#pentest #recipe: clean escape sequence codes from 'script' log

script_strip

#!/bin/bash

#-----------------------------------------------------------------------------
# Preconditions:
#
#  You have a `script` command outputfile (typescript by default)
#
# 	$ script
# 	Script started, file is typescript
# 		<-- your commands and output here -->
# 	$ exit
# 	Script done, file is typescript

if [ -z "$1" ]; then 
	echo usage: $0 file
	exit
fi

FILE=$1
LINES=`wc -l ${FILE} | cut -d' ' -f1`

# screen session name --> $PID.strip
SESSION=${$}.strip

#-----------------------------------------------------------------------------
# Problem:
#
#  Script output contains escape sequence codes and other non-readable data
#  filtering or escaping with regexes is not an option (ex. cursor movement)

#-----------------------------------------------------------------------------
# Solution:
#
#  Use screen hardcopy to copy output file contents after escape sequence 
#  interpretation 
#  (thxs to: http://superuser.com/questions/99128/removing-the-escape-\
#	         characters-from-gnu-screens-screenlog-n)

#-----------------------------------------------------------------------------
# How to:
#
#  Create new screen session (de-attached)
screen -d -m -S ${SESSION}

#  Execute cat typescript in the created screen session 
#screen -S ${SESSION} -X scrollback ${LINES}
# XXX hardcoded scrollback debug and fix
screen -S ${SESSION} -X scrollback 50000
screen -S ${SESSION} -p 0 -X stuff "cat ${FILE}\n"

sleep 0.5

# grab hardcopy of screen session buffer
# note: maybe its better to calculate typescript size and specify a buffer
screen -S ${SESSION} -X hardcopy -h .${FILE}.tmp

# finish session
screen -S ${SESSION} -X quit

# trim results to only get the script session output
sed -n -e '/^Script started on /,/^Script done on / p' .${FILE}.tmp > ${FILE}.clean

# add controls
rm .${FILE}.tmp