'timeout' command, implemented within the shell so that it works with shell functions

timeout_fn.sh

#!/bin/zsh
# A version of the 'timeout' command that works with shell functions
#
# Usage:
#     source timeout_fn.sh
#     timeout_fn DURATION COMMAND [ARG]...

timeout_fn () {
  local timeout=$1
  shift
  eval "$@" &
  SLOW_PID=$!
  { `#timeout` sleep $timeout; kill $SLOW_PID 2>&1 | grep -v 'no such process' >&2; exit 124; } &
  wait $SLOW_PID
}


## Test only
#
#test_fn () {
#  echo start
#  sleep $1
#  echo done
#  return 1
#}
#
#echo slow command:
#timeout_fn 1 test_fn 5
#echo Returned: $?
#
#echo fast command:
#timeout_fn 5 test_fn 1
#echo Returned: $?