I wrote the following web server in node.js using express and hbs that can run shell files, but I keep getting the following error when I type this url into a web browser
linux username here is replaced with my linux username
http://127.0.0.1:3000/run?file="/home/linux username here/nasServer/GameServers/minecraft/1.16.2 server/run.sh"
stderr: bash: <path to .sh file here>: No such file or directory.
child process exited with code 127.
Contents of nodejs file:
const express = require('express')
const hbs = require('hbs')
const app = express()
const port = 3000
// Set up handlebars engine
app.set('view engine', 'hbs')
app.get('/run', (req, res) => {
const { spawn } = require('child_process');
let callback = ""
ls = spawn("bash", [req.query.file])
ls.stdout.on('data', function (data) {
console.log('stdout: ' + data.toString());
});
ls.stderr.on('data', function (data) {
console.log('stderr: ' + data.toString());
});
ls.on('close', function (code) {
console.log('child process exited with code ' + code.toString());
});
res.send({
out: callback
})
})
app.listen(port, () => {
console.log(`App listening on port ${port}`)
})
This is the contents of run.sh:
#!/bin/bash
java -Xmx5G -jar /home/linux username here/nasServer/GameServers/minecraft/1.16.2\ server/spigot-1.16.2.jar nogui
Hello, I don't know why I decided to try to fix this since I know just a little bit about coding (only scripting actually lol) and nothing about nodeJs but I got fun testing your app with the help of my friend google !
First of all, since i dont have your minecraft files (jar etc.), I just writed a little script "test.sh", that will just echo your command:
❯ cat test.sh
#!/bin/bash
echo "java -Xmx5G -jar /home/linux username here/nasServer/GameServers/minecraft/1.16.2\ server/spigot-1.16.2.jar nogui"
second of all after like 2hours of training, modifying, testing by adding/deleting stuff into your app to understand how it works, I finally came back to your original app when i find that it works with this:
http://localhost:3000/run?file=test.sh
here is the browser output (as expected):
{"out":""}
here is the console output:
❯ node 71963151.js
App listening on port 3000
stdout: java -Xmx5G -jar /home/linux username here/nasServer/GameServers/minecraft/1.16.2\ server/spigot-1.16.2.jar nogui
child process exited with code 0
The fact is that when we remove the double quotes from the query it works fine, but when I add back the double quotes like you are trying to do:
http://localhost:3000/run?file="test.sh"
here is the browser output (as expected):
{"out":""}
but here is the consol output:
❯ node 71963151.js
App listening on port 3000
stderr: bash: "test.sh": No such file or directory
child process exited with code 127
So, to conclude, instead of trying to run this on your browser:
http://127.0.0.1:3000/run?file="/home/<linux username here>/nasServer/GameServers/minecraft/<1.16.2 server>/run.sh"
try this:
http://127.0.0.1:3000/run?file=/home/<linux username here>/nasServer/GameServers/minecraft/<1.16.2 server>/run.sh
A lot of documentation helped me out to understand the way nodejs works, I loved doing this :p thank you, You made me want to code!
bguess.
I fixed the problem by replacing all the windows line endings with Unix line endings, then bash found the .sh file.
Related
I ran my first server and seems fine except that it won't stop running. I cannot even type anything else in the command line. I will appreciate any help
Here is the code I ran
const http = require('http');
const hostname = '127.0.0.1';
const port = 3000;
const server = http.createServer((req, res) =>
{
res.statusCode = 200;
res.setHeader('Content-Type', 'text/plain');
res.end('In the name of Allah, the Most Gracious, the Most Merciful.');
});
server.listen(port, hostname, () =>
{
console.log(`Server running at http://${hostname}:${port}/`);
});
But the problem is not the code, rather how to get back to this command line
$papus#QuantumOne MINGW64 /c/Projects/firstServer so that I can start retyping again on the command line without closing everything down and restart the whole process.
right now it gets stuck on Server running at http://127.0.0.1:3000 forever
Because it is a server and it is not supposed to stop after a time.
