From c2e5be2aa0fbd926b07f764ffbc8359d3246342f Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sat, 27 Apr 2024 14:43:23 +0200 Subject: Adding upstream version 8.1. Signed-off-by: Daniel Baumann --- examples/rlfe/README | 78 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 78 insertions(+) create mode 100644 examples/rlfe/README (limited to 'examples/rlfe/README') diff --git a/examples/rlfe/README b/examples/rlfe/README new file mode 100644 index 0000000..9e1f689 --- /dev/null +++ b/examples/rlfe/README @@ -0,0 +1,78 @@ +rlfe (ReadLine Front-End) is a "universal wrapper" around readline. +You specify an interactive program to run (typically a shell), and +readline is used to edit input lines. + +There are other such front-ends; what distinguishes this one is that +it monitors the state of the inferior pty, and if the inferior program +switches its terminal to raw mode, then rlfe passes your characters +through directly. This basically means you can run your entire +session (including bash and terminal-mode emacs) under rlfe. + +FEATURES + +* Can use all readline commands (and history) in commands that +read input lines in "canonical mode" - even 'cat'! + +* Automatically switches between "readline-editing mode" and "raw mode" +depending on the terminal mode. If the inferior program invokes +readline itself, it will do its own line editing. (The inferior +readline will not know about rlfe, and it will have its own history.) +You can even run programs like 'emavs -nw' and 'vi' under rlfe. +The goal is you could leave rlfe always on without even knowing +about it. (We're not quite there, but it works tolerably well.) + +* The input line (after any prompt) is changed to bold-face. + +INSTALL + +The usual: ./configure && make && make install + +Note so far rlfe has only been tested on GNU Linux (Fedora Core 2) +and Mac OS X (10.3). + +This assumes readline header files and libraries are in the default +places. If not, you can create a link named readline pointing to the +readline sources. To link with libreadline.a and libhistory.a +you can copy or link them, or add LDFLAGS='-/path/to/readline' to +the make command-line. + +USAGE + +Just run it. That by default runs bash. You can run some other +command by giving it as command-line arguments. + +There are a few tweaks: -h allows you to name the history file, +and -s allows you to specify its size. It default to "emacs" mode, +but if the the environment variable EDITOR is set to "vi" that +mode is chosen. + +ISSUES + +* The mode switching depends on the terminal mode set by the inferior +program. Thus ssh/telnet/screen-type programs will typically be in +raw mode, so rlfe won't be much use, even if remote programs run in +canonical mode. The work-around is to run rlfe on the remote end. + +* Echo supression and prompt recognition are somewhat fragile. +(A protocol so that the o/s tty code can reliably communicate its +state to rlfe could solve this problem, and the previous one.) + +* See the intro to rlfe.c for more notes. + +* Assumes a VT100-compatible terminal, though that could be generalized +if anybody cares. + +* Requires ncurses. + +* It would be useful to integrate rlfe's logic in a terminal emulator. +That would make it easier to reposition the edit position with a mouse, +integrate cut-and-paste with the system clipboard, and more robustly +handle escape sequence and multi-byte characters more robustly. + +AUTHOR + +Per Bothner + +LICENSE + +GPL. -- cgit v1.2.3