How to replace a whole line with sed?

Question

Suppose I have a file with lines

aaa=bbb

Now I would like to replace them with:

aaa=xxx

I can do that as follows:

sed \"s         


        

Answer 1

You can also use sed's change line to accomplish this:

sed -i "/aaa=/c\aaa=xxx" your_file_here

This will go through and find any lines that pass the aaa= test, which means that the line contains the letters aaa=. Then it replaces the entire line with aaa=xxx. You can add a ^ at the beginning of the test to make sure you only get the lines that start with aaa= but that's up to you.