Skip to content

Latest commit

 

History

History
74 lines (63 loc) · 3.21 KB

index.rst

File metadata and controls

74 lines (63 loc) · 3.21 KB
Raw

Plumbum: Shell Combinators

Ever wished the wrist-handiness of shell scripts be put into a real language? Say hello to Plumbum Shell Combinators. Plumbum (Latin for lead, which was used to create pipes back in the day) is a small yet feature-rich library for shell script-like programs in Python. The motto of the library is you'd never have to resort to shell scripts again, and thus it attempts to mimic the shell syntax (but only where it makes sense) while keeping it cross-platform.

Apart from shell-like syntax and nifty shortcuts, the library focuses on local and remote command execution, local and remote paths, and working directory and environment manipulation. But enough with the talk, let's see some code!

>>> from plumbum import local, FG, BG
>>> from plumbum.local import ls, grep, cat, wc
>>>
>>> ls()
'LICENSE\nREADME.rst\ndist\ndocs\nplumbum\n[...]'
>>>
>>> chain = ls | wc["-l"]
>>> print chain
(C:\Program Files\Git\bin\ls.exe | C:\Program Files\Git\bin\wc.exe '-l')
>>> chain()
'9\n'
>>>
>>> ls["-l"] & FG
total 10
-rw-r--r--    1 sebulba  Administ     1079 Apr 29 15:34 LICENSE
-rw-r--r--    1 sebulba  Administ     1318 Apr 29 16:56 README.rst
drwxr-xr-x    2 sebulba  Administ        0 Apr 29 16:59 dist
drwxr-xr-x    5 sebulba  Administ     4096 Apr 29 23:38 docs
drwxr-xr-x    2 sebulba  Administ     4096 Apr 29 16:52 plumbum
[...]
>>> (ls["-a"] | wc["-l"]) & BG
<Future ['C:\\Program Files\\Git\\bin\\wc.exe', '-l'] (running)>

There's much more Plumbum can do, so be sure to read on:

.. toctree::
   :maxdepth: 2

   local_commands
   local_machine
   paths
   remote_machine
   cli
   api

About

The original purpose of Plumbum was to enable local and remote program execution with ease, assuming nothing fancier than good-old SSH. On top of this, a file-system abstraction layer was devised, so that working with local and remote files would be seamless.

I've toyed with this idea for some time now, but it wasn't until I had to write build scripts for a project I've been working on that I decided I've had it with shell scripts and it's time to make it happen. Plumbum was born from the scraps of the Path class, which I wrote for the aforementioned build system, and the SshContext and SshTunnel classes that I wrote for RPyC. When I combined the two with shell combinators (because shell scripts do have an edge there) the magic happened and here we are.

Credits

The project has been inspired by PBS of Andrew Moffat, and has borrowed some of his ideas (namely treating programs like functions and the nice trick for importing commands). However, I felt there was too much magic going on in PBS, and that the syntax wasn't what I had in mind when I came to write shell-like programs. I contacted Andrew, but he wanted to keep PBS this way. Other than that, the two libraries go in different directions.

Plumbum pays tribute to Rotem Yaari who suggested a library code-named pyplatform for that very same purpose, but it had never materialized.