#!/bin/sh
# Give a free ID to use

lastID=`tail -1 /etc/IDs | cut -d' ' -f1`
freeID=`expr $lastID + 1`

if [ $freeID -lt 10 ]
then
   echo -e "Next free ID: 000$freeID\n"

elif [ $freeID -lt 100 ]
then
   echo -e "Next free ID: 00$freeID\n"

elif [ $freeID -lt 1000 ]
then 
   echo -e "Next free ID: 0$freeID\n"

else
   echo -e "Next free ID: $freeID\n"

fi

