Example use of spawnSync

spawnSync_example.js

'use strict'

// https://nodejs.org/api/child_process.html#child_process_child_process_spawnsync_command_args_options
const spawn = require('child_process').spawnSync

// object returned when process has completely exited
const child = spawn('which', ['node'] )

// view status
console.log( child.status )

// view output (stdout & stderr combined)
// must convert buffer to string
console.log (child.output.toString('utf8') )

// e.g. function that uses spawnSync
// which: displays user path to specified binary
// @param command
// @return object
function which(cmd){ 
  return spawn('which', [cmd])
}

console.log( which('npm').stdout.toString('utf8') )

// piping
console.log( 
  "NODE PROCESSES: " + 
  spawn('grep', ['node'], { input: spawn('ps', ['aux'] ).stdout })
    .stdout.toString('utf8')
)


process.on('exit', function() { console.log('bye') } )