pid}, foundDatas=0;
	if(!options) {
		options=defaultOptions;
	}
	if(!(options.datas&&options.datas instanceof Array&&options.datas.length)) {
		callback(Error('No datas asked.'));
	}
	// discount data retrieves
	function dataFound() {
		if(--foundDatas===0)
			callback(null,process);
	}
	// Reading the command line
	if(-1!==options.datas.indexOf('cmdline')) {
		foundDatas++;
		fs.readFile('/proc/'+pid+'/cmdline', 'utf8', function (err, data) {
			if(err) {
			 err&&callback(err);
			} else {
				process.cmdline=data.split('\u0000');
				if(''===process.cmdline[process.cmdline.length-1]) {
					process.cmdline.pop();
				}
				dataFound();
			}
		});
	}
	// Reading the env vars
	if(-1!==options.datas.indexOf('environ')) {
		foundDatas++;
		fs.readFile('/proc/'+pid+'/environ', 'utf8', function (err, data) {
			if(err) {
			 err&&callback(err);
			} else {
				process.env={};
				data.split('\u0000').forEach(function(env){
					var vals;
					if(env) {
						vals=env.split('=');
						process.env[vals[0]]=vals[1];
					}
				});
				dataFound();
			}
		});
	}
	// Reading the process cwd
	if(-1!==options.datas.indexOf('cwd')) {
		foundDatas++;
		fs.readlink('/proc/'+pid+'/cwd', function (err, data) {
			if(err) {
			 err&&callback(err);
			} else {
				process.cwd=data;
				dataFound();
			}
		});
	}
	// Reading the process stat
	if(-1!==options.datas.indexOf('stat')) {
		foundDatas++;
		fs.readFile('/proc/'+pid+'/stat', 'utf8', function (err, data) {
			if (err) throw err;
			var fields=data.split(/[\r\n\s]+/);
			process.stat={
				'command':fields[1],
				'state':fields[2],
				'ppid': parseInt(fields[3],10),
				'pgrp': parseInt(fields[4],10),
				'session': parseInt(fields[5],10),
				'tty_nr': parseInt(fields[6],10),
				'tpgid': parseInt(fields[7],10),
				'flags': parseInt(fields[8],10),
				'minflt': parseInt(fields[9],10),
				'cminflt': parseInt(fields[10],10),
				'majflt': parseInt(fields[11],10),
				'cmajflt': parseInt(fields[12],10),
				'utime': parseInt(fields[13],10),
				'stime': parseInt(fields[14],10),
				'cutime': parseInt(fields[15],10),
				'cstime': parseInt(fields[16],10),
				'priority': parseInt(fields[17],10),
				'nice': parseInt(fields[18],10),
				'numThreads': parseInt(fields[19],10),
				'itrealvalue': parseInt(fields[20],10),
				'startTime': parseInt(fields[21],10),
				'vsize': parseInt(fields[22],10),
				'rss': parseInt(fields[23],10),
				'rsslim': parseInt(fields[24],10),
				'startCode': parseInt(fields[25],10),
				'endCode': parseInt(fields[26],10),
				'startStack': parseInt(fields[27],10),
				'kstkesp': parseInt(fields[28],10),
				'kstkeip': parseInt(fields[29],10),
				'signal': parseInt(fields[30],10),
				'blocked': parseInt(fields[31],10),
				'sigignore': parseInt(fields[32],10),
				'sigcatch': parseInt(fields[33],10),
				'wchan': parseInt(fields[34],10),
				'nswap': parseInt(fields[35],10),
				'cnswap': parseInt(fields[36],10),
				'exitSignal': parseInt(fields[37],10),
				'processor': parseInt(fields[38],10),
				'rtPriority': parseInt(fields[39],10),
				'policy': parseInt(fields[40],10),
				'delaycctBlkioTicks': parseInt(fields[41],10),
				'guestTime': parseInt(fields[42],10),
				'cguestTime': parseInt(fields[43],10),
			}
			dataFound();
		});
	}
	// Reading the process statm
	if(-1!==options.datas.indexOf('statm')) {
		foundDatas++;
		fs.readFile('/proc/'+pid+'/statm', 'utf8', function (err, data) {
			if (err) throw err;
			var fields=data.split(/[\r\n\s]+/);
			process.statm={
				'size': fields[1],
				'resident': fields[2],
				'share': parseInt(fields[3],10),
				'text': parseInt(fields[4],10),
				'lib': parseInt(fields[5],10),
				'data': parseInt(fields[5],10),
				'dt': parseInt(fields[5],10)
			}
			dataFound();
		});
	}
	// Checking datas integrity
	if(options.datas.length!==foundDatas) {
		callback(Error('Asked unknow datas.'))
	}
}

/*ls(function(err, process) {
	console.log(process);
}, {datas: ['cmdline']});*/

read(4535,function(err, process) {
	console.log(process);
}, {datas: ['cmdline','statm','stat','cwd']});