argv-or-stdin

argv-or-stdin

use the 1st argument, or, if none is present, standard input

Sometimes you want to write a tool that takes a filename as its argument. However, if there is no argument provided, it'd be great to also accept it on standard input.

Usage

Let's write a simple version of the program cat:

cat.js

var arg = require('argv-or-stdin')
var fs = require('fs')

arg(function (err, filename) {
  fs.createReadStream(filename)
    .pipe(process.stdout)
})

And test it:

$ cat > test
hello warld
^D

$ node cat.js test
hello warld

$ echo 'test' | node cat.js
hello warld

API

var arg = require('argv-or-stdin')

arg(cb)

A function that will check process.argv[2] and, if it does not exist, accumulate all of process.stdin into a string and return that.

cb is a callback function of the form function (err, name) {}.

Install

With npm installed, run

$ npm install argv-or-stdin

See Also

• noffle/common-readme

License

ISC