gistfile1.txt

#!/usr/bin/env coffee

# A useful little script to execute a shell command when another
# command exits successfully. Kind of like using && except the 
# first command will keep executing until it returns successfully.
#
# My use case was starting up a local rails server. It takes ~15
# seconds and I have no indication of when it's ready besides manually
# polling lsof. So with this script I just do the following to start
# profiling my app when it's online.
#
# $ when lsof -i :3000 && ab -c10 -n100 http://127.0.0.1:3000/

spawn = require('child_process').spawn
sys   = require 'sys'
prog  = process.argv.slice(2, 3)[0]
args  = process.argv.slice 3, process.argv.length

testProgram = (prog, args) ->
  test = spawn prog, args

  test.on 'exit', (code) ->
    if code == 0
      sys.print "\n"
      process.exit 0
    else
      sys.print '.'
      callback = -> testProgram prog, args
      setTimeout callback, 1000

testProgram prog, args