in reply to system/exec and %ENV

Well, if you run exec "date" usually nothing following that call will be executed. The normal behavior of exec is not to return since you've replaced your program with the one you've exec-ed.

Don't know what's happening with system(). How about showing us a script which triggers the problem?

Also, note that calling external programs will not affect %ENV. Even if the external program modifies an environment variable, it's only modifying it's own local copy.

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Re^2: system/exec and %ENV
by eosbuddy (Scribe) on Jul 16, 2008 at 05:53 UTC
    Thanks a ton for that quick reply... Indeed, as you mentioned, exec was the culprit (I am a n00b ;-) ). The code fragment, nonetheless is here (have commented out the exec) - Thanks again for your help and reply on the dot.: 
    #!/usr/bin/perl

system "date";



#system 'ls -l $HOME |awk \'{ print $8 }\'';



#exec "date";



#print "$ENV{'PATH'}\n";

#$ENV{'PATH'} = "/home/athampan:$ENV{'PATH'}";

#print "$ENV{'PATH'}\n";





foreach $var (sort keys %ENV)  {

     print "$var => $ENV{$var}\n"

}

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[d/l]

      Had you used warnings, you'd have got an error message:

      use strict;
use warnings;

exec 'date';
print "still alive\n";

      [download]
      Statement unlikely to be reached at - line 5.
    (Maybe you meant system() when you said exec()?)
Wed Jul 16 08:36:05 CEST 2008

      [download]

      --
      David Serrano

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      Works (as expected) for me, linux and Windows: 
      Tue Jul 15 22:56:32 PDT 2008
CDPATH => .:/home/ikegami:/home/ikegami/www
EDITOR => pico -w -z
...

      [download]
      The current date is: 2008/07/16
Enter the new date: (yy-mm-dd)
ALLUSERSPROFILE => C:\Documents and Settings\All Users
APPDATA => C:\Documents and Settings\ikegami\Application Data
CLIENTNAME => Console
...

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        HI Ikegami and pc88mxer - thanks much for both of your efforts, this issue is sorted out quickly through your replies. Regards to all.
[reply]

      Unrelated to your original question, but calling out to a shell to get a listing of files is very Rube-Goldberg-ian. See opendir and readdir (and possibly stat if you're interested in the file properties ls -l shows).

      The cake is a lie.
      The cake is a lie.
      The cake is a lie.

[reply]
        Thanks Hue-Bond and Fletch for your insights. As I mentioned, I am a n00b and "learning perl ... randal et al" and was trying out the commands in the book. As is characteristic n00bishness, I hadn't read the material immediately following the exec treatment (I assumed it to function much like the php directive). Thanks all for the kind help (and not yelling at me to go read the book :-) )
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[d/l]

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