completion - install instruction and simple line parsing/callback api

Run `<pkgname> completion` for install instruction.
Run `<pkgname> completion >> datauri completion >> ~/.bashrc` (or ~/.zshrc)

Simply log in the callback to show completion output.

bin/pkgrc

@@ -1,7 +1,31 @@
 #!/usr/bin/env node
+var completion = require('../lib/completion');
 
-console.log('Executing pkgrc bin file');
+// this file is mainly just an example of usage
 
-var args = process.argv.slice(2);
-console.log('Args are: ', args);
+// pass the module name, will change to module
+// reference + dir walk to find a package.json
+completion.complete('pkgrc', function(err, o) {
+  if(err || !o) return;
 
+  // options:
+  // - line: the full line from compgen
+  // - partial: the partial line, part of the line where the cursor is
+  // - words: the word counter, a number mapping the number of words from compgen
+  // - point: cursor offset
+
+  //
+  // Setting completion output is simply a matter of writing to the console
+  //
+
+  console.log(o.line);
+  console.log(o.partial);
+  console.log(o.words);
+  console.log(o.point);
+  console.log(o.last);
+  console.log(o.lastPartial);
+
+  if(o.partial === 'hello') {
+    console.log('World');
+  }
+});

lib/completion.js

@@ -0,0 +1,61 @@
+
+var fs = require('fs'),
+  path = require('path'),
+  args = process.argv.slice(2),
+  complete = args[0] === 'completion',
+  words = process.env.COMP_CWORD,
+  point = process.env.COMP_POINT,
+  line = process.env.COMP_LINE;
+
+// check bin/pkgrc for usage example.
+//
+// Run `<pkgname> completion` for install instruction.
+// Run `<pkgname> completion >> datauri completion >> ~/.bashrc` (or ~/.zshrc)
+//
+// Simply log in the callback to show completion output.
+
+exports.complete = function(name, cb) {
+
+  cb = cb || function(){};
+
+  // if not a complete command, return here.
+  if(!complete) return cb();
+
+  // if the COMP_* are not in the env, then dump the install script.
+  if(!words || !point || !line) return script(name, cb);
+
+  var partial = line.substr(0, point),
+  last = line.split(' ').slice(-1).join(''),
+  lastPartial = partial.split(' ').slice(-1).join('');
+
+  cb(null, {
+    line: line,
+    words: words,
+    point: point,
+    partial: partial,
+    last: last,
+    lastPartial: lastPartial
+  });
+};
+
+// simple helper function to know if the script is run
+// in the context of a completion command. Also mapping the
+// special `<pkgname> completion` cmd.
+exports.isComplete = function() {
+  return complete || (words && point && line);
+};
+
+// output the completion.sh script to the console for install instructions.
+// This is actually a 'template' where the package name is used to setup
+// the completion on the right command, and properly name the bash/zsh functions.
+function script (name, cb) {
+  var p = path.resolve(__dirname, 'completion/completion.sh');
+
+  fs.readFile(p, 'utf8', function (er, d) {
+    if (er) return cb(er);
+    d = d.replace(/\{pkgname\}/g, name);
+    console.log(d);
+    cb();
+  });
+}
+

lib/completion/completion.sh

@@ -1,32 +1,31 @@
-#!/bin/bash
-###-begin-pkgrc-completion-###
+
+###-begin-{pkgname}-completion-###
 ### credits to npm, this file is coming directly from isaacs/npm repo
 #
 # Just testing for now. (trying to learn this cool stuff)
 #
 # npm command completion script
 #
-# Installation: pkgrc completion >> ~/.bashrc  (or ~/.zshrc)
-# Or, maybe: pkgrc completion > /usr/local/etc/bash_completion.d/npm
+# Installation: {pkgname} completion >> ~/.bashrc  (or ~/.zshrc)
 #
 
 COMP_WORDBREAKS=${COMP_WORDBREAKS/=/}
 COMP_WORDBREAKS=${COMP_WORDBREAKS/@/}
 export COMP_WORDBREAKS
 
 if complete &>/dev/null; then
-  _npm_completion () {
+  _{pkgname}_completion () {
     local si="$IFS"
     IFS=$'\n' COMPREPLY=($(COMP_CWORD="$COMP_CWORD" \
                            COMP_LINE="$COMP_LINE" \
                            COMP_POINT="$COMP_POINT" \
-                           pkgrc completion -- "${COMP_WORDS[@]}" \
+                           {pkgname} completion -- "${COMP_WORDS[@]}" \
                            2>/dev/null)) || return $?
     IFS="$si"
   }
-  complete -F _npm_completion pkgrc
+  complete -F _{pkgname}_completion {pkgname}
 elif compctl &>/dev/null; then
-  _npm_completion () {
+  _{pkgname}_completion () {
     local cword line point words si
     read -Ac words
     read -cn cword
@@ -37,10 +36,11 @@ elif compctl &>/dev/null; then
     IFS=$'\n' reply=($(COMP_CWORD="$cword" \
                        COMP_LINE="$line" \
                        COMP_POINT="$point" \
-                       pkgrc completion -- "${words[@]}" \
+                       {pkgname} completion -- "${words[@]}" \
                        2>/dev/null)) || return $?
     IFS="$si"
   }
-  compctl -K _npm_completion pkgrc
+  compctl -K _{pkgname}_completion {pkgname}
 fi
-###-end-npm-completion-###
+###-end-{pkgname}-completion-###
+

package.json

@@ -7,6 +7,7 @@
     "type": "git",
     "url": "git://github.com/mklabs/pkgrc.git"
   },
+  "main": "./lib/completion",
   "bin": "./bin/pkgrc",
   "engines": {
     "node": "> 0.4"