Which command is used in the Linux operating system for string searches across multiple directories?

The command used in the Linux operating system for searching for strings across multiple directories is GREP. GREP stands for "Global Regular Expression Print" and is specifically designed for searching plain-text data sets for lines that match a regular expression. When combined with options like -r, it can recursively search through all files in a specified directory and its subdirectories, making it very powerful for searching strings in multiple directories.

Other commands like DD are primarily used for low-level copying and conversion of raw data, while LIST and STRINGS serve different purposes: LIST is not a standard command in Linux for searching strings, and STRINGS is used to extract printable strings from binary files rather than searching through directories.