Tribblix: manual page: enhance.1

ENHANCE(1) User Commands ENHANCE(1)

NAME

enhance - enhanced command-line editing facilities

SYNOPSIS

enhance command [argument]...

DESCRIPTION

The enhance 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 re-displays any incompleted input line
that the user has typed after it. 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 re-displayed so often that it slows down output.

The user-level command-line editing facilities provided by the Tecla
library are documented in the tecla(7) man page

DEFICIENCIES

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 pseudo terminal, the enhance 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
program 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.

FILES

/usr/lib/libtecla.so
tecla library

~/.teclarc
tecla personal customization file.