Debugger goodies rendered worthless

IvorW combobulus at xemaps.com
Thu Jun 21 10:36:43 BST 2007



> -----Original Message-----
> From: David Alban [mailto:extasia at extasia.org]
> Sent: 20 June 2007 17:45
> To: London.pm Perl M[ou]ngers
> Subject: Debugger goodies rendered worthless
> 
> 
> 
> Greetings,
> 
> As you may know, the ability to start a perl debugger command with a
> pipe symbol, so that it pages the output, can be a very handy thing.
> Both to actually page the output, and, in the case of using less(1) as
> your pager, to be able easily to save the output to a file while
> debugging.
> 
> I'm debugging on a machine in which many things that have worked for
> me on other machines don't seem to work.  Prepending the pipe symbol
> to debugger commands doesn't page the output.  The terminal settings
> are messed up.  For instance, the stty settings for erase, kill,
> werase, lnext aren't set.  (I tried setting them in the target user's
> .bash_profile, to no avail.)  In fact, in the debugger, this works:
> 
>  !! ls
> 
> But I get:
> 
>  DB<10> !!stty
> stty: standard input: Invalid argument
> (Command exited 1)
> 
> wtf?
> 
> Because the stty erase, werase, and kill characters aren't set (or, at
> least, because I can't shell out to execute stty, I can't determine
> what they are), I have to type each debugger command perfectly, or I'm
> wasting a lot of time.
> 
> Any suggestions?

Do you have Term::ReadLine::Gnu and/or Term::ReadLine::Perl installed? These might help.

Secondly, can you please supply the output of the O command to the debugger. This will provide useful information to diagnose your settings.
> 
> --------------------------------------------------------------
> -----------------------------------
> Since I wrote the above text, I figured, maybe it's because what I'm
> doing is running a perl program on host A which is ssh'ing to host B,
> sudo'ing another perl program as root.  I think that somehow, going
> over the network and/or going through ssh is rendering the helpful
> features inoperative.
> 
I'm not convinced. This looks like a tty issue on the box running the script to me.



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