Using Cscope and SilentBob to analyze source code
When you start learning the source code of an unfamiliar project, you don't have the knowledge of its structure or the meaning of specific functions, classes, and units in the project. You can use tags to browse for definitions, but it's hard to get an overall picture by just looking through every definition one by one. Cscope and SilentBob are two tools that can help you analyze unfamiliar source code. They help you find symbol definitions, determine where specific functions are used, determine which functions are called by other given functions, and search for strings and patterns throughout the code base. With them, you can save time by doing fast, targeted searches instead of grepping through source files by hand.
Cscope is a popular utility, and most modern distributions include it. Although Cscope was originally intended only for use with C code, it actually works well with languages like C++ and Java. Cscope comes with an ncurses-based GUI, but it also supports a command-line interface to communicate with other application that can be used as front ends, including major editors such as Emacs and Vim.
SilentBob is another new tool for analyzing source code. It currently supports C/C++, Perl, and Python, but its plugin framework (which is not documented at the moment) enables users to add support for new languages and other features easily.