ed is the standard text
editor. If the named file does not exist,
ed creates it; otherwise, the
existing file is opened for editing. As a
line editor, ed is generally no
longer used because vi and
ex have superseded it. However,
it can be useful from a slow dial-in connection or over an
intercontinental ssh session
when using a screen editor is painful. Some utilities, such as
diff, continue to make use of
ed command syntax.
Set string as the prompt for
commands (default is
P command turns the
prompt display on and off.
Suppress character counts, diagnostics, and the
! prompt for shell
commands. Earlier versions of ed used plain
-; this is still accepted.
-x, but assume
file began in encrypted form. Solaris
Forces backwards compatibility. This affects the
!!. GNU/Linux only.
Supply a key to encrypt or decrypt file using crypt. Solaris and Mac OS X only.