grep - command-line utility for searching plain-text data sets for lines that match a regular expression.

Linux Aug 7, 2022

Command	Description
`grep SEARCH_PHRASE FILE_NAME.FILE_FORMAT`	Search for a given phrase in a file.
`grep SEARCH_PHRASE FILE_1_NAME.FILE_FORMAT FILE_2_NAME.FILE_FORMAT`	Search for a given phrase across multiple files.
`grep "##" MARKDOWN_FILE_1.FILE_FORMAT MARKDOWN_FILE_2.FILE_FORMAT`	Search for sub-headings in across multiple markdown files.
`grep "##" *.md`	Search for sub-headings in across all markdown files via glob pattern.

Command	Description
`grep -r SEARCH_PHRASE .`	Search for a phrase recursively from a given directory and explore all files and sub folders and files within those sub folders.
`grep -r SEARCH_PHRASE example/path/to/folder`	Search for a phrase recursively from a given directory and explore all files and sub folders and files within those sub folders.