nshell
A work-in-progress scriptable shell written with node (replacing bash, ksh, etc).
Installation
$ npm install -g nshell
For now clone and:
$ npm install
$ ./bin/shell
About
Just started this as a quick proof of concept, but it's kinda fun! Keep in mind this is not an attempt to become a POSIX shell.
Features
Small set of features so far:
- PS1
- pipelining
- scriptability!
- aliases
- sources
~/.profile.js
- saves history to
~/.nshell-history
- brace expansion
- filename auto-completion
- some built-ins
- some magic variables
Built-ins
Currently the following built-ins are available:
.
-- source a javascript filecd
-- change directorywhich
-- search PATH for an executableexit
-- exit nshellhistory
-- view history
Variables
Currently the following magic vars are available:
$?
the exit status of the previous command!!
the string value of the previous command
Events
Hook into events with shell.on(event, callback)
:
cd
(dir) changing directoriesexec
(line) is about to be executedalias
(name, cmd) when an alias is definedsource
(file, mod) when a module is sourcedcommand
(e) when a command line is inputted, but not yet executed
~/.profile.js
By default nshell(1)
currently sources ~/.profile.js
,
this is where you can put config much like other shells.
PS1
Change your PS1 prompt by exporting a string:
exports.PS1 = "tj> ";
Or create something more dynamic and fancy by exporting a function:
var colors = [31, 32, 33, 34, 35, 36];
exports.PS1 = function(){
var color = colors[Math.random() * colors.length | 0];
return '\033[' + color + 'm>\033[m ';
};
Brace expansion
Brace expansion works as you'd expect:
> touch foobar
> touch foobaz
> rm foo{bar,baz}
Sourcing
You may source files much like you do with require()
in node,
support you have "test.js", you may load it with either of
the following:
βΈ . test.js
βΈ . test
Aliases
shell.alias('GET', 'burl GET');
shell.alias('HEAD', 'burl -I');
shell.alias('POST', 'burl POST');
shell.alias('PUT', 'burl PUT');
shell.alias('PATCH', 'burl PATCH');
shell.alias('DELETE', 'burl DELETE');
shell.alias('DEL', 'burl DELETE');
shell.alias('OPTIONS', 'burl OPTIONS');
Debugging
$ DEBUG=nshell ./bin/shell
βΈ cat Readme.md
nshell cmd [{"name":"cat","argv":["Readme.md"]}] +1.1m
nshell env {} +0ms
nshell which cat +0ms
nshell found /bin/cat +2ms
nshell spawn /bin/cat ["Readme.md"] +0ms
nshell exit 0 +5ms
nshell prompt +0ms
Examples
Some cool examples showing off the power of scripting your shell!
Auto-cd
By default nshell(1)
does not auto-chdir when
the given line is a directory, however you can
easily script this in:
var fs = require('fs')
, exists = fs.existsSync
, stat = fs.statSync;
// auto-cd
shell.on('command', function(e){
var path = e.line.trim();
if (exists(path) && stat(path).isDirectory) {
e.preventDefault();
shell.exec('cd "' + path + '"');
}
});
Usage:
βΈ pwd
/Users/tj/projects/nshell
βΈ node_modules/commander
βΈ pwd
/Users/tj/projects/nshell/node_modules/commander
βΈ ../..
βΈ pwd
/Users/tj/projects/nshell
Auto-edit
By default nshell(1)
will simply give you
a "command not found" error if you try to
type a filename, however you can script
in the ability to edit that file depending
on its mime type:
// $ npm install mime
var path = require('path');
var mime = require('mime');
// auto-editor (silly implementation)
shell.on('command', function(e){
var line = e.line.trim();
var type = mime.lookup(line);
switch (type) {
case 'text/plain':
case 'text/css':
case 'application/javascript':
e.preventDefault();
shell.exec('mate "' + line + '"');
break;
}
});
Command replay
To replay the previous command on a blank line
you can also listen on the "command" event and
use the shell.lastCommand
property, which is
populated by the last successfully executed
command line.
shell.on('command', function(e){
if ('' == e.line.trim()) {
e.preventDefault();
shell.exec(shell.lastCommand);
}
});
JavaScript expansion
Modifications to e.line
are accepted by nshell,
this means you can progressively layer on plugins,
in this case a naive implementation of "js expansion":
shell.on('command', function(e){
e.line = expansion(e.line);
});
function expansion(line) {
return line.replace(/`(.*?)`/, function(_, js){
return eval('(' + js + ')');
});
}
Usage:
βΈ echo `Math.pow(2, 32)`
βΈ 4294967296
βΈ cat `"Make" + "file"`
test:
@./node_modules/.bin/mocha \
--require should \
--reporter spec
...
License
(The MIT License)
Copyright (c) 2012 TJ Holowaychuk <[email protected]>
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the 'Software'), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.