enhance - A program that adds command-line editing to third party programs.
enhance command [ argument ... ]
program provides enhanced command-line editing facilities to
users of third party applications, to which one doesn't have any source code.
It does this by placing a pseudo-terminal between the application and the real
terminal. It uses the tecla command-line editing library to read input from
the real terminal, then forwards each just completed input line to the
application via the pseudo-terminal. All output from the application is
forwarded back unchanged to the real terminal.
Whenever the application stops generating output for more than a tenth of a
second, the enhance
program treats the latest incomplete output line as
the prompt, and redisplays any incompleted input line that the user has typed
after it. Note that the small delay, which is imperceptible to the user, isn't
necessary for correct operation of the program. It is just an optimization,
designed to stop the input line from being redisplayed so often that it slows
Note that the user-level command-line editing facilities provided by the Tecla
library are documented in the tecla(7)
The one major problem that hasn't been solved yet, is how to deal with
applications that change whether typed input is echo'd by their controlling
terminal. For example, programs that ask for a password, such as ftp and
telnet, temporarily tell their controlling terminal not to echo what the user
types. Since this request goes to the application side of the psuedo terminal,
program has no way of knowing that this has happened, and
continues to echo typed input to its controlling terminal, while the user
types their password.
Furthermore, before executing the host application, the enhance
initially sets the pseudo terminal to noecho mode, so that everything that it
sends to the program doesn't get redundantly echoed. If a program that
switches to noecho mode explicitly restores echoing afterwards, rather than
restoring the terminal modes that were previously in force, then subsequently,
every time that you enter a new input line, a duplicate copy will be displayed
on the next line.
libtecla.a - The tecla library.
~/.teclarc - The tecla personal customization file.
Martin Shepherd (firstname.lastname@example.org)