#!/bin/sh
self=`basename $0`
openTime="22000d"
[ "$1" ] || { cat <<EOS >&2
Hold specified port or file open -- 12/10/17 brent@mbari.org
Usage:
  $self <portFile> {openTime}
First argument is the port or file to hold open
Remaining args are passed to the 'sleep' command
If openTime is omitted, the port or file is held open forever (i.e. $openTime)
Examples:
  $self /dev/ttyA6         #hold ttyA6 open forever
  $self /dev/ttyA6 1h 30m  #hold ttyA6 open for 1hr and 30 minutes
Note:
  Close the port with:
    fuser -k <portFile>
EOS
  exit 2
}

portFile=$1
[ -r "$portFile" ] || {
  echo "$0:  Cannot read $portFile" >&2
  exit 1
}
shift
[ "$2" ] || set $openTime
nohup sh -c "exec sleep $* <$portFile" >/dev/null 2>&1 &