The idea of the following code is to react to changes in files inside a folder. When I run this code on my macOS everything works as executed.
let fs = require("fs");
let options = {
encoding: 'buffer'
}
fs.watch('.', options, function(eventType, filename) {
if(filename)
{
console.log(filename.toString());
}
});
Inside a Docker Container on the other hand the code does not react to file changes. I run the code in the following way:
docker run -it --rm --name $(basename $(pwd)) -v $(pwd):/app -w /app node:slim sh -c 'node index'
Is there an option to use with Docker to allow system notifications for file changes?
New answer
Initially i advised Gulp (see bottom of the updated post with old answer). It did not worked because you tried to use it programatically, when Gulp is task runner and have own usage patterns, which i did not described. Since you need something specific, i have very simple, surely working solution for you.
It uses one of modules used by gulp called gaze - module which have approx 1.7m downloads per week. Its working, for sure on every system.
npm install gaze --save
To make it work lets create index.js in your root folder (which will be mounted to your app folder inside of the docker, and then just follow basic instruction given in module README:
var gaze = require('gaze');
// Watch all .js files/dirs in process.cwd()
gaze('**/*.js', function(err, watcher) {
// Files have all started watching
// watcher === this
console.log('Watching files...');
// Get all watched files
var watched = this.watched();
// On file changed
this.on('changed', function(filepath) {
console.log(filepath + ' was changed');
});
// On file added
this.on('added', function(filepath) {
console.log(filepath + ' was added');
});
// On file deleted
this.on('deleted', function(filepath) {
console.log(filepath + ' was deleted');
});
// On changed/added/deleted
this.on('all', function(event, filepath) {
console.log(filepath + ' was ' + event);
});
// Get watched files with relative paths
var files = this.relative();
});
Now lets run your command:
docker run -it --rm --name $(basename $(pwd)) -v $(pwd):/app -w /app node sh -c 'node index'
What we have upon changes - Linux outpud, but this works for Mac OS too.
blackstork#linux-uksg:~/WebstormProjects/SO/case1> docker run -it --rm --name $(basename $(pwd)) -v $(pwd):/app -w /app node sh -c 'node index'
Watching files...
/app/bla was changed
/app/foobar.js was changed
Old answer.
You can do it with gulp.
Gulpfile.js
const gulp = require('gulp');
gulp.task( 'watch' , ()=>{
return gulp.watch(['app/**'], ['doStuff']);
});
gulp.task( 'doStuff', cb => {
console.log('stuff');
//do stuff
cb();
});
So far such approach worked for me (of course you can build much more
complex things, but if find using gulp conventient for different
filesystem tasks).
I'm developing a native app using Node webkit. As usually everything goes with JS. what i need is: i want to schedule a task using "schtask" command. so that i need to run it from JS code.Is there any way to run commands from JavaScript code?? or any other alternative to set schedule tasks in windows from Java Script?- Thanks in advance
if you are using node-webkit you can use node-modules like child_process.
Here is a sample code how to run a ls command.
var spawn = require('child_process').spawn, // requiring child_process
ls = spawn('ls', ['-l', '.']); // created a process for ls the arguments in []
ls.stdout.on('data', function (data) {
console.log('stdout: ' + data);
});
Here are the references
I found this answer in google..
It works PERFECT!
var spawn = require('child_process').spawn;
var cp = spawn(process.env.comspec, ['/c', 'command', '-arg1', '-arg2']);
cp.stdout.on("data", function(data) {
console.log(data.toString());
});
cp.stderr.on("data", function(data) {
console.error(data.toString());
});
Thanks for your guidence #Mritunjay :)
I am developing a Gulpfile. Can it be made to restart as soon as it changes? I am developing it in CoffeeScript. Can Gulp watch Gulpfile.coffee in order to restart when changes are saved?
You can create a task that will gulp.watch for gulpfile.js and simply spawn another gulp child_process.
var gulp = require('gulp'),
argv = require('yargs').argv, // for args parsing
spawn = require('child_process').spawn;
gulp.task('log', function() {
console.log('CSSs has been changed');
});
gulp.task('watching-task', function() {
gulp.watch('*.css', ['log']);
});
gulp.task('auto-reload', function() {
var p;
gulp.watch('gulpfile.js', spawnChildren);
spawnChildren();
function spawnChildren(e) {
// kill previous spawned process
if(p) { p.kill(); }
// `spawn` a child `gulp` process linked to the parent `stdio`
p = spawn('gulp', [argv.task], {stdio: 'inherit'});
}
});
I used yargs in order to accept the 'main task' to run once we need to restart. So in order to run this, you would call:
gulp auto-reload --task watching-task
And to test, call either touch gulpfile.js or touch a.css to see the logs.
I created gulper that is gulp.js cli wrapper to restart gulp on gulpfile change.
