Preserve Expensive Command Output

Capture output when it will be useful during or after a slow command. For servers, watchers, and ongoing log streams, prefer the harness's managed background-process tool instead of a shell pipeline.

Pattern

Choose a repository-approved ignored path, then preserve both displayed and saved output:

mkdir -p tmp
command 2>&1 | tee tmp/descriptive-command.log

Use set -o pipefail or inspect the producer's pipeline status when command success matters; tee succeeding does not prove the original command succeeded.

Name logs by purpose and stable identifier so concurrent runs do not overwrite one another. Avoid recording credentials or sensitive response data.

Do not add tee mechanically to fast commands or output that will be consumed only once. Avoid truncating a live producer with head unless early SIGPIPE termination is intended.