in reply to Re^5: replicating the command 'unset LIBPATH' in perl
in thread replicating the command 'unset LIBPATH' in perl

That can be simplified to: 
BEGIN {
    if (exists $ENV{LIBPATH}) {
        delete $ENV{LIBPATH};
        exec $^X, __FILE__, @ARGV;
    }
}

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Re^7: replicating the command 'unset LIBPATH' in perl
by viffer (Beadle) on May 19, 2010 at 02:07 UTC
    Thanks gents - I now feel like the beginner I am!

    But....what is __FILE__?

[reply]
      Its not a secret :) __FILE__ site:perldoc.perl.org The special literals __FILE__, __LINE__, and __PACKAGE__ represent the current filename, line number, and package name at that point in your program.
      $ perl -e"die __FILE__"
-e at -e line 1.

$ echo die __FILE__ > thefileis

$ perl -e"die __FILE__"
-e at -e line 1.

$ echo die __FILE__ > thefileis

$ perl thefileis
thefileis at thefileis line 1.

$ perl D:\thefileis
D:\thefileis at D:\thefileis line 1.

$

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[reply]
[d/l]
        OK - so __FILE__ is the name of my script, but I will admit to not understanding what you're trying to do with it.

        When I run your version of the BEGIN code, I get 

        Use of uninitialized value in string eq at /apps/bin/blah/reconcile_wi
+thdotsh.pl line 68.
        main::BEGIN() called at /apps/bin/blah/reconcile_withdotsh.pl 
+line 73
        eval {...} called at /apps/bin/blah/reconcile_withdotsh.pl lin
+e 73

        [download]
        where lines 68 and 73 are: 
        67 BEGIN {
68    unless( $ENV{ +__FILE__ } eq __FILE__ ){
69        delete $ENV{LIBPATH};     
70        $ENV{ +__FILE__ } = __FILE__;
71        exec $^X, __FILE__, @ARGV; # relaunch without LIBPATH
72    }
73}

        [download]
        It isn't __FILE__ that is the uninitialized value (as I put a print command in), so presumably its the "$ENV{ +__FILE__ }" but I can't manage to print that to check - and being in a BEGIN statement I can't step through it in debug.

        Also, in both versions the script just ends (as opposed to terminating with an error).

        Maybe I should be a heretic and go back to using COBOL on a mainframe! Do any still exist?

        Cheers

        Kev

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