Want to apply just a part of your patch(Only on few files or even a few lines)?

Starting tag = MY_PORTION_START
Ending tag = MY_PORTION_END

awk 'BEGIN {start=0} /MY_PORTION_END/ {start=0} {if (start == 1) print} /MY_PORTION_START/ {start=1}' patch.diff | patch -p 1

You have to insert these tags into your patch file depends on your need.

awk - One of the best tools in linux

I was searching for a tool/command in linux to remove all the duplicate lines from a file without sort the lines. And i came across this link (see the link below)...Its really amazing. We can do lots and lots of things using awk. Its one of the mostpowerful tools for file/string processing. I hope it will be useful for most of the software developers and testers. One more good thing is that awk is available for windows too.

Link: http://kaneda.bohater.net/faq/awk1line.txt.
The latest version of this file is here.