How to write minimal command line interface?

kandelabr has asked for the wisdom of the Perl Monks concerning the following question:

For now I wrote a scarry while() loop with "parsing" done by regular expressions and Term::ReadLine for prompt/editing/command history.

For example: if(/^l (\w+)/) implements command 'l' that accepts an argument (nevermind detail such as validating input for now).

I am sure that this is not the best way to implement input handling but I am stucked, and google/cpan gladly supply too many links to psh. Psh is neat, but I know enough perl to use Term::Readline, and not quite enough to get ideas from much bigger programs. Melp!

- Maciek

Comment on How to write minimal command line interface?

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Re: How to write minimal command line interface? by Aristotle (Chancellor) on Dec 27, 2003 at 06:24 UTC
Maybe you're looking for Term::Shell? Makeshifts last the longest.	[reply]
Re: Re: How to write minimal command line interface? by shushousukuriputo (Initiate) on Dec 29, 2003 at 13:03 UTC
Instead of using Term::Shell you might want to use PPM::Term::Shell or copy the PPM::Term::Shell.pm into Term::Shell.pm. Same module, but the latter is a newer version.	[reply]
Re: How to write minimal command line interface? by bl0rf (Pilgrim) on Dec 28, 2003 at 02:26 UTC
It really depends on what you want to achieve with this shell. If you have a reliable shell you want to piggyback then your approach is as good as mine... (except instead of having a regex for each command, do the UNIX modular design: make some small commands and one regex for a whole group of them) If you want to enhance a shell ( DOS comes to mind ) you need to decide what to emulate. Make some recursive subs that break a command into parts, emulate pipes "\|" by openning things with `open(PRINTER, "\| lpr -Plp1")` Perl pipe opens, emulate file io ">","<" with... I guess pipe opens again. To run commands you can have a variable with the directory that contains all the executables, upon command submittal you can check whether the typed command is one of those executables and then run it. My site	[reply] [d/l]
Re: How to write minimal command line interface? by delirium (Chaplain) on Dec 29, 2003 at 13:31 UTC
This style of a command line interface works well for me: `perl -e 'while(1) {print "::> "; $_=<STDIN>; print $/,eval $_ \|\| '0'; +print "\n$@"}'` [download] ...but perhaps you could tell us more about what you are trying to do, some code you have for it, etc.	[reply] [d/l]
Re: Re: How to write minimal command line interface? by kandelabr (Novice) on Dec 30, 2003 at 03:43 UTC
Ahh, thanks, that is neat! I want that shell to present some kind of user interface for inputting a very limited set of commands. These commands will controll display of logs from about 30 machines. I have logs cleaned up, and ready to be displayed in a sanitized state with some minimal statistics as number of connections, top 10 speakers, etc. The shell should be able to parse something like: use domain.com #select subset of data to work on show smtpproxy top10 #display top 10 smtpproxy users for domain.com Assume that in the above case I would have a smtpproxy function take the domain and the option (top10) as arguments, and display formated data. Term::Shell might be the answer, I missed it in my search somehow. At the same time I would be glad to use my own and learn something in the process. -- maciek	[reply]


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