npm install nshellA work-in-progress scriptable shell written with node (replacing bash, ksh, etc).
$ npm install -g nshell
For now clone and:
$ npm install
$ ./bin/shell
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.
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
Currently the following built-ins are available:
- . -- source a javascript file
- cd -- change directory
- which -- search __PATH__ for an executable
- exit -- exit nshell
- history -- view history
Currently the following magic vars are available:
- $? the exit status of the previous command
- !! the string value of the previous command
Hook into events with shell.on(event, callback):
- cd (dir) changing directories
- exec (line) is about to be executed
- alias (name, cmd) when an alias is defined
- source (file, mod) when a module is sourced
- command (e) when a command line is inputted, but not yet executed
By default nshell(1) currently sources ~/.profile.js,
this is where you can put config much like other shells.
Change your __PS1__ prompt by exporting a string:
``js`
exports.PS1 = "tj> ";
Or create something more dynamic and fancy
by exporting a function:
`js
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 works as you'd expect:
`
> touch foobar
> touch foobaz
> rm foo{bar,baz}
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:
`
▸ . test.js
▸ . test
`js`
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');
`js`
$ DEBUG=nshell ./bin/shell
▸ 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
Some cool examples showing off the power
of scripting your shell!
By default nshell(1) does not auto-chdir when
the given line is a directory, however you can
easily script this in:
`js
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:
`js`
▸ pwd
/Users/tj/projects/nshell
▸ node_modules/commander
▸ pwd
/Users/tj/projects/nshell/node_modules/commander
▸ ../..
▸ pwd
/Users/tj/projects/nshell
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:
`js
// $ 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;
}
});
`
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.
`js`
shell.on('command', function(e){
if ('' == e.line.trim()) {
e.preventDefault();
shell.exec(shell.lastCommand);
}
});
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":
`js
shell.on('command', function(e){
e.line = expansion(e.line);
});
function expansion(line) {
return line.replace(/(.*?)/, function(_, js){`
return eval('(' + js + ')');
});
}
Usage:
`
▸ echo
▸ 4294967296
▸ cat
test:
@./node_modules/.bin/mocha \
--require should \
--reporter spec
...
``
(The MIT License)
Copyright (c) 2012 TJ Holowaychuk <tj@vision-media.ca>
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.