https://github.com/developerstoolbox/trapper
An error trapper plugin for helping to debug bash scripts.
https://github.com/developerstoolbox/trapper
bash bash-debugging trapper wolfsoftware
Last synced: 4 months ago
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An error trapper plugin for helping to debug bash scripts.
- Host: GitHub
- URL: https://github.com/developerstoolbox/trapper
- Owner: DevelopersToolbox
- License: mit
- Created: 2021-06-09T13:30:01.000Z (over 4 years ago)
- Default Branch: master
- Last Pushed: 2025-09-01T07:58:38.000Z (4 months ago)
- Last Synced: 2025-09-01T10:02:14.946Z (4 months ago)
- Topics: bash, bash-debugging, trapper, wolfsoftware
- Language: Shell
- Homepage:
- Size: 243 KB
- Stars: 2
- Watchers: 0
- Forks: 0
- Open Issues: 3
-
Metadata Files:
- Readme: README.md
- Contributing: .github/CONTRIBUTING.md
- Funding: .github/FUNDING.yml
- License: LICENSE.md
- Code of conduct: .github/CODE_OF_CONDUCT.md
- Citation: CITATION.cff
- Codeowners: .github/CODEOWNERS
- Security: .github/SECURITY.md
Awesome Lists containing this project
README
## Overview
At Wolf Software we write a lot of bash scripts for many purposes and the one thing that we found lacking was a simple to use debugging tool.
Trapper is something that weas developed originally for internal use to debug scripts we release with the aim being a simple plugin that required minimal changes to the original script.
Trapper is capable of capturing a large array of runtime errors and attempts to point to where the error happened.
## Usage
Simply source trapper at the top of your script and then execute it as normal.
Trapper works by setting a trap for any errors and attempts to display where the errors happened.
> Truncated snippet
```
set -Eeuo pipefail
function trap_with_arg()
{
func="$1";
shift
for sig ; do
# shellcheck disable=SC2064
trap "$func $sig" "$sig"
done
}
trap_with_arg 'failure ${?}' ERR EXIT
```
It is capable of detecting errors in a many different scenarios.
| Scenario | Requirements | Results |
| ----------------- | ------------------------------------------ | -------------------------------------------------------------------------------------- |
| Single script | Include trapper.sh | Reports filename, line number and code snippet. |
| Executing scripts | Include trapper.sh (in all scripts) | Reports filename, line number and code snippet for full stack trace (calling scripts). |
| Including scripts | Include trapper.sh (only in parent script) | Reports filename, line number and code snippet of the failing included script. |
## Examples
### Testing for unset (unbound) variables
Single script attempt to use an unbound variable.
[Source](tests/unbounded/unbounded.sh)
### Testing execute stack (scripts calling scripts)
Parent script executing child script with error in the final child.
[Source](tests/execute-stack/parent.sh)
### Testing source stack (scripts including scripts)
Parent script including (sourcing) child scripts with an error in the final child.
[Source](tests/source-stack/parent.sh)