You can shut down by pressing ctrl + c
Or you can program a certain route that will kill it programatically (i did not say it should be done)
If you want to continue using the same terminal you can run the server in background (on unix systems it is done by adding & at the end of the start command)
You can also look at process manager for nodejs server like pm2
I'm trying to do a little application with node.js that would run on mac and execute some commands.
I've successfully used spawn to run command lines such as xcodebuild, but xcrun doesn't seems to work when I try to open the iOS Simulator.
I can open on terminal by typing:
xcrun instruments -w 'iPhone 5s (9.2)' -t <template>
But if I use node and try to use spawn like this:
var args = ['instruments', '-w', `iPhone 5s (9.2)`, '-t', 'noTemp'];
var xcrun = spawn('xcrun', args);
So it got me thinking that maybe it had some limitation opening apps? I tried to run:
var args = ['/Applications/Spotify.app'];
var xcrun = spawn('open', args);
And nothing happens. I couldn't find anything related to that. My question is: is there anyway to open apps using node.js spawn? If there is, does someone know what's the problem with my code?
Here's the full code if needed:
var args = ['instruments', '-w', `${fullDevice}`, '-t', 'noTemp'];
var xcrun = spawn('xcrun', args);
xcrun.stdout.on('data', (data)=>{
console.log(data.toString('utf8'));
})
xcrun.on('close', (code) => {
socket.emit({
time: commands.getCurrentTime(),
type: 'success',
log: 'Device booted...'
});
callback();
if (code !== 0) {
console.log(`open process exited with code ${code}`);
}
});
OBS: if I run this piece of code the application doesn't terminate, the program doesn't continue and nothing happens.
EDIT: Changed:
xcrun.on('data', (data)=>{
To:
xcrun.stdout.on('data', (data)=>{
Spawned processes have two separate streams for stdout and stderr, so you will need to listen for data on those objects and not the spawned process object itself:
xcrun.stdout.on('data', function(data) {
console.log('stdout: ' + data.toString());
});
xcrun.stderr.on('data', function(data) {
console.log('stderr: ' + data.toString());
});
The problem was one line above. Not sure why, but there's a socket.emit call that is wrong and actually hold the program's execution.
When i run this pidof command by hand, it works. Then put into my server.js.
// send signal to start the install script
var spw = cp.spawn('/sbin/pidof', ['-x', 'wait4signal.py', '|', 'xargs', 'kill', '-USR1']);
spw.stderr.on('data', function(data) {
res.write('----- Install Error !!! -----\n');
res.write(data.toString());
console.log(data.toString());
});
spw.stdout.on('data', function(data) {
res.write('----- Install Data -----\n');
res.write(data.toString());
console.log(data.toString());
});
spw.on('close', function(data) {
res.end('----- Install Finished, please to to status page !!! -----\n');
console.log('88');
});
In the web i only see "----- Install Finished, please to to status page !!!". My install script seems never get this USR1 signal. Anything wrong please ?
The problem is that you have two separate commands. You are piping the output of your /sbin/pidof command to the input stream of your xargs command. If you are using spawn (rather than exec, which a string exactly as you would write on the command line), you need to spawn one process per command.
Spawn your processes like this:
const pidof = spawn('/sbin/pidof', ['-x', 'wait4signal.py']);
const xargs = spawn('xargs', ['kill', '-USR1']);
Now pipe the output of the first process to the input of the second, like so:
pidof.stdout.pipe(xargs.stdin);
Now you can listen to events on your xargs process, like so:
xargs.stdout.on('data', data => {
console.log(data.toString());
});
I cannot get any output in the following code:
var spawn = require('child_process').spawn,
script = 'ftp',
child = spawn(script);
child.stdout.on('data', function (data) {
console.log('stdout: ' + data);
});
child.stderr.on('data', function (data) {
console.log('stderr: ' + data);
});
child.on('close', function (code) {
console.log('child process exited with code ' + code);
});
It works for normal scripts such as 'ls', 'pwd' etc. But not for interactive programs such as 'ftp', 'telnet'. Any suggestions?
Edit:
Take another script for example:
#!/usr/bin/env python
name = raw_input("your name>")
print name
When spawn this script, I wish to fetch the prompt "your name>" with the data event, so that I can latter input something into stdin.
