#!/bin/bash

E_OK=0;E_WARNING=1;E_CRITICAL=2;E_UNKNOWN=3

usage()
{
cat <<EOF
Usage: $0 remotehost filename
This script checks differecies of local and remote files
EOF
}

if [[ -z "$1" |]]; then usage; exit $E_UNKNOWN
 else  serv="$1"
fi

if [[ -z "$2" |]]; then usage; exit $E_UNKNOWN
 else fname="$2"
fi

difs="$(diff $fname <(ssh "$serv" "cat $fname"))"

if [[ "$?" -eq "1" |]]
 then
  echo "CRITICAL: File $fname. Local and on host $serv has differencies"
  echo "$difs"
  exit $E_CRITICAL
fi

echo "OK: File $fname. Local and on host $serv has no differencies"
exit $E_OK