Red Hat Bugzilla – Bug 75099
character set line drawing G0 G1 G2 G3
Last modified: 2015-01-07 19:00:48 EST
From Bugzilla Helper:
User-Agent: Mozilla/4.0 (compatible; MSIE 5.01; MSNIA; Windows 98; MSNIA)
Description of problem:
The line drawing character sets are not available under RedHat 8.0.
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1. From command line, echo desire line drawing ESC mode and character:
2. # echo -e "ESC[12mMMMMMMM ESC[10m"
# echo -e "^Nqqqqqqq^O"
Actual Results: Line drawing characters are not displayed.
Expected Results: Either command should set character mode and echo
appropriate line drawing character.
It apears that the termcap entries are the same for linux| console| and xterm|
as previous versions of RedHat. I'm not sure exactly where the problem is,
whether it's termcap or somewhere else.
This capability should be available on any type of installation to support
third party software.
I believe it has to do with RH 8.0's new default unicode font system.
This also causes display problems in third-party software BASIS Pro5
(www.basis.com), a "Business BASIC" interpreter which uses termcap. Pro5 works
fine in RH 7.1, but in RH 8.0 it no longer displays line drawing characters and
no longer allows for characters to be bold (set to be brighter than other
I have found a few workarounds...
If you enter the following:
# echo -e \\033%@
it will set the current console screen to use the default character set (ISO
646/ISO 8859-1), allowing line drawing characters to again be displayed
The problem with character brightness seems more complicated. If you enter
the following command:
it sets the linux console to use the default font without unicode, which allows
brightness to work again (even when doing a 'man').
The problem is that when you log into another console screen, it does its
default 'setfont <something>' when logging in, which resets the font across all
console screens, which has the effect of resetting the font for the first
screen on which you entered the 'setfont' workaround before -- this can cause
some unreadable characters to appear when switching back to the first screen.
To illustrate, try the following:
1) Log in to tty1 as 'root' and leave tty2 with a "login" prompt.
2) # man echo
3) Notice that the text in the 'man' page is all gray.
4) Exit 'man'.
5) # setfont
6) # man echo
7) Now see that the 'man' page is properly displayed (gray w/ white highlights).
8) Then with 'man' still running on tty1, switch to tty2 and login as 'root'.
9) Now go back to tty1 and see that the brightness has disappeared and some
characters are unreadable, but when you scroll the man page down (to put the
unreadable characters off-screen) and then back up again, it fixes those bad
characters -- although the brightess is still gone.
10) Now go to tty2 and enter 'setfont' on that screen.
11) Finally, go back to tty1 and scroll the man page down and back up to see
the brightness return.
When combining these 2 work arounds:
# echo -e \\033%@
it causes everything in Pro5 to display properly -- line drawing characters and
brightness problems are both fixed.
But if not in Pro5 and using both these commands, then doing something from
the linux console shell (like a 'man echo') will cause the characters which are
highlighted on the 'man' page to be unreadable.
And even though these 2 commands temporarily fix display problems in Pro5,
because 'setfont' is used if you log into another console screen and come back
to the Pro5 screen: the brightness is lost for good, and other characters are
garbled until the screen is redrawn by whatever BASIC program is running.
I have not tried your example in Red Hat Linux 8.0
but it works fine in FEDORA CORE 4.
That is why I am not able to say where 'a possible bug' was.
I will close this 'issue': Fixed in current release.
Launch at the command prompt: nohup xterm &
Launch at the command prompt: export LANG=en_US
Launch at the command prompt: export TERM=xterm
Launch at the command prompt: tput smacs
Launch at the command prompt: qqqqqqqqq
Launch at the command prompt: <Enter-key>
Launch at the command prompt: tput sgr0
NOTE: a) 'tput' reads terminfo-database (not /etc/termcap).
b) /etc/termcap should not be used
c) Launch at the command prompt (for more info):