Reject a missing required configuration value.
Bash Scripts: Check a required value explicitly and emit a controlled diagnostic before exiting.
set -euo pipefail
if output=$(bash -u -c 'value=""; if [[ -z ${value:-} ]]; then printf "Required value missing\n"; exit 2; fi'); then
status=0
else
status=$?
fi
printf "%s (%s)\n" "$output" "$status"Expected output EXAMPLE
Required value missing (2)
Details
Requires Bash 4 or later. Save as snippet.sh and run bash snippet.sh in an empty working directory. Check a required value explicitly and emit a controlled diagnostic before exiting.
Tested on Ubuntu 24.04.5 LTS · · GNU bash, version 5.2.21(1)-release (x86_64-pc-linux-gnu) · bash 5.2.21-2ubuntu4; coreutils 9.4-3ubuntu6.3
Test inputs, results and environment
The exact published code ran in a dedicated Linux test container with prepared inputs. Snippet process uid 65534 with a read-only root filesystem and temporary working files. Networking disabled. Fixtures and output records are isolated from the application database. Testing covers this example and its stated checks, not every input, operating system, or runtime version. The Linux container shares its host's kernel; this is not a native Windows test.
- Architecture / host kernel
- x86_64 / 6.18.54.1-microsoft-standard-WSL2
- Snippet identity / locale
- uid=65534, gid=65534 (unprivileged process) / C.UTF-8
- Interpreter invocation
bash -euo pipefail -c <published code>- Container image ID
sha256:ec91410a8f6ec3e985830b5e3a0560306d36f8c1c5ccd91a6699abe707123fa3- Code SHA-256
33464d2a64ad1ed25ed6b42cc939fe42e22ce92ef0963ef6b7e1240623656bc1- Dependencies
- bash 5.2.21-2ubuntu4; coreutils 9.4-3ubuntu6.3
Test input setup
These are the prepared inputs used by the test harness. See Details above for the prerequisites and how to run this example.
# No input files required.
Observed standard output
Required value missing (2)
Exit code: 0. Standard error: empty. Validation: Exact stdout comparison. System-dependent values above are one recorded run.