Sagasu - search for text inside files in Linux MintTools
Allows you to select files by mask, search in subdirectories.
Sagasu has a simple and intuitive interface. In fact, you need only to specify the directory and the search string. You can use Perl regular expressions to search for whole words, case sensitive characters, to set the depth of search directories, to exclude directories CSV and instruct them not to follow symbolic links.
The search results can be opened in different tabs and switch between them.
Installation into Linux Mints:
sudo apt-get install sagasu