# ex > Command-line text editor. > See also: `vim`. > More information: . - Open a file: `ex {{path/to/file}}` - Save and Quit: `wq` - Undo the last operation: `undo` - Search for a pattern in the file: `/{{search_pattern}}` - Perform a regular expression substitution in the whole file: `%s/{{regular_expression}}/{{replacement}}/g` - Insert text: `i{{text}}` - Switch to Vim: `visual`