Extract payload data from captured TCP stream

readtcpcap.sh

#!/bin/sh

#
# Example usage:
#     cat tcpdump.pcap | ./readtcpcap.sh 1 > stream1
#

if [ -z "$1" ]; then
	echo 'You have to specify a TCP stream!'
	exit 1
else
	stream=$1
fi

tshark -r '-' -Q -z "follow,tcp,raw,$stream" | \
head -n -1 | tail -n +7 | \
sed 's/^\s\+//g' | \
xxd -r -p