Linux/st: Simple Terminal from SuckLess - st - A Git Server for Collaborative Work

Simple Terminal from SuckLess

Hiltjo Posthuma 818ec746f4 fix unicode glitch in DCS strings, patch by Tim Allen Reported on the mailinglist: " I discovered recently that if an application running inside st tries to send a DCS string, subsequent Unicode characters get messed up. For example, consider the following test-case: printf '\303\277\033P\033\\\303\277' ...where: - \303\277 is the UTF-8 encoding of U+00FF LATIN SMALL LETTER Y WITH DIAERESIS (ÿ). - \033P is ESC P, the token that begins a DCS string. - \033\\ is ESC \, a token that ends a DCS string. - \303\277 is the same ÿ character again. If I run the above command in a VTE-based terminal, or xterm, or QTerminal, or pterm (PuTTY), I get the output: ÿÿ ...which is to say, the empty DCS string is ignored. However, if I run that command inside st (as of commit `9ba7ecf`), I get: ÿÃ¿ ...where those last two characters are \303\277 interpreted as ISO8859-1 characters, instead of UTF-8. I spent some time tracing through the state machines in st.c, and so far as I can tell, this is how it works currently: - ESC P sets the "ESC_DCS" and "ESC_STR" flags, indicating that incoming bytes should be collected into the strescseq buffer, rather than being interpreted. - ESC \ sets the "ESC_STR_END" flag (when ESC is received), and then calls strhandle() (when \ is received) to interpret the collected bytes. - If the collected bytes begin with 'P' (i.e. if this was a DCS string) strhandle() sets the "ESC_DCS" flag again, confusing the state machine. If my understanding is correct, fixing the problem should be as easy as removing the line that sets ESC_DCS from strhandle(): diff --git a/st.c b/st.c index ef8abd5..b5b805a 100644 --- a/st.c +++ b/st.c @@ -1897,7 +1897,6 @@ strhandle(void) xsettitle(strescseq.args[0]); return; case 'P': /* DCS -- Device Control String / - term.mode \|= ESC_DCS; case '_': / APC -- Application Program Command / case '^': / PM -- Privacy Message */ return; I've tried the above patch and it fixes my problem, but I don't know if it introduces any others. "		4 years ago
FAQ	FAQ: fix single-buffer patch	4 years ago
LEGACY	LEGACY: typo.	12 years ago
LICENSE	LICENSE: fix a few years	6 years ago
Makefile	Makefile: fix dependencies on config.h	6 years ago
README	tic -s -> tic -sx (Treat unknown capabilities as user-defined.)	8 years ago
TODO	Remove old TODO entry.	9 years ago
arg.h	don't modify argv, use a counter	6 years ago
config.def.h	config.def.h: add an option allowwindowops, by default off (secure)	4 years ago
config.mk	bump version to 0.8.3	4 years ago
st.1	Add support for scroll(1)	4 years ago
st.c	fix unicode glitch in DCS strings, patch by Tim Allen	4 years ago
st.h	config.def.h: add an option allowwindowops, by default off (secure)	4 years ago
st.info	Partially add back in "support REP (repeat) escape sequence"	4 years ago
win.h	better Input Method Editor (IME) support	5 years ago
x.c	Call xsetcursor to set win.cursor in main	4 years ago

README

st - simple terminal
--------------------
st is a simple terminal emulator for X which sucks less.


Requirements
------------
In order to build st you need the Xlib header files.


Installation
------------
Edit config.mk to match your local setup (st is installed into
the /usr/local namespace by default).

Afterwards enter the following command to build and install st (if
necessary as root):

    make clean install


Running st
----------
If you did not install st with make clean install, you must compile
the st terminfo entry with the following command:

    tic -sx st.info

See the man page for additional details.

Credits
-------
Based on Aurélien APTEL <aurelien dot aptel at gmail dot com> bt source code.