You can simply replace gulp with gulper.
$ gulper <task-name>
I use a small shell script for this purpose. This works on Windows as well.
Press Ctrl+C to stop the script.
// gulpfile.js
gulp.task('watch', function() {
gulp.watch('gulpfile.js', process.exit);
});
Bash shell script:
# watch.sh
while true; do
gulp watch;
done;
Windows version: watch.bat
#echo off
:label
cmd /c gulp watch
goto label
I was getting a bunch of EADDRINUSE errors with the solution in Caio Cunha's answer. My gulpfile opens a local webserver with connect and LiveReload. It appears the new gulp process briefly coexists with the old one before the older process is killed, so the ports are still in use by the soon-to-die process.
Here's a similar solution which gets around the coexistence problem, (based largely on this):
var gulp = require('gulp');
var spawn = require('child_process').spawn;
gulp.task('gulp-reload', function() {
spawn('gulp', ['watch'], {stdio: 'inherit'});
process.exit();
});
gulp.task('watch', function() {
gulp.watch('gulpfile.js', ['gulp-reload']);
});
That works fairly well, but has one rather serious side-effect: The last gulp process is disconnected from the terminal. So when gulp watch exits, an orphaned gulp process is still running. I haven't been able to work around that problem, the extra gulp process can be killed manually, or just save a syntax error to gulpfile.js.
I've been dealing with the same problem and the solution in my case was actually very simple. Two things.
npm install nodemon -g (or locally if you prefer)
run with cmd or create a script in packages like this:
"dev": "nodemon --watch gulpfile.js --exec gulp"
The just type npm run dev
--watch specifies the file to keep an eye on. --exec says execute next in line and gulp is your default task. Just pass in argument if you want non default task.
Hope it helps.
EDIT : Making it fancy ;)
Now while the first part should achieve what you were after, in my setup I've needed to add a bit more to make it really user friend. What I wanted was
First open the page.
Look for changes in gulpfile.js and restart gulp if there are any
Gulp it up so keep an eye on files, rebuild and hot reload
If you only do what I've said in the first part, it will open the page every time. To fix it, create a gulp task that will open the page. Like this :
gulp.task('open', function(){
return gulp
.src(config.buildDest + '/index.html')
.pipe(plugins.open({
uri: config.url
}));
Then in my main tasks I have :
gulp.task('default', ['dev-open']);
gulp.task('dev-open', function(done){
plugins.sequence('build', 'connect', 'open', 'watch', done);
});
gulp.task('dev', function(done){
plugins.sequence('build', 'connect', 'watch', done);
});
Then modifying your npm scripts to
"dev": "gulp open & nodemon --watch gulpfile.js --watch webpack.config.js --exec gulp dev"
Will give you exactly what you want. First open the page and then just keep live reloading. Btw for livereload I use the one that comes with connect which always uses the same port. Hope it works for you, enjoy!
Another solution for this is to refresh the require.cache.
var gulp = require('gulp');
var __filenameTasks = ['lint', 'css', 'jade'];
var watcher = gulp.watch(__filename).once('change', function(){
watcher.end(); // we haven't re-required the file yet
// so is the old watcher
delete require.cache[__filename];
require(__filename);
process.nextTick(function(){
gulp.start(__filenameTasks);
});
});
I know this is a very old question, but it's a top comment on Google, so still very relevant.
Here is an easier way, if your source gulpfile.js is in a different directory than the one in use. (That's important!) It uses the gulp modules gulp-newer and gulp-data.
var gulp = require('gulp' )
, data = require('gulp-data' )
, newer = require('gulp-newer' )
, child_process = require('child_process')
;
gulp.task( 'gulpfile.js' , function() {
return gulp.src( 'sources/gulpfile.js' ) // source
.pipe( newer( '.' ) ) // check
.pipe( gulp.dest( '.' ) ) // write
.pipe( data( function(file) { // reboot
console.log('gulpfile.js changed! Restarting gulp...') ;
var t , args = process.argv ;
while ( args.shift().substr(-4) !== 'gulp' ) { t=args; }
child_process.spawn( 'gulp' , args , { stdio: 'inherit' } ) ;
return process.exit() ;
} ) )
;
} ) ;
It works like this:
Trick 1: gulp-newer only executes the following pipes, if the source file is newer than the current one. This way we make sure, there's no reboot-loop.
The while loop removes everything before and including the gulp command from the command string, so we can pass through any arguments.
child_process.spawn spawns a new gulp process, piping input output and error to the parent.
Trick 2: process.exit kills the current process. However, the process will wait to die until the child process is finished.
There are many other ways of inserting the restart function into the pipes.
