Alternative sleep implementation

sleep.sh

#!/bin/sh


Help()
{
    cat <<-EOF
Usage: $0 NUMBER[SUFFIX]...
  or:  $0 OPTION
Pause for NUMBER seconds.  SUFFIX may be 's' for seconds (the default),
'm' for minutes, 'h' for hours or 'd' for days.  NUMBER need not be an
integer.  Given two or more arguments, pause for the amount of time
specified by the sum of their values.

      --help     display this help and exit
EOF
}

if [ $# -eq 0 ]; then
    echo "$0: missing operand"
    echo "Try 'sleep --help' for more information"
    exit 1
fi

ARGS=`getopt -o h --long help -n "$0" -- "$@"`
if [ $? != 0 ]; then
    echo "Terminating..."
    exit 1
fi

eval set -- "${ARGS}"

while true
do
    case "$1" in
        -h|--help)
            Help
            exit 0
            ;;
        --)
            shift
            break
            ;;
        *)
            echo "Internal Error!"
            exit 1
            ;;
    esac
done

sleep_time=`echo "$@"|awk '
{
    sum = 0;
    flag = 0;
    for (i = 1; i <= NF; i++) {
        switch($i) {
            case /inf/:
            case /infinty/:
                flag = 1;
                exit;
            case /.*d/:
                sum += $i * 86400;
                break;
            case /.*h/:
                sum += $i * 3600;
                break;
            case /.*m/:
                sum += $i * 60;
                break;
            default:
                sum += $i;
                break;
        }
    }
} END {
    if (flag) {
        print "infinty"
    } else {
        print sum
    }
}'`

if [ "$sleep_time" != "infinty" ]; then
    exec flock -sF "$0" flock -w $sleep_time -E 0 -eF "$0" true
else
    exec flock -sF "$0" flock -eF "$0" true
fi