How do you restore the display after 'cat'-ing a file that distorts it?
Tony Curtis
> I have several Unix boxes running HP-UX 10.20, Sun Solaris 2.6, and
> Redhat Linux 6.0 in various configurations. Sometimes my display will
> distort if I accidently 'cat' a bad file, or a binary file, or a print
> output file that has control chracters in it. By "distort" I mean the
> characters on my screen will be unreadable
> garbage. ...
> Exceed program to connect to my boxes using X-terminal sessions, but I
You need to tell the xterm to reset. You can do
this through the Ctrl-Middle-mouse chord to get the
menu, choose "Full Reset".
I presume this is the same as sending the hard reset
string as defined for xterm in the term{cap,info}
file (but i'm on a you-know-what laptop and don't
have xterm to test).
hth
tony
Lokesh Setia
Close your eyes, pray to god, and type this:
/bin/echo "\033c"
or
echo <Ctrl-V><Esc>c
and hopefully you'll see your prompt again :).
Regards,
Lokesh.
>>>>> "Craig" == Craig Bisher <cbi...@spamblock.yahoo.com> writes:
Craig> I have several Unix boxes running HP-UX 10.20, Sun Solaris
Craig> 2.6, and Redhat Linux 6.0 in various
Craig> configurations. Sometimes my display will distort if I
Craig> accidently 'cat' a bad file, or a binary file, or a print
Craig> output file that has control chracters in it. By "distort"
Craig> I mean the characters on my screen will be unreadable
Craig> garbage. The commands that I type in continue to operate
Craig> properly, but they are not displayed in the correct
Craig> format. Is there a command to restore the terminal screen
Craig> to the proper settings when this occurs? I am using the
Craig> Hummingbird Exceed program to connect to my boxes using
Craig> X-terminal sessions, but I have seen this problem happen at
Craig> the console screen as well. Usually, if I log out of the
Craig> box and right back in, the display is restored. I would
Craig> much rather run a script or command that would do this
Craig> immediately. Any help or direction to a man page or
Craig> documentation would be appreciated.
Craig> -Craig
--
When we come back, I'll drop a line. (The Doors)
Jack Perdue
>
> I have several Unix boxes running HP-UX 10.20, Sun Solaris 2.6, and
>Redhat Linux 6.0 in various configurations. Sometimes my display will
>distort if I accidently 'cat' a bad file, or a binary file, or a print
>output file that has control chracters in it. By "distort" I mean the
>characters on my screen will be unreadable garbage. The commands that
>I type in continue to operate properly, but they are not displayed in
>the correct format. Is there a command to restore the terminal screen
>to the proper settings when this occurs? I am using the Hummingbird
>Exceed program to connect to my boxes using X-terminal sessions, but I
>have seen this problem happen at the console screen as well. Usually,
>if I log out of the box and right back in, the display is restored. I
>would much rather run a script or command that would do this
>immediately. Any help or direction to a man page or documentation
>would be appreciated.
You can try "reset"... might help.
jack
j-pe...@tamu.edu
Colin Smith
>
> I have several Unix boxes running HP-UX 10.20, Sun Solaris 2.6, and
> Redhat Linux 6.0 in various configurations. Sometimes my display will
> distort if I accidently 'cat' a bad file, or a binary file, or a print
> output file that has control chracters in it. By "distort" I mean the
> characters on my screen will be unreadable garbage. The commands that
[snip]
Try "tput reset".
--
Colin Smith
Tony Curtis
> <lok...@sh.bel.alcatel.be> wrote:
>
> >/bin/echo "\033c"
> >echo <Ctrl-V><Esc>c
>
> Both of these methods worked for me. Thanks. Now, the next time my
> screen freaks out and I use these key combinations to reset it,
> someone will ask me "what does that do?". How can I explain what is
> happening when I do this?
It's sending the "reset" string to the terminal.
Which is presumably what the Ctrl-Mouse thing does
too. "man terminfo" for more info on terminal
control.
hth
tony
Mike Stroyan
| Both of these methods worked for me. Thanks. Now, the next time my
|screen freaks out and I use these key combinations to reset it,
|someone will ask me "what does that do?". How can I explain what is
|happening when I do this?
You probably sent a ctrl-N to the terminal, choosing the alternate
font. The hard reset would switch back to the default font. You can
also use ctrl-O character to change back, like-
echo ctrl-O
Some shells will echo ctrl-O back as "^O" as you type it. The echo
should take care of that.
