Takes a filename as an argument. It will then treat each line from this file as a command and spawn a process with it. Finally it will multiplex the output of each of those processes, prefixing each line with the PID of that process.

npm install -g multiplexer

echo "\
while [ 1 ] ; do echo beep ; sleep 1 ; done
while [ 1 ] ; do echo boop ; sleep 1 ; done
while [ 1 ] ; do echo baap ; sleep 1 ; done" > example-commands

multiplexer example-commands

Output:

25242 beep
25244 boop
25246 baap
25242 beep
25244 boop
25246 baap
25242 beep
25244 boop
25246 baap

npm install multiplexer

const multiplexer = require('multiplexer')

multiplexer([
  'while [ 1 ] ; do echo beep ; sleep 1 ; done',
  'while [ 1 ] ; do echo beep ; sleep 1 ; done',
  'while [ 1 ] ; do echo beep ; sleep 1 ; done'
])

Instead of a string, each command can be an object with the following fields:

• cwd ... Set working directory
• env ... Set of environment key-value pairs
• uid ... Run as User ID
• gid ... Run as Group ID
• detached ... Detach from parent process
• alias ... Custom log prefix (default: process id)
• waitFor ... Wait for process to print given string to stdout before spawning next process