Timestamped logging functions for scripts
Small log, warn and die helpers that write ISO timestamps to stderr and keep stdout clean for data.
- Bash
- GreenSnippets
- MIT
log() { printf '%s [INFO] %s\n' "$(date -u +%FT%TZ)" "$*" >&2; }
warn() { printf '%s [WARN] %s\n' "$(date -u +%FT%TZ)" "$*" >&2; }
die() { printf '%s [ERROR] %s\n' "$(date -u +%FT%TZ)" "$*" >&2; exit 1; }Example / expected output
log "Starting backup"
[[ -d /data ]] || die "/data does not exist"
<!-- 2025-03-01T10:15:00Z [INFO] Starting backup -->How it works
Writing logs to stderr keeps stdout usable for piping results. date -u +%FT%TZ gives an ISO 8601 UTC timestamp that sorts correctly and is unambiguous across machines. die logs and exits with a non-zero status so callers and CI notice.
This snippet has been reviewed but was not executed by an automated test. Test it in your own environment before relying on it.
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