--
Mike Stroyan, mike_s...@fc.hp.com
Lokesh Setia
Craig Bisher <cbi...@spamblock.yahoo.com> writes:
> <lok...@sh.bel.alcatel.be> wrote:
>
> >/bin/echo "\033c"
> >echo <Ctrl-V><Esc>c
>
> Both of these methods worked for me. Thanks. Now, the next time my
> screen freaks out and I use these key combinations to reset it,
> someone will ask me "what does that do?". How can I explain what is
> happening when I do this?
A terminal (physical or emulated) understands "Control signals". These
control signals are usually implemented in terms of Escape
Sequences. When you write these Escape sequences to a terminal, they
are not written to the screen, but the terminal driver takes special
actions for these sequences. In fact, we use most of these sequences
everyday, but don't notice it. For e.g., when you use vi, and say go
one line up, the whole screen is not written (it would be too slow),
but a special "escape sequence" is sent which asks the driver to move
the cursor to the specific location.
Here, "Esc c" is the sequence to reset a terminal. It is fairly
portable among different terminals (vt100, xterm...). To write the
"esc" character, we need to prefix it with <Ctrl-V>, so that the <esc>
character is taken literally.
So echo <Ctrl-V><Esc>c works.
The octal code for Esc is 033, so in principle echo "\033c" also
works, but some inbuilt echo programs (like in bash) do not honour the
backslashed things like \033 unless you give the option -e.
So, I wrote /bin/echo "\033c" instead of only echo "\033c" so that the
binary in /bin will be executed instead of the shell built-in.
Regards,
Lokesh.
Richard S. Shuford
>
> Sometimes my display will distort if I accidently 'cat' a bad file,
> or a binary file, or a print output file that has control chracters
> Is there a command to restore the terminal screen to the proper
> settings when this occurs?
and Lokesh Setia offered help:
:
: ..."Esc c" is the sequence to reset a terminal. It is fairly
: portable among different terminals (vt100, xterm...)
The Escape c control sequence is the ANSI-X3.64/ISO-DP6429
"RIS" or Hard Terminal Reset. If this 2-octet sequence is
executed on a terminal or emulator that follows the standard
(which the xterm emulation does), then the effect is to reload
all "power-on" default terminal settings. (Or to restore NVR/
Non-Volatile RAM settings, if the terminal has those, as on a
DEC VT420.)
If you want a less drastic type of reset, you could "cat" a
short file to your screen containing controls that reset only
the most frequently damaged terminal settings (including the
alternate character set). I constructed such a file a few
years ago; you can get it from:
http://www.cs.utk.edu/~shuford/terminal/cls.uue
This is part of a collection of information on video terminals:
http://www.cs.utk.edu/~shuford/terminal_index.html
...Richard S. Shuford
--
Stratus Computer, Maynard, Massachusetts http://www.stratus.com/
Duplex-hardware fault-tolerant computer systems running VOS or HP-UX.
This message does not contain the official opinion of Stratus.
Francois Laupretre
It should reset a 'normal' behaviour. And it works with any type of terminal
(xterm, console, ...). It is described in the 'stty' man page.
Bernard Chandler
> Craig Bisher <cbi...@spamblock.yahoo.com> wrote:
> >and Lokesh Setia offered help:
> :
> : ..."Esc c" is the sequence to reset a terminal. It is fairly
> : portable among different terminals (vt100, xterm...)
>
> The Escape c control sequence is the ANSI-X3.64/ISO-DP6429
> "RIS" or Hard Terminal Reset. If this 2-octet sequence is
> executed on a terminal or emulator that follows the standard
> (which the xterm emulation does), then the effect is to reload
> all "power-on" default terminal settings. (Or to restore NVR/
> Non-Volatile RAM settings, if the terminal has those, as on a
> DEC VT420.)
>
> If you want a less drastic type of reset, you could "cat" a
> short file to your screen containing controls that reset only
> the most frequently damaged terminal settings (including the
> alternate character set). I constructed such a file a few
> years ago; you can get it from:
>
> http://www.cs.utk.edu/~shuford/terminal/cls.uue
>
> This is part of a collection of information on video terminals:
>
> http://www.cs.utk.edu/~shuford/terminal_index.html
>
> ...Richard S. Shuford
> --
> Stratus Computer, Maynard, Massachusetts http://www.stratus.com/
> Duplex-hardware fault-tolerant computer systems running VOS or HP-UX.
> This message does not contain the official opinion of Stratus.
I find i get results with
stty sane and control j