The problem is that I got nothing in the data event, and it seemed that none of these events are triggered.
ls, cat is controllable via input output and error stream.
ftp, telnet is controllable indirectly via tty.
The protocol is also base on input/output stream but it is more complicated. You can use available package to handle that protocol.
https://github.com/chjj/pty.js
var pty = require('pty.js');
var term = pty.spawn('ftp', [], options);
term.on('data', function(data) {
console.log(data);
});
term.write(ftpCmd + '\r');
The author of pty have some interesting examples, he forward pty to web via web socket, including terminal games:
https://github.com/chjj/tty.js
In interactive mode there is a command interpreter that reads user input from stdin, then accodingly prints output. So you have to write to stdin to do something. For example add following lines to your code with telnet command:
child.stdin.write('?\n');
child.stdin.write('quit\n');
Output:
stdout: Commands may be abbreviated. Commands are:
! cr mdir proxy send
$ delete mget sendport site
account debug mkdir put size
append dir mls pwd status
ascii disconnect mode quit struct
bell form modtime quote system
binary get mput recv sunique
bye glob newer reget tenex
case hash nmap rstatus trace
ccc help nlist rhelp type
cd idle ntrans rename user
cdup image open reset umask
chmod lcd passive restart verbose
clear ls private rmdir ?
close macdef prompt runique
cprotect mdelete protect safe
child process exited with code 0
I have a child process that I am using as follows in node.js. Instead of redirecting the output to the console I would like to put the output in a log file located somewhere on the machine this is running on (and should work for both windows and mac).
The code below is what I am using and I would like to output the files into a log file. What changes needed to do that here? Thanks!
My Code:
var spawn = require('child_process').spawn,
ls = spawn('ls', ['-lh', '/usr']);
ls.stdout.on('data', function (data) {
console.log('stdout: ' + data);
});
ls.stderr.on('data', function (data) {
console.log('stderr: ' + data);
});
ls.on('close', function (code) {
console.log('child process exited with code ' + code);
});
Here's an example of logging to file using streams.
var logStream = fs.createWriteStream('./logFile.log', {flags: 'a'});
var spawn = require('child_process').spawn,
ls = spawn('ls', ['-lh', '/usr']);
ls.stdout.pipe(logStream);
ls.stderr.pipe(logStream);
ls.on('close', function (code) {
console.log('child process exited with code ' + code);
});
There are two ways you can achieve this, one is using
let logConsoleStream = fs.createWriteStream('./logConsoleFile.log', {flags: 'a'});
let logErrorStream = fs.createWriteStream('./logErrorFile.log', {flags: 'a'});
and redirect all logs or errors using this
ls.stdout.pipe(logConsoleStream ); // redirect stdout/logs only
ls.stderr.pipe(logErrorStream ); // redirect error logs only
by separating log files you will have separate files for Error logs and console logs
this is exactly same as generalhenry shared above
And Second Way for Achieving this with the help of Command Line
when you execute node app from the command line
node app/src/index.js
you can specify here where you want to redirect logs and Errors from this application
there are three stream redirection commands using the command line
`>` It will redirect your only stdout or logs to the specified path
`2>` It will redirect your errors logs to the specified path
`2>&1 ` It will redirect all your stdout and stderr to a single file
example: how you will use these commands
node app/src/index.js > ./logsOnly.txt
node app/src/index.js 2> ./ErrorsOnly.txt
node app/src/index.js 2>&1 ./consoleLogsAndErrors.txt
I hope someone coming later finds this helpful
if there is I done wrong way please do let me know it will help me and others
Thanks
If you run your JS script with forever then you have the option to define a log file as parameter which will handle all your console.log messages. Not to mention the benefit of keeping your nodejs app live permanently.
Alternatively try this:
sudo forever start myapp.js 2>&1 /home/someuser/myapp/myapp.log
use forever with below options
forever start -o out.log -e err.log server.js
The best answer was in the comments and is mentioned in a previous question here: stackoverflow.com/questions/2496710/nodejs-write-to-file
It is as follows:
var fs = require('fs');
fs.writeFile("/tmp/test", "Hey there!", function(err) {
if(err) {
console.log(err);
} else {
console.log("The file was saved!");
}
});