Perl Global symbol requires explicit package name

Question

I am trying to store my log messages in a hash depending upon message type as shown below: ``` #!/usr/bin/perl use strict; use warnings; my %log; opendir (DIR, '.') or die $!; while (my $file = readdir(DIR)) { # some code to select