Execute bash command in Node.js and get exit code
Those 2 commands are running in separate shells.
To get the code, you should be able to check err.code
in your callback.
If that doesn't work, you need to add an exit
event handler
e.g.
dir = exec("ls -la", function(err, stdout, stderr) {
if (err) {
// should have err.code here?
}
console.log(stdout);
});
dir.on('exit', function (code) {
// exit code is code
});
From the docs:
If a
callback
function is provided, it is called with the arguments(error, stdout, stderr)
. On success,error
will benull
. On error,error
will be an instance of Error. Theerror.code
property will be the exit code of the child process whileerror.signal
will be set to the signal that terminated the process. Any exit code other than 0 is considered to be an error.
So:
exec('...', function(error, stdout, stderr) {
if (error) {
console.log(error.code);
}
});
Should work.
child_process.spawnSync()
This function exposes the nicest sync interface: https://nodejs.org/api/child_process.html#child_process_child_process_spawnsync_command_args_options
Example:
#!/usr/bin/env node
const child_process = require('child_process');
let out;
out = child_process.spawnSync('true');
console.log('status: ' + out.status);
console.log('stdout: ' + out.stdout.toString('utf8'));
console.log('stderr: ' + out.stderr.toString('utf8'));
console.log();
out = child_process.spawnSync('false');
console.log('status: ' + out.status);
console.log('stdout: ' + out.stdout.toString('utf8'));
console.log('stderr: ' + out.stderr.toString('utf8'));
console.log();
out = child_process.spawnSync('echo', ['abc']);
console.log('status: ' + out.status);
console.log('stdout: ' + out.stdout.toString('utf8'));
console.log('stderr: ' + out.stderr.toString('utf8'));
console.log();
Output:
status: 0
stdout:
stderr:
status: 1
stdout:
stderr:
status: 0
stdout: abc
stderr:
Tested in Node.js v10.15.1, Ubuntu 19.10.