One of the most commonly used debuggers for C-based and C++-based code is the GNU Debugger, or GDB for short. In the following example, we'll use this debugger due to it being both widely used and freely available. Originally written in 1986, it's now used with a wide variety of programming languages, and has become the most commonly used debugger, both in personal and professional use.

The most elemental interface for GDB is a command-line shell, but it can be used with graphical frontends, which also include a number of IDEs such as Qt Creator, Dev-C++, and Code::Blocks. These frontends and IDEs can make it easier and more intuitive to manage breakpoints, set up watch variables, and perform other common operations. Their use is, however, not required.

On Linux and BSD distributions, gdb is easily installed from a package, just as it is on Windows with MSYS2 and similar UNIX-like environments. For OS X/MacOS, one may have to install gdb using a third-party package manager such as Homebrew.

Since gdb is not normally code signed on MacOS, it cannot gain the system-level access it requires for normal operation. Here one can either run gdb as root (not recommended), or follow a tutorial relevant to your version of MacOS.