How do I search for a string in multiple files in Linux?

To search multiple files with the grep command, insert the filenames you want to search, separated with a space character. The terminal prints the name of every file that contains the matching lines, and the actual lines that include the required string of characters. You can append as many filenames as needed.

How do I find and replace text in multiple files?

Remove all the files you don’t want to edit by selecting them and pressing DEL, then right-click the remaining files and choose Open all. Now go to Search > Replace or press CTRL+H, which will launch the Replace menu. Here you’ll find an option to Replace All in All Opened Documents.