gistfile1.sh

# most basic approach
find system -type f -exec sed -i -e "s/defined('SYSPATH') OR die('No direct access allowed.');//" '{}' \;

# case insensitive
find system -type f -exec sed -i -e "s/defined('SYSPATH') [oO][rR] die('No direct access allowed.');//" '{}' \;

# case insensitive with any die message
find system -type f -exec sed -i -e "s/defined('SYSPATH') [oO][rR] die('[^']\{0,\}');//" '{}' \;


# all the above and also remove extra whitespace and empty php directives
find system -type f -exec sed -i -e "{ s/^<?php\([ \t]\{1,\}\)defined('SYSPATH') [oO][rR] die('[^']\{0,\}');\(.\{0,\}\)$/<?php\1\2/ ; s/^<?php[ \t]\{1,\}$/<?php/ ; /^<?php[ \t]\{1,\}?>$/ d }" '{}' \;