ex (text editor)

ex, short for EXtended, is a line editor for Unix systems originally written by Bill Joy^[1] in 1976, beginning with an earlier program written by Charles Haley.^[2]

The original ex was an advanced version of the standard Unix editor ed, included in the Berkeley Software Distribution. ex is similar to ed, with the exception that some switches and options are modified so that they are more user-friendly.

ex was eventually given a screen oriented visual interface (adding to its command line oriented operation), thereby becoming the vi text editor. In recent times, ex is implemented as a personality of the vi program; most variants of vi still have an "ex mode", which is invoked using the command ex, or from within vi for one command by typing the : (colon) character. Although there is overlap between ex and vi functionality, some things can only be done with ex commands, so it remains useful when using vi.

The core ex commands which relate to search and replace are essential to vi. For instance, the ex command issued from vi :%s/XXX/YYY/g replaces every instance of XXX with YYY. The % means every line in the file. The 'g' stands for global and means replace every instance on every line (if it was not specified, then only the first instance on each line would be replaced).

ex has a synonym e in HP-UX environments.

Switches

ex recognises the following switches:

• - (obsolete) suppresses user-interactive feedback
• -s (XPG4 only) suppresses user-interactive feedback
• -l sets lisp editor option
• -r recover specified files after a system crash
• -R sets readonly
• -t tag Edit the file containing the specified tag
• -v invoke visual mode (vi)
• -w set window size n
• -x set encryption mode
• -C encryption option
• file specifies file to be edited

See also

• List of Unix programs

External links

• ex: text editor – Commands & Utilities Reference, The Single UNIX® Specification, Issue 7 from The Open Group

Notes