Re: syntax for hashes with variable in name

Your immediate problem is that perl interprets your %{ as a hash slice (see http://docstore.mik.ua/orelly/perl/learn/ch05_05.htm for a small example)

Your larger problem is that you want to use a technique that is a relict from perl4 days and only (if at all) suitable for quick hacks

Instead of using

my %{"platform_$site"};
${"platform_$site"}{"thingy"}= 5;
foreach my $x ( keys %{"platform_$site"}) {
  ...
[download]

use multidimensional hashes

my %platform;
$platform{$site}{"thingy"}= 5;
foreach my $x ( keys %{$platform{$site}}) {
  ...
[download]

You can use the same technique for your arrays as well, i.e. use a so called HashOfArrays:

push @{$platform{$site}}, 1,2;
$platform{$site}[5]= 5;
foreach my $x ( @{$platform{$site}}) {
  ..
[download]

PS: I also notice you don't use 'use warnings;' and 'use strict;' at the beginning of your script. It is highly advisable to include those two lines. Avoids many bug finding sessions later.

Comment on Re: syntax for hashes with variable in name Select or Download Code

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Re^2: syntax for hashes with variable in name by ikegami (Patriarch) on Nov 22, 2010 at 17:18 UTC
Hash (and array) slices always start with `@`. No slices start with `%`. `my %{"$name"};` [download] is the same as `my %{$name}` [download] which is the same as `my %$name; # Symbolic dereference` [download] which no more works than `my %$ref; # Generic deference` [download]	[reply] [d/l] [select]
Re^2: syntax for hashes with variable in name by ambrus (Abbot) on Nov 22, 2010 at 13:55 UTC
Your immediate problem is that perl interprets your %{ as a hash slice Is this for real?	[reply]
Re^3: syntax for hashes with variable in name by Tux (Canon) on Nov 22, 2010 at 16:46 UTC
is it? Let's rule out the fact that this deals with symbolic references, strict tells us ... `use strict; use warnings; { no strict "refs"; my $site = "foo"; my @{"platforms_$site"} = qw( foo bar ); my %{"platforms_$site"} = map { $_ => 1 } @{"platforms_$site"}; } => Can't declare array dereference in "my" at xx.pl line 8, near "} =" Execution of xx.pl aborted due to compilation errors.` [download] The difference is in the assignment part. You cannot use my there. When you drop those, you get: `use strict; use warnings; { no strict "refs"; my $site = "foo"; @{"platforms_$site"} = qw( foo bar ); %{"platforms_$site"} = map { $_ => 1 } @{"platforms_$site"}; }` [download] Which is still bad coding style, but this works. Enjoy, Have FUN! H.Merijn	[reply] [d/l] [select]
Re^3: syntax for hashes with variable in name by jethro (Monsignor) on Nov 22, 2010 at 16:02 UTC
It was the best explanation I could find at the moment. But I didn't check with deparse or something.	[reply]
Re^2: syntax for hashes with variable in name by equick (Acolyte) on Nov 22, 2010 at 13:06 UTC
Thanks for your reply. Yes usually I include strict, but I had just taken an extract of an old script I'm patching to work on that particular function. I also agree multidimensional arrays are probably the way to go, but if possible I'd rather keep the current variables as they are used throughout the other script.	[reply]