For questions pertaining the ex utility, a line-oriented text editor first developed by Bill Joy in 1976. The ex editor was later extended with a "visual mode", which turned into the vi screen editor. Use this tag for questions about ex itself, using ex, or questions about issues arising from the usage of utility itself.
ex is a line editor which serves as the foundation of vi. ex commands work on the current line or on a range of lines in a file. ex is invoked using the colon syntax within vi, and can be invoked on its own from the shell.
External reference
ex specification (The Open Group Base Specifications Issue 7, 2018 edition)
