#!/bin/bash

_help() {
   echo '# Scotty v.5

Scotty is the most simple network file transfer utility. It provides
no security what so ever.

To expose a file/folder for anyone to catch:
* scotty up [folder/file name]
* Pick the hostname from the printed list, and send it to the receiver.

To download the exposed folder/file:
* scotty down [sender host name]
* Download happens to the current working directory. 
* By default, any existing file is overwritten.

Add tar options by modifying a variable:
* SCOTTY_TAR="pass your tar options here" scotty ...

Scotty uses port '$PORT' to transfer files. Downloading host needs
to see the uploader directly.
'
exit     
}

PORT=60006
[[ -z "$2" ]] && _help
[[ "$1" = "-h" ]] && _help

PV=cat
which pv &> /dev/null && PV=pv

[[ "$1" = up ]] && {
echo Beam me up, Scotty. Waiting for someone to beam $( hostname ) down...
printf "\n| %15s | %s\n" IP Hostname
for addr in $( hostname -I ); do
    printf "| %15s | %s\n" $addr $( dig +short -x $addr )
done
echo Scotty, beam $( hostname ) down | nc -l $PORT
echo Transporter locking to signature
tar -cv $SCOTTY_TAR "$2" | $PV | nc -l $PORT
}
[[ "$1" = down ]] && {
nc -w 10 "$2" $PORT
sleep 0.5
nc -w 10 "$2" $PORT | $PV | tar -x $SCOTTY_TAR
}
true