brsolab-process

brsolab-process

Wrapper for Nodejs Child process library Uses the ES6 to make it simple the use of subprocess in nodeJS

This library contains 3 functions: spawn, exec, and escape spawn is used to create processes. exec is used to execute commandes via the system interpreter (SH, BATCH, MS-DOS, ...) escape is used to escape arguments to exec commande

Those two functions use the some options as the original ones of nodejs. See the doc page at: https://nodejs.org/api/child_process.html

spawn

/**
 * spawn process
 * spaw(cmd, [args, [options, [processInitCallBack]]])
 * spaw(cmd, [args, [processInitCallBack]])
 * @param  {string} command The command to run
 * @param  {Array} args    List of string arguments
 * @param  {Object} options
 *         timeout{number}		: process execution timeout in ms 
 *         cwd	{String}		: Current working directory of the child process
 *         env	{Object}		: Environment key-value pairs
 *         argv0{String}		: Explicitly set the value of argv[0] sent to the child process. This will be set to command if not specified.
 *         stdio{Array | String}: Child's stdio configuration
 *         detached{boolean}	: Prepare child to run independently of its parent process.
 *         uid	{number}		: Sets the user identity of the process
 *         gid	{number}		: Sets the group identity of the process
 *         shell{boolean|string}: If true, runs command inside of a shell. Uses '/bin/sh' on UNIX, and process.env.ComSpec on Windows. A different shell can be specified as a string.
 * @return {Promise}
 */

const {spawn} = require('brsolab-process');
var list	= await spawn('ls', ['-l', '/home'], {timeout: 500});

exec

/**
 * exec process
 * exec(cmd, [options, [processInitCallBack]])
 * spaw(cmd, [processInitCallBack])
 * @param  {string} command The command to run
 * @param  {Array} args    List of string arguments
 * @param  {Object} options
 *         timeout{number}		: process execution timeout in ms 
 *         cwd	{String}		: Current working directory of the child process
 *         env	{Object}		: Environment key-value pairs
 *         argv0{String}		: Explicitly set the value of argv[0] sent to the child process. This will be set to command if not specified.
 *         stdio{Array | String}: Child's stdio configuration
 *         detached{boolean}	: Prepare child to run independently of its parent process.
 *         uid	{number}		: Sets the user identity of the process
 *         gid	{number}		: Sets the group identity of the process
 *         shell{boolean|string}: If true, runs command inside of a shell. Uses '/bin/sh' on UNIX, and process.env.ComSpec on Windows. A different shell can be specified as a string.
 * @return {Promise}
 */

const {exec, escape} = require('brsolab-process');
var list	= await exec('ls ' + escape(['-l', '/home']), {timeout: 500});
await exec('ls ' + escape(['-l', '/home']) + ' > list.txt', {timeout: 500});

examples

const { spawn, exec } = require('brsolab-process');
const fs  = require('fs');

exec('ls .').then( result => console.log(result) ).catch( error => console.error(error) );

// it's better to use "async" & "await"
(async function(){
  result  = await spawn('command', [args]);
  console.log(result);
  
  // pipe the output to a file
  await spawn('commande', [args], {stdio : ['pipe', fs.openSync('file.txt'), 'pipe']});
  
  // send messages to process
  var result = await spawn('cmd', [args], {options}, prcess => {
    // operations on prcess
    prcess.send({ foo: 'bar', baz: NaN });
  });
})();