I just happen to use gulp-data in every of my gulpfiles anyway. Feel free to comment your own solution. :)
Here's another version of #CaioToOn's reload code that is more in line with normal Gulp task procedure. It also does not depend on yargs.
Require spawn and initilaize the process variable (yargs is not needed):
var spawn = require('child_process').spawn;
var p;
The default gulp task will be the spawner:
gulp.task('default', function() {
if(p) { p.kill(); }
// Note: The 'watch' is the new name of your normally-default gulp task. Substitute if needed.
p = spawn('gulp', ['watch'], {stdio: 'inherit'});
});
Your watch task was probably your default gulp task. Rename it to watch and add a gulp.watch()for watching your gulpfile and run the default task on changes:
gulp.task('watch', ['sass'], function () {
gulp.watch("scss/*.scss", ['sass']);
gulp.watch('gulpfile.js', ['default']);
});
Now, just run gulp and it will automatically reload if you change your gulpfile!
try this code (only win32 platform)
gulp.task('default', ['less', 'scripts', 'watch'], function(){
gulp.watch('./gulpfile.js').once('change' ,function(){
var p;
var childProcess = require('child_process');
if(process.platform === 'win32'){
if(p){
childProcess.exec('taskkill /PID' + p.id + ' /T /F', function(){});
p.kill();
}else{
p = childProcess.spawn(process.argv[0],[process.argv[1]],{stdio: 'inherit'});
}
}
});
});
A good solution for Windows, which also works well with Visual Studio task runner.
/// <binding ProjectOpened='auto-watchdog' />
const spawn = require('child-proc').spawn,
configPaths = ['Gulpconfig.js', 'bundleconfig.js'];
gulp.task('watchdog', function () {
// TODO: add other watches here
gulp.watch(configPaths, function () {
process.exit(0);
});
});
gulp.task('auto-watchdog', function () {
let p = null;
gulp.watch(configPaths, spawnChildren);
spawnChildren();
function spawnChildren() {
const args = ['watchdog', '--color'];
// kill previous spawned process
if (p) {
// You might want to trigger a build as well
args.unshift('build');
setTimeout(function () {
p.kill();
}, 1000);
}
// `spawn` a child `gulp` process linked to the parent `stdio`
p = spawn('gulp', args, { stdio: 'inherit' });
}
});
Main changes compared to other answers:
Uses child-proc because child_process fails on Windows.
The watchdog exits itself on changes of files because in Windows the gulp call is wrapped in a batch script. Killing the batch script wouldn't kill gulp itself causing multiple watches to be spawned over time.
Build on change: Usually a gulpfile change also warrants rebuilding the project.
Install nodemon globally: npm i -g nodemon
And add in your .bashrc (or .bash_profile or .profile) an alias:
alias gulp='nodemon --watch gulpfile.js --watch gulpfile.babel.js --quiet --exitcrash --exec gulp'
This will watch for file gulpfile.js and gulpfile.babel.js changes. (see Google)
P.S. This can be helpful for endless tasks (like watch) but not for single run tasks. I mean it uses watch so it will continue process even after gulp task is done. ;)
Here's a short version that's easy to understand that you can set as a default task so you just need to type "gulp":
gulp.task('watch', function() {
const restartingGulpProcessCmd = 'while true; do gulp watch2 --colors; done;';
const restartingGulpProcess = require('child_process').exec(restartingGulpProcessCmd);
restartingGulpProcess.stdout.pipe(process.stdout);
restartingGulpProcess.stderr.pipe(process.stderr);
});
gulp.task('watch2', function() {
gulp.watch(['config/**.js', 'webpack.config.js', './gulpfile.js'],
() => {
console.log('Config file changed. Quitting so gulp can be restarted.');
process.exit();
});
// Add your other watch and build commands here
}
gulp.task('default', ['watch']);
I spent a whole day trying to make this work on Windows / Gulp 4.0.2, and I (finally) made it...
I used some solutions from people on this page and from one other page. It's all there in the comments...
Any change in any function inside "allTasks" will take effect on gulpfile.js (or other watched files) save...
There are some useless comments and console.logs left, feel free to remove them... ;)
const { gulp, watch, src, dest, series, parallel } = require("gulp");
const spawn = require('child_process').spawn;
// This function contains all that is necessary: start server, watch files...
const allTasks = function (callback) {
console.log('==========');
console.log('========== STARTING THE GULP DEFAULT TASK...');
console.log('========== USE CTRL+C TO STOP THE TASK');
console.log('==========');
startServer();
// other functions (watchers) here
// *** Thanks to Sebazzz ***
// Stop all on gulpfile.js change
watch('gulpfile.js', function (callback) {
callback(); // avoid "task didn't complete" error
process.exit();
});
callback(); // avoid "task didn't complete" error
}
// Restart allTasks
// ********************************************
// CALL GULPDEFAULT WITH THE GULP DEFAULT TASK:
// export.default = gulpDefault
// ********************************************
const gulpDefault = function (callback) {
let p = null;
watch('gulpfile.js', spawnChildren);
// *** Thanks to Sphinxxx: ***
// New behavior in gulp v4: The watcher function (spawnChildren()) is passed a callback argument
// which must be called after spawnChildren() is done, or else the auto-reload task
// never goes back to watching for further changes (i.e.the reload only works once).
spawnChildren(callback);
function spawnChildren(callback) {
/*
// This didn't do anything for me, with or without the delay,
// so I left it there, but commented it out, together with the console.logs...
// kill previous spawned process
if (p) {
// You might want to trigger a build as well
//args.unshift('build');
setTimeout(function () {
console.log('========== p.pid before kill: ' + p.pid); // a random number
console.log('========== p before kill: ' + p); // [object Object]
p.kill();
console.log('========== p.pid after kill: ' + p.pid); // the same random number
console.log('========== p after kill: ' + p); // still [object Object]
}, 1000);
}
*/
// `spawn` a child `gulp` process linked to the parent `stdio`
// ['watch'] is the task that calls the main function (allTasks):
// exports.watch = allTasks;
p = spawn('gulp', ['watch'], { stdio: 'inherit', shell: true });
// *** Thanks to people from: ***
// https://stackoverflow.com/questions/27688804/how-do-i-debug-error-spawn-enoent-on-node-js
// Prevent Error: spawn ENOENT
// by passing "shell: true" to the spawn options
callback(); // callback called - thanks to Sphinxxx
}
}
exports.default = gulpDefault;
exports.watch = allTasks;
Install gulp-restart
npm install gulp-restart
This code will work for you.
var gulp = require('gulp');
var restart = require('gulp-restart');
gulp.task('watch', function() {
gulp.watch(['gulpfile.js'], restart);
})
it will restart gulp where you do changes on the gulpfile.js
How do I execute a Grunt task directly from Node without shelling out to the CLI?
I've got the following "POC" code; however, "stuff" is never logged.
var grunt = require('grunt');
grunt.registerTask('default', 'Log some stuff.', function() {
console.log('stuff');
});
grunt.task.run('default'); // This is probably not the right command
I'm pretty new to Grunt, so I'm probably missing something obvious. I suspect the command I'm using to "run" the task is just queuing it, and doesn't actually start running things. I can't find documentation for manually running things, though.
Update
While this is the answer, Grunt has tons of issues with being run directly from Node. Not the least of which is when the grunt task fails, it calls process.exit and nicely quits your node instance. I cannot recommend trying to get this to work.
Ok, I'll just answer my own question. I was right, the command I had was wrong.
Updated code:
var grunt = require('grunt');
grunt.registerTask('default', 'Log some stuff.', function() {
console.log('stuff');
});
grunt.tasks(['default']);
it take much time and finally, I already made it working for me
var util = require('util')
var exec = require('child_process').exec;
var child = exec("/usr/local/bin/grunt --gruntfile /path/to/Gruntfile.js", function (error, stdout, stderr) {
util.print('stdout: ' + stdout);
util.print('stderr: ' + stderr);
if (error !== null) {
console.log('exec error: ' + error);
}
});
What if you do the following?
grunt.tasks("default");
I've created an Grunt runner in one of my projects that does some parsing and then call the line above. Almostly what you already answered, but with support for a Gruntfile.js.
We're using Jenkins for our builds. So here is how we resolved the issue using bash:
#!/bin/bash
export PATH=$PATH:/usr/local/bin
grunt full-build | tee /dev/stderr | awk '/Aborted/ || /Fatal/{exit 1}'
echo rv: $?
exit $?
The use of /dev/stderr is because we're running within Jenkins and we still want to ouput to show up within the console.
Visualjeff
I'm trying to create a grunt custom task that runs mocha tests but I can't figure out how to have grunt take the colored output from mocha and display it as it does when running the mocha command directly. Ie: grunt strips out the colors or does not pass them through. Here's the grunt task:
var exec = require("child_process").exec;
grunt.registerTask('mocha', 'Run unit (Mocha) tests.', function () {
var done = this.async();
var cmd = "mocha -R Spec tests/mocha/*.js";
exec(cmd, function (error, stdout, stderr) {
if (stdout) {
grunt.verbose.or.write(stdout);
done();
}
});
});
I realize there's a grunt-mocha plugin I could use (and have used) but I'm trying to eliminate dependencies and will also be doing some customization on this task.
Thanks!
This is mostly a duplicate of this question.
You need to add --colors to force Mocha to output ANSI color codes, otherwise it disables colors automatically since it isn't outputting to an actual terminal.
var cmd = "mocha --colors -R Spec tests/mocha/*.js";