SPUG: each() on hashref giving INFINITE LOOP!

[Bradley E. Young]

Tim,

Looks like the last chunk is giving you fits because it doesn't iterate over
the hash.  You are setting $key and $value to the first two elements of
%$hash every loop through.

I think that you might have meant to do this:

	$i=0;	# sense and break out of infinite loop!
 	while ( ($key,$value) = each %$hashref ) {
 		print "$key -> $value\n";
 		$i++; # break out of infinite loop
 		$i > 3  and  die "\tInfinite Loop Terminated!\n";
 	}
 	return 1;

Notice the addition of each().

Brad
> -----Original Message-----
> From: owner-spug-list at pm.org [mailto:owner-spug-list at pm.org]On Behalf Of
> Tim Maher/CONSULTIX
> Sent: Friday, January 21, 2000 3:33 PM
> To: spug-list at pm.org
> Subject: SPUG: each() on hashref giving INFINITE LOOP!
>
>
> The following program, a simple demo for passing and using a hash-ref, is
> getting an infinite loop when using while(each) in the sub, but not
> when using foreach there!  Can anybody shed some light on this?
>
> -Tim
>
> $ animal2title
> Here is the hash:  Camel Programming Perl Llama Learning Perl
> These are the keys:  Camel Llama
> Camel -> Programming Perl
> Llama -> Learning Perl
>
> (while loop starts now)
> Camel -> Programming Perl
> Camel -> Programming Perl
> Camel -> Programming Perl
> Camel -> Programming Perl
> 	Infinite Loop Terminated!
>
> #! /usr/bin/perl -w
> # animal2title
>
> use strict;
> #sub print_hash;	# not complaining this time, for some reason!
>
> $main::DEBUG=1;
> my $h_ref = { } ;		# create reference to empty hash
>
> # Load animals and their corresponding O'Reilly Perl-book titles
> $h_ref->{Camel} =  'Programming Perl';
> $h_ref->{Llama} =  'Learning Perl';
>
> if ($main::DEBUG) {local $,=' '; print "Here is the hash: ",
> %$h_ref, "\n"; }
>
> print_hash ( $h_ref );	# call sub that takes hash ref
>
> sub print_hash {
> 	my ($i, $key, $value, $hashref);
>
> 	if (ref ($hashref=shift) ne 'HASH')  {
> 		warn ((caller 0)[3],	# provides sub's name
> 			"(): argument \"$hashref\" not hash ref\n");
> 		return 0;
> 	}
> 	if ($main::DEBUG) {
> 		local $,=' ';
> 		print "These are the keys: ", keys %$hashref, "\n";
> 	}
>
> 	foreach ( keys %$hashref ) {
> 		print "$_ -> $$hashref{$_}\n";
> 	}
> 	print "\n";
>
> 	$i=0;	# sense and break out of infinite loop!
> 	while ( ($key,$value) = %$hashref ) {
> 		print "$key -> $value\n";
> 		$i++; # break out of infinite loop
> 		$i > 3  and  die "\tInfinite Loop Terminated!\n";
> 	}
> 	return 1;
> }
>
> TIA, as usual,
>
> *========================================================================*
> | Tim Maher, PhD  Consultix &              (206) 781-UNIX/8649           |
> |  Pacific Software Gurus, Inc             Email: tim at consultix-inc.com  |
> |  UNIX/Linux & Perl Training              http://www.consultix-inc.com  |
> | 2/22: UNIX  2/28: Perl Modules  2/29: Int. Perl  3/3: Pattern Matching |
> *========================================================================*
>
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