Regarding the grep command

Question

I am trying to change the copyright headers in my assignment. I was able to list all files with copyright headers using the following commmand:

grep -rni copyright * 

In the above command, I got about 1000 files.

Can anyone help me how to change all files in one go?

Answer 1

This will apply the text change to files with the word "copyright" in them (case insensitive):

 for filename in *; do if grep -qi "copyright" "$filename"; then sed -i'' -e 's/old text/new text/' "$filename" fi done 

Please note that this only works in the current directory. To process files in subdirectories, you probably want to use the find .

If you can describe the text change you want to make, we can offer more precise methods to achieve your goal.

Answer 2

 grep -ril copyright * | xargs sed -i 's/old text/new text/' 

Answer 3

There is a simple tool called headache . I found it quite useful to solve this problem. Available on Debian and Ubuntu at least.