What is it?

TBD (Tmux Bash Debugger) is a simple debugger for Bash that can be used to interactively inspect or debug the execution of a Bash script. It's meant to be source'ed into your script at the place where you want a break point to be set. Once at the break point, TBD will take over and run in a separate tmux window, from which you can interact and explore the execution environment of the script.

NOTE: TBD temporarily set +eu for the duration of a debugging session.

TBD uses separate tmux windows as debugging REPLs; one for the script's process, and one for each subshell created by the script. This not only leaves the script's terminal alone for direct user interactions, but it also makes it possible to debug a shell pipeline, which could have multiple subshells running as parallel processes.

Multiple and conditional break points are possible by sourcing TBD multiple times in the script. Setting conditional break points at runtime is also possible with the caveat that a break point set from a subshell on its parent process will have no effects.

See the examples/fizzbuzz script and /help for details.

Check out the demo

Prerequisites

You need to be running in a tmux session already, and have bat, less, and tmux in PATH. Of course, you should know how to use tmux; at least, you should know how to switch between tmux windows.

Installation and Usage

Currently, there's no automatic installation; just clone the repo, add tbd.sh and tbd-view somewhere in PATH, and make both executable. For example:

git clone git@github.com:kjkuan/tbd.git
cd tbd && PATH=$PWD:$PATH

To use it, simply source tbd.sh somewhere in your script, and run your script from a tmux window; follow the on-screen help, or enter /help, for instructions. See also the demo above.