A sourceable Bash plugin for debugging scripts. Source it near the top of a
script; it installs ERR and EXIT traps and, on failure, prints the
filename, line number, error message, failing command, a short code snippet,
and the call stack.
trapper.sh must be sourced, not executed. By default it turns on
set -Eeuo pipefail. Set TRAPPER_SET_STRICT=0 before sourcing if the host
script already manages set options.
Colour follows NO_COLOR, FORCE_COLOR, and whether stdout is a TTY.
source src/trapper.shTrapper can report errors in several layouts:
| Scenario | Requirements | Results |
|---|---|---|
| Single script | Include trapper.sh |
Reports filename, line number, command, snippet, and stack. |
| Executing scripts | Include trapper.sh in every script |
Each process reports its own failure; the parent then reports the failing child. |
| Including scripts | Include trapper.sh only in the parent |
Reports filename, line number, snippet, and stack of the failing sourced script. |
Each demo lives in its own directory under demos/. Run the entry script
from any working directory. They are meant to fail.
A missing path, so the ERR trap sees real stderr:
demos/command-failure/command-failure.sh
A parent that runs child scripts, with the error in the last child:
A parent that sources child scripts, with the error in the last child:
make init # first-time makefile-skills checkout
make check # bash -n, ShellCheck, and tests/run_all.sh