Executing shell script from code

Question

I am trying to execute a shell script from nodejs code

//test.sh
wget http://nodejs.org/dist/v0.10.26/node-v0.10.26-linux-x64.tar.gz
tar -zxvf node-v0.10.26-linux-x64.tar.gz
mv node-v0.10.26-linux-x64 node-v0.10.26
sudo cp -r node-v0.10.26 /usr/local/src
//app.js
var exec = require('child_process').exec;
 var execProcess = require("./exec_process.js");
execProcess.result("sh test.sh", function(err, response){
 if(!err){
 console.log(response);
 }else {
 console.log(err);
 }
});
//exec_process.js
 var exec = require('child_process').exec;
var result = function(command, cb){
 var child = exec(command, function(err, stdout, stderr){
 if(err != null){
 return cb(new Error(err), null);
 }else if(typeof(stderr) != "string"){
 return cb(new Error(stderr), null);
 }else{
 return cb(null, stdout);
 }
 });
}
exports.result = result;

After executing app.js, I am not able to see anything in response. What I am doing wrong here?

• mugabits: is the exec variable inside your app.js your child_process instance? I use the spawn method. If you wanted to see some response then you should send something out to the console.
• mugabits: Have you tried instead of putting sh test.sh to just put its path relative to the working directory. Also check your executing permissions.
• user4324324: sh test.sh is working for me

Answer 1

Try this

// app.js
require('child_process').spawn('sh', ['test.sh'], {stdio: 'inherit'});

• Murali N: sweet and simple

Answer 2

The code works for me perfectly, without any changes. When you say you are not able to see any response, does the process hang? what is the final outcome? I doubt the sudo command in the script is causing some issues. Can you eliminate that and change? I don't have sudo access, so it failed on prompt.

 bash-4.1$ node app.js
[sudo] password for gireesh:
[sudo] password for gireesh:
[sudo] password for gireesh:
[Error: Error: Command failed: /bin/sh -c sh test.sh
--2016年04月27日 08:28:01-- http://nodejs.org/dist/v0.10.26/node-v0.10.26-linux-x64.tar.gz
Resolving nodejs.org... 104.20.22.46, 104.20.23.46, 2400:cb00:2048:1::6814:172e, ...
Connecting to nodejs.org|104.20.22.46|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 5314716 (5.1M) [application/octet-stream]
Saving to: ânode-v0.10.26-linux-x64.tar.gz.2â

Some diagnostic steps:

• Print the child object, after the excec call. This will print the process information pertinent to the child. This will make sure the child is started.
• Install a child terminator callback, and print a debug information in it. This will make sure the child is ended.
• If still problem persists, install child stream hooks. This will make sure the instantaneous prints in the streams are output immediately, rather than at the end.

Modified exec_process.js

var exec = require('child_process').exec;
var result = function(command, cb){
 var child = exec(command, function(err, stdout, stderr){
 if(err != null){
 return cb(new Error(err), null);
 }else if(typeof(stderr) != "string"){
 return cb(new Error(stderr), null);
 }else{
 return cb(null, stdout);
 }
 });
 console.log(child);
 child.on('close', function(code) {
 console.log('child ended with: ' + code);
 });
 child.on('error', function(err) {
 console.log('child errd with: ' + err);
 });
 child.stdout.on('data', function(d) {
 console.log('child stdout: ' + d);
 });
}
exports.result = result;

Hope this helps.