What command would you use to search for a specific string in a file?

The command used to search for a specific string within a file is grep 'string' filename. The grep command stands for "Global Regular Expression Print" and is utilized in Unix and Linux systems to search through text by matching the specified pattern.

When you execute grep 'string' filename, the command reads the specified file line by line, looking for any lines that contain the exact string you provided. If any lines match, those lines will be printed to the terminal. This makes grep a powerful tool for finding and filtering text within files efficiently.

The other commands listed serve different purposes. The find command is generally used to search for files and directories within a file system based on criteria like name, size, or modification time, rather than searching within the content of a file. The search command does not exist in standard Linux command sets and is not recognized for this purpose. The look command is used to display lines in a sorted file that begin with a specified string but works only with sorted data and is not intended for searching text within arbitrary files. This context clarifies why grep is the correct choice.