[Groff] SGR escape sequences as tty default: A faux pas.

[P. Alejandro Lopez-Valencia]

Well... This seems like a useless rant but I didn't have the chance to 
exercise groff current tty output capabilities with the new SGR escape 
sequences before. I have  done it under cygwin using the plain old win32 
console. And what I found I didn't like.

The release version (1.17.2) works find with the tty because it uses old 
no-nonsense escape codes. But groff-current *DOES NOT*. Why? Because it has 
defaulted to use SGR sequences in tty output. And *it doesn't work* under 
Cygwin.

It is a great idea if you are in Linux or FreeBSD, or if one is used to 
live in the bleeding edge and compile the latest xterm or eterm to play 
with in the proprietary OS he/she uses.

I am not sure that SGR sequences work in either IRIX or HP-UX. Why do I 
mention these two unix vendors in particular? Because none of the two has a 
bundled n/troff implementation and to have it you have to pay real money at 
real ATT Documenter's Workbench license prices (US$ 3000+  if still can get 
it). Therefore, those of us who have, or have had, the need to install a 
troff in those operating systems have always resorted to using groff. As 
well, I am not sure at all that you can use SGR escape sequences under 
Solaris' dtterm (the only color terminal that work in Solaris). 
Unfortunately, I cannot test this theory in either IRIX nor HP-UX and don't 
access to a Solaris for a couple of weeks more.

Therefore, my opinion is that groff should return to the previous behavior, 
and have SGR as an autoconf option, or as a runtime option flag for the 
grotty driver set up in grotty's DESC file or whatever. Else, it is quite 
possible that all people who are not using bleeding edge open source 
UNIX-like operating systems (many people still pay thousands of dollars for 
their production and time-sharing teaching machines, you know).

Else, many people will see this if trying to use groff's tty backend:


GCC(1)                      GNU Tools                      GCC(1)

ESC[1mNAMEESC[0m
       gcc, g++ - GNU project C and C++ Compiler (gcc-2.95)

ESC[1mSYNOPSISESC[0m
       ESC[1mgcc ESC[22m[ ESC[4moptionESC[24m | ESC[4mfilenameESC[24m ]...
       ESC[1mg++ ESC[22m[ ESC[4moptionESC[24m | ESC[4mfilenameESC[24m ]...

ESC[1mWARNINGESC[0m
       The  information  in  this man page is an extract from the
       full documentation of the GNU C compiler, and  is  limited
       to the meaning of the options.

NO underlines, NO bold, nothing more than screen garbage.


--
Alejandro López-Valencia
http://dradul.tripod.com/
[...] every cultured man is a theologian, and to be so
faith isn't needed. (J.L. Borges)