age-of

#!/bin/sh
#
# Show the age in seconds of a running or completed command which
# was run under the age-track wrapper.  exit 0 if still running, 1 otherwise.

AGE_DIR="$HOME/.run/age"

me=`basename $0`

usage () {
  cat <<EOF >&2
Usage: $me [-n] COMMAND [ARGS]
  -n  Calculate age as if process was still running
EOF
  exit 1
}

if [ "$1" == -h ] || [ "$1" == --help ] || [ $# -eq 0 ]; then
  usage
fi

if [ "$1" = -n ]; then
  now=y
  shift
fi

cmd="$1"
shift

base_cmd=`basename "$cmd"`
cmd_dir="$AGE_DIR/$base_cmd"
start_file="$cmd_dir/start"
end_file="$cmd_dir/end"

if ! [ -d "$cmd_dir" ]; then
  echo "$cmd_dir does not exist; was the command run under age-track?" >&2
  exit 1
fi

if ! [ -e "$start_file" ]; then
  echo "$start_file does not exist; aborting." >&2
  exit 1
fi
start=$( cat "$start_file" )

if [ -e "$end_file" ]; then
  end=$( cat "$end_file" )
  exit=1 # command not running
  if [ "$end" -lt "$start" ]; then
    echo "Command still running." >&2
    end=$( date +"%s" )
    exit=0
  fi
else
  # no end file, must still be running
  echo "Command still running." >&2
  end=$( date +"%s" )
  exit=0
fi

if [ -n "$now" ]; then
  end=$( date +"%s" )
fi

echo $(( end - start ))
exit $exit