topic Re: Toggling xterm logging in Operating System - HP-UX

Toggling xterm logging

Raj Kotaru — Mon, 10 Nov 2003 13:14:30 GMT

Hello All,

I have an application that is running in, and writes to the stdout of an xterm window. I need to create a log of the output from the application.

I am aware that after the application has started, one can enable or disable logging via a mouse click by selecting or deselecting the "log to file" option in the pop down menu.

However, this requires one to have access to the xterm window itself. If I am diailing in via a modem into the machine where my application is already running in an xterm window, is there anay way that I can send a message from the command line that essentially does the same thing as toggling the "log to file" menu item?

I am running HP-UX B.10.20 on a 9000/820 series machine.

Thanks
Raj

Re: Toggling xterm logging

Graham Cameron_1 — Tue, 11 Nov 2003 05:30:26 GMT

Are you really running xterm, or is it some other emulator (eg hpterm, dtterm).

I ask because I don't think xterm has logging capability (not on my machine and not in the man page), whereas hpterm and dtterm do.

If hpterm or dtterm, why not just start up logging at invocation time (using "-l -lf logfile") and leave it on ?

-- Graham

Re: Toggling xterm logging

Elmar P. Kolkman — Tue, 11 Nov 2003 06:27:19 GMT

I have seen ways in the past, but if they still work, it is a security issue...

But it depends on what you want. A way that works is using xwd... You can dump the contents of the hpterm at the time you want the contents. But to get info over a period of time, this will not work.

Re: Toggling xterm logging

Mark Grant — Tue, 11 Nov 2003 06:30:56 GMT

well, specifically in the case of a dtterm, it has the default action for all signals. The default action is to terminate so I guess there isn't much you can do apart from the suggestions above.

Re: Toggling xterm logging

Rick Beldin — Tue, 11 Nov 2003 09:09:15 GMT

xterm logging has been disabled by and large by most vendors.

A better solution would be to modify the command that is running in the xterm window to use the tee command and log all of the application output to a file that you can examine remotely.
You might have to dig around through the apps startup scripts to achieve this. Another optio n might be to modify the application script to use typescript.

Re: Toggling xterm logging

Raj Kotaru — Tue, 11 Nov 2003 11:24:43 GMT

Thanks to all those who responded. I did finally find a way to do this.

I used the -lf option to xterm to specify a logfile, except that instead of specifying an actual file name, I specified the endpoint of a pipeline. This can be a shell script to which the output from the xterm window would be piped as input. I wrote the script in the korn shell to utlize the ability to handle signals sent to the script. I used the SIGUSR1 signal to specify to the shell script that its input needs to be logged, and the SIGUSR2 signal to specify that its input no longer needs to be logged.

To send the signals, I used the "kill" command. For example, "kill -SIGUSR1 pid", where pid is the process id of my korn shell script. This seems to work.

Thanks
Raj