tags is a utility, closely associated with (but not, AFAIK, restricted to use with) vi and vim, "VI iMproved".

The basic concept's pretty simple, when you run tags on a C source file, it will catalog all your functions and variables (and basically, anything else you can give a name to in C or C++) for you, which makes it easier down the road to debug your code (was hit_count an int or a long? In vi/ vim, run tags and it will save your current place and take you to the file and place in that file where you defined hit_count.)

Fire up vi or vim, and type in :help tags for how ta use it. Emacs *must* have a facility for working with tags, but it will take an infidel to fill you in on that =)

I've heard tell that Tom Christiansen wrote such a utility for use with Perl code, but it wasn't in the place I looked for it.

Philosophy can be made out of anything. Or less -- Jerry A. Fodor

I've cribbed together a utility to pull module info for use with ctags, so you can jump to a module's subroutine def as well as any subroutines you def in you code. Far from robust (doesn't handle "use libs", for just one example), but it's not hard to build. Tom's utility, no doubt, would work much better.

----Asim, known to some as Woodrow.

This implementation, Exuberant Ctags, is very nice, it even works on VMS systems. I use it all the time in combination with vim to navigate large heaps of messy C++. It turns your editor in something like a source browser. You can just 'click' on a function or class name and jump to its definition and then jump back to the original place again.

The output of ctags can be used for more things than just aiding an editor. The output is a list of imporant items in your program complete with a regular expression that can be used to find this item in the file. For C++ it even gives the relationships between classes.

With it, it is easy to write a Perl program that scans a ctags file and then shows you the class hierachy, what methods there are, or even the complexity of your code. The whole problem of parsing the code is taken care of by ctags. ctags is very useful.

Have Fun