ts — prepend a timestamp to every line of stdin

linux-ts.sh

# ts — timestamp every line of stdin (from moreutils)
# sudo apt install moreutils

command | ts                              # May 25 13:01:02 <line>
command | ts '[%H:%M:%S]'                 # [13:01:02] <line>
command | ts '[%Y-%m-%dT%H:%M:%S]'       # [2024-05-25T13:01:02] <line>
command | ts -s '%.s'                     # relative: seconds since last line

# The full AI logging pattern — timestamp, merge stderr, save + display:
agent-command 2>&1 | ts '[%H:%M:%S]' | tee run.log

# Replay a log with delays to see where time was spent:
while IFS= read -r line; do sleep 0.1; echo "$line"; done < agent.log \
  | ts -s '%.s'