sed issue with end of line

Shell Programming and Scripting
1

Example,

Trying to replace text to the end of a line.

Text file looks like this

PP= 4
PP= 412
PP= 425

I want to replace only the following line:

PP= 4

with

PP= 2

How can this be done with sed?

2 
sed 's/4$/2/' filename
3 
 sed s/"PP= 4"$/"PP= 2"/

between the " " whatever you want to replace

(edit: added the $
after the varontron remarks, varontron is right without it will change all PP= 4[whatever])

4

you need the '$' on the end of the pattern if you want only the line ending in '4' to be changed. Phil_FL's suggestion will change all the lines containing the pattern, not just the first.