Question

Before I sit down and start hacking it out, I thought I’d come here and see if you all had any tips or even if something like this has been done before.

I want to re-create a basic shell like syntax within a python program. In other words, when people run the file with python, they will be greeted with a little prompt

>> 

For simple things, using an option parser to say

opt.parse_args(input.split(" "))

Works just fine, but now I would like to not only escape special characters like spaces with the ‘\’ character, but also treat quoted strings as a single argument, like in a unix shell.

Does there exist anything that might already help with this?

Thanks for any suggestions!
– Chase

Answer 1

Start with the shlex module:

$ pydoc shlex
Help on module shlex:

NAME
    shlex - A lexical analyzer class for simple shell-like syntaxes.

You can use it like this:

>> import shlex
>> shlex.split('This "is a" test.')
['This', 'is a', 'test']

This just splits things up into logical tokens; it won’t do anything like variable expansion and so forth. That’s still up to you, as is actually running commands.