UNIX for Advanced & Expert Users

#!/bin/sh
# megasend.sh -- for the sending system.

SOURCE="./source"
OUTPUT="output"

# 50 binary gigabytes.  Guessing low since overfilling the drive
# would mean data loss.
MAXBLOCKS="$((1024*1024*50))"

trap "rm -f /tmp/$$-fifo" EXIT

mkfifo /tmp/$$-fifo
tar -cf /tmp/$$-fifo "$SOURCE" &

PART=1

while true
do
        # Check for EOF by reading one sector
        dd of=/tmp/$$ bs=1024 count=1 2>/dev/null
        [ -s "/tmp/$$" ] || break # Quit if /tmp/$$ is an empty file

        echo "Hit enter when drive is ready to store part $PART"
        read REPLY </dev/tty

        # Don't let the drive run out of space here.  Guess a little low.
        ( cat /tmp/$$ ; dd bs=1024 count=$MAXBLOCKS ) >"$OUTPUT" 2>/dev/null

        ls -lh output
        echo "Part $PART is now ready"
        ((PART++))
done < /tmp/$$-fifo

#!/bin/bash
# megaget.sh -- for the receiving system.

function die
{
        echo "$@" >&2
        exit 1
}

SOURCE="./output"
DEST="dest/"

[ -d "$DEST" ] || die "No such folder $DEST"

PART=1
while true
do
        echo "Hit enter when drive containing part $PART is ready" >&2
        read REPLY </dev/tty

        # Check for EOF by looking for blank file
        [ -e output ] || break

        ls -lh "$SOURCE" >&2
        cat "$SOURCE"

        echo "Part $PART restored" >&2

        ((PART++))
done | tar -C "$DEST" -xf -