Where to find source so I can modify it?
Let me explain first what I do not need. I do not, at this time, need help learning C++, nor how to compile. Since I started on microprocessors in 1974, I have dealt with a lot of languages of various sorts, usually as an aid for troubleshooting embedded systems, not as a programmer. I have played with Ansi-C, and did produce for fun a simple one page impedance transformation program which was eventually authorized for official use in the contract defense plant where I retired, and assume I can start on my own with C++, perhaps with a tutorial or maybe that $13 package Sam's Club has for sale, and with elbow grease I can at least do simple things. My goals are not high, but I would at least like to see what the linux development guys really do.
No, what I am trying to understand is probably a very simple thing for you guys, but I just can't visualize it, and have been putting this off for several years becaused I can't visualize it. In my experience, when this happens, it's usually a simple thing that I am missing. Sigh.
I want to know generically where to find the existing source in the source packages available for download so I can study/modify it (Um, okay, mostly study it.) I assume it will be in the format produced by an editor, pico or emacs or vi or whatever, before the compile (gcc or whatever). If I have a source package for a linux app of some sort, how will I know it when I look at the files? I have seen *.o and *.h files and probably other files that I forget. Will it be the .o files? I am guessing .h files are libraries like those one specifies at the beginning of a C routine?
And, if I download an "automatic" source rpm for Drake, which apparently starts to compile and install itself instead of loading the files where there name states, how on earth do I access the source for this rpm? Do I run <rpm -qpl rpmname> and go where the files are listed?
I am admittedly slow, but I am steady, as the old saying goes. If I can find the files that look like the ones you guys show when you have a problem, I am confident I can learn the rest. Weird but true. :-)