How to grep and replace

Question

Another option is to use find and then pass it through sed.

find /path/to/files -type f -exec sed -i 's/oldstring/new string/g' {} \;

I got the answer.

grep -rl matchstring somedir/ | xargs sed -i 's/string1/string2/g'

You could even do it like this:

Example

grep -rl 'windows' ./ | xargs sed -i 's/windows/linux/g'

This will search for the string 'windows' in all files relative to the current directory and replace 'windows' with 'linux' for each occurrence of the string in each file.

This works best for me on OS X:

grep -r -l 'searchtext' . | sort | uniq | xargs perl -e "s/matchtext/replacetext/" -pi

Source: http://www.praj.com.au/post/23691181208/grep-replace-text-string-in-files

Usually not with grep, but rather with sed -i 's/string_to_find/another_string/g' or perl -i.bak -pe 's/string_to_find/another_string/g'.

Other solutions mix regex syntaxes. To use perl/PCRE patterns for both search and replace, and only process matching files, this works quite well:

grep -rlIZPi 'match1' | xargs -0r perl -pi -e 's/match2/replace/gi;'

match1 and match2 are usually identical but match1 can be simplified to remove more advanced features that are only relevant to the substitution, e.g. capturing groups.

Translation: grep recursively and list matching filenames, each separated by nul to protect any special characters; pipe any filenames to xargs which is expecting a nul-separated list; if any filenames are received, pass them to perl to perform the actual substitutions.

For case-sensitive matching, drop the i flag from grep and the i pattern modifier from the s/// expression, but not the i flag from perl itself. Remove the I flag from grep to include binary files.

Be very careful when using find and sed in a git repo! If you don't exclude the binary files you can end up with this error:

error: bad index file sha1 signature 
fatal: index file corrupt

To solve this error you need to revert the sed by replacing your new_string with your old_string. This will revert your replaced strings, so you will be back to the beginning of the problem.

The correct way to search for a string and replace it is to skip find and use grep instead in order to ignore the binary files:

sed -ri -e "s/old_string/new_string/g" $(grep -Elr --binary-files=without-match "old_string" "/files_dir")

Credits for @hobs