setting enviornment variables for parent process

Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

I'm trying write a script that can automatically set the display variable on an AIX server to run X applications over telnet, that can be ran from a users .cshrc file.

#!/usr/bin/perl -w
# /usr/local/bin/gethost.pl

# Find out where I'm calling from
open(WHOPROC, "who -m|"); # open who for reading
    $whoami = <WHOPROC>;
close (WHOPROC);

# print "$whoami";

($name,$port,$month,$day,$time,$host) = 
   split(/\s+/, $whoami);
   chop $host;
       $grab = substr($host, 1,);
#print "$grab\n";   

# Now set the display variable
$display = $grab . ':0.0';
# print "$display\n";

system "sh export DISPLAY='$display'";
[download]

Is there a way to make perl set the variable for the parent telnet session?

Comment on setting enviornment variables for parent process Download Code

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Re: setting enviornment variables for parent process by chromatic (Archbishop) on Feb 09, 2000 at 23:38 UTC
The system call actually forks a child process, runs exec on the process, waits for the process to exit, then returns. So what you're doing is spawning a new process and setting an environment variable in that process. Then the process exits, the environment variable is lost, and you're left scratching your head. (Just thought you might like to know why system wasn't appropriate here. :)	[reply]
RE: setting enviornment variables for parent process by setantae (Scribe) on Feb 09, 2000 at 07:58 UTC
Not really : perldoc -q environment You're doing a lot of unnecessary work here too, why not make use of the %ENV variable or Env module? setantae@eidosnet.co.uk\|setantae\|http://www.setantae.uklinux.net	[reply]
Re: setting enviornment variables for parent process by jamieamieamily (Initiate) on Feb 09, 2000 at 17:58 UTC
If this is to be run from a .cshrc then will the perl script also be executing any X applications? If so then setting the DISPLAY environment variable within the script is fine: `$ENV{DISPLAY}="$grab:0.0";` [download] Otherwise why use a perl script to export the value of $DISPLAY?	[reply] [d/l]
RE: Re: setting enviornment variables for parent process by Anonymous Monk on Feb 09, 2000 at 21:03 UTC
Mainly I'm just trying to learn perl as I have no programming experience at all. Also I was just trying to figure out a way so that users wouldn't have to type setenv DISPLAY 'theirhost:0.0' everytime they telnetted into the server. I tried ssh which works great as far as that respect but for really intesive X applications like Arcview and Arcinfo the encryption causes some major lag and hangups when moving or resizing windows.	[reply]
RE: RE: Re: setting enviornment variables for parent process by Anonymous Monk on Feb 10, 2000 at 04:20 UTC
I suspect the encryption can be disabled for ssh. Consider doing this on an as-needed basis.	[reply]