I need to execute a bash script in node.js. Basically, the script will create user account on the system. I came across this example which gives me an idea how to go about it. However, the script itself needs arguments like the username, the password and the real name of the user. I still can't figure out how to pass those arguments to the script doing something like this:
var commands = data.toString().split('\n').join(' && ');
Does anyone have an idea how I can pass those arguments and execute the bash script within node.js over an ssh connection. thanks
At the very least, a script that's run without any arguments will still contain two items in the array, the node executable and the script file that is being run.
The arguments object is an array-like object. It has a length property that corresponds to the number of arguments passed into the function. You can access these values by indexing into the array, e.g. arguments[0] is the first argument.
Node. js can run shell commands by using the standard child_process module. If we use the exec() function, our command will run and its output will be available to us in a callback. If we use the spawn() module, its output will be available via event listeners.
See the documentation here. It is very specific on how to pass command line arguments. Note that you can use exec
or spawn
. spawn
has a specific argument for command line arguments, while with exec
you would just pass the arguments as part of the command string to execute.
Directly from the documentation, with explanation comments inline
var util = require('util'), spawn = require('child_process').spawn, ls = spawn('ls', ['-lh', '/usr']); // the second arg is the command // options ls.stdout.on('data', function (data) { // register one or more handlers console.log('stdout: ' + data); }); ls.stderr.on('data', function (data) { console.log('stderr: ' + data); }); ls.on('exit', function (code) { console.log('child process exited with code ' + code); });
Whereas with exec
var util = require('util'), exec = require('child_process').exec, child; child = exec('cat *.js bad_file | wc -l', // command line argument directly in string function (error, stdout, stderr) { // one easy function to capture data/errors console.log('stdout: ' + stdout); console.log('stderr: ' + stderr); if (error !== null) { console.log('exec error: ' + error); } });
Finally, note that exec buffers the output. If you want to stream output back to a client, you should use spawn
.
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