Progress-based timeout

io-timeout.sh

#!/usr/bin/env bash

# This is an alternative for the GNU coreutils timeout, which resets the timer
# when the program writes to stdout. This allows setting much smaller timeout
# values for programs that regularly print progress messages, which allows
# progress stalls to be detected more quickly, saving execution time in testing
# contexts.

set -e

tmp=$(mktemp -d)
trap 'rm -rf -- "$tmp"' EXIT

fifo=$tmp/fifo
mkfifo $fifo

timeout=$1
shift

last_updated=$(date +%s)

"${@}" > $fifo &
pid=$!

while IFS= read -t $timeout -r line; do
    echo "$line"
    last_updated=$(date +%s)
done < $fifo

if [ $(( $(date +%s) - $last_updated )) -ge $timeout ]; then
    echo "Timeout: no activity for $timeout seconds"
    kill $pid
    wait -n
    exit 124
fi

wait ${pid}
exit $!