The best way to familiarize yourself with an inher

Question

Stacker Nobody asked about the most shocking thing new programmers find as they enter the field.

Very high on the list, is the impact of inheriting a codebase with which one must rapidly become acquainted. It can be quite a shock to suddenly find yourself charged with maintaining N lines of code that has been clobbered together for who knows how long, and to have a short time in which to start contributing to it.

How do you efficiently absorb all this new data? What eases this transition? Is the only real solution to have already contributed to enough open-source projects that the shock wears off?

This also applies to veteran programmers. What techniques do you use to ease the transition into a new codebase?

I added the Community-Building tag to this because I'd also like to hear some war-stories about these transitions. Feel free to share how you handled a particularly stressful learning curve.

Answer 1

create documentation for each thing you figured out from the codebase. find out how it works by exprimentation - changing a few lines here and there and see what happens. use geany as it speeds up the searching of commonly used variables and functions in the program and adds it to autocomplete. find out if you can contact the orignal developers of the code base, through facebook or through googling for them. find out the original purpose of the code and see if the code still fits that purpose or should be rewritten from scratch, in fulfillment of the intended purpose.

find out what frameworks did the code use, what editors did they use to produce the code.

the easiest way to deduce how a code works is by actually replicating how a certain part would have been done by you and rechecking the code if there is such a part.

it's reverse engineering - figuring out something by just trying to reengineer the solution.

most computer programmers have experience in coding, and there are certain patterns that you could look up if that's present in the code.

there are two types of code, object oriented and structurally oriented.

if you know how to do both, you're good to go, but if you aren't familiar with one or the other, you'd have to relearn how to program in that fashion to understand why it was coded that way.

in objected oriented code, you can easily create diagrams documenting the behaviors and methods of each object class.

if it's structurally oriented, meaning by function, create a functions list documenting what each function does and where it appears in the code..

i haven't done either of the above myself, as i'm a web developer it is relatively easy to figure out starting from index.php to the rest of the other pages how something works.

goodluck.

Answer 2

I've dealt with this issue many times. I ended up writing a blog post about a general process to follow for learning a new codebase: http://www.larsavery.com/blog/a-process-for-learning-a-new-codebase/