in reply to How to remove the actual glob from a glob reference

now I have two typeglobs pointing to same address

No, you have two references pointing to the same (ie a single) typeglob. undef $a causes one of the references to the typeglob to be freed (the typeglob itsself is not yet freed, since $b still contains a reference to it).

If in addition you do undef $b, then the typeglob will be freed. But it's not clear to me what you are actually trying to achieve.

Dave.

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Re^2: How to remove the actual glob from a glob reference
by targetsmart (Curate) on Oct 06, 2008 at 07:17 UTC
    Thanks for your comments and yes I got your point, I know that undef $b will do, But I need to delete $b using $a, The typeglob itself need to be freed via $a without actually using $b. Have you got it now?.
[reply]
      Thanks for your comments and yes I got your point, I know that undef $b will do, But I need to delete $b using $a, The typeglob itself need to be freed via $a without actually using $b. Have you got it now?.
      "delete $b using $a" doesn't make much sense. Do you want to delete the reference $b (leaving the typeglob it refers to unchanged), or do you want to delete the typeglob itself?

      You cant delete the typeglob while a reference to it still exists (from $a or $b). You can however make it undefined, (freeing up any IO handles etc attached to it) with the following: 

      undef *$a

      [download]

      Dave.

[reply]
[d/l]
        You cant delete the typeglob while a reference to it still exists (fro
+m $a or $b). You can however make it undefined, (freeing up any IO ha
+ndles etc attached to it) with the following:

        [download]
        Thanks for giving me a solution, I have understood, but I have one more question, Let us consider the below code, 
        open $a, "/etc/passwd" or die "can't  open /etc/passwd: $!\n";
{
        local $/ = undef;
        $userdetails = <$a>;
        print ">>",$userdetails,"<<\n";
}
close($a); # this closes the filehandle
print "A>",$a ,"<\n";  # this prints a glob
# .... (assume that some lines of code lies here)
# ..

#########################################################
# in some other part of the program, How do I check whether
# the filehandle associated with the handle is still open?
# I have done it this way, if(defined fileno($a)),
# because fileno(filehandle) will return undef if there is
# no filehandle associated with it.
# Is any other ways exist to check the above problem?.
#########################################################

        [download]
[reply]
[d/l]
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