failing like never before


GNU Readline

I reccently wrote a shell for a project in my CS class. One of the advanced features that my partner and I implmented in the shell, was tabbed completion, and in order to implemet this extremely useful shell feature, we used the GNU readline library. The GNU Readline library is a beast, and not in the good way. Its a great hulking pile of code and documentation, intended to provide a ton of features for reading typed lines. Once you figure out what all the function pointers, bindings, and generators in the Readline library are supposed to do, things become much more straightfoward, but it doesn't negate the fact that initially figuring out Readline is a bit of a pain in the butt.

The first thing I did after we were told that the Readline library could make our project easier to design, was to pop open a terminal and type "man readline". What I got was a basic summary of Readline, so in order to get the full library manual I had to resort to Google. I did however, happen to see this at the bottom of the manpage:


It's too big and too slow.

Now if even the guys working on the Readline library think thats its too big and too slow, we may have a potential problem on our hands.

One of the plus sides of however Readline's enormity was that it does offer a whole slew of features, like a kill ring, and generators for tab-completion of filenames and usernames. It would be very nice though, if all these features could be implemented without the need for a manual that probably took me longer to read, then it did for me to code up a generator for command line completion.

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