node_modules/npm/bin/npm-cli.js

#!/usr/bin/env node
;(function () { // wrapper in case we're in module_context mode

// windows: running "npm blah" in this folder will invoke WSH, not node.
if (typeof WScript !== "undefined") {
  WScript.echo("npm does not work when run\n"
              +"with the Windows Scripting Host\n\n"
              +"'cd' to a different directory,\n"
              +"or type 'npm.cmd <args>',\n"
              +"or type 'node npm <args>'.")
  WScript.quit(1)
  return
}


process.title = "npm"

var log = require("npmlog")
log.pause() // will be unpaused when config is loaded.
log.info("it worked if it ends with", "ok")

var path = require("path")
  , npm = require("../lib/npm.js")
  , npmconf = require("../lib/config/core.js")
  , errorHandler = require("../lib/utils/error-handler.js")

  , configDefs = npmconf.defs
  , shorthands = configDefs.shorthands
  , types = configDefs.types
  , nopt = require("nopt")

// if npm is called as "npmg" or "npm_g", then
// run in global mode.
if (path.basename(process.argv[1]).slice(-1)  === "g") {
  process.argv.splice(1, 1, "npm", "-g")
}

log.verbose("cli", process.argv)

var conf = nopt(types, shorthands)
npm.argv = conf.argv.remain
if (npm.deref(npm.argv[0])) npm.command = npm.argv.shift()
else conf.usage = true


if (conf.version) {
  console.log(npm.version)
  return
}

if (conf.versions) {
  npm.command = "version"
  conf.usage = false
  npm.argv = []
}

log.info("using", "npm@%s", npm.version)
log.info("using", "node@%s", process.version)

process.on("uncaughtException", errorHandler)

if (conf.usage && npm.command !== "help") {
  npm.argv.unshift(npm.command)
  npm.command = "help"
}

// now actually fire up npm and run the command.
// this is how to use npm programmatically:
conf._exit = true
npm.load(conf, function (er) {
  if (er) return errorHandler(er)
  npm.commands[npm.command](npm.argv, errorHandler)
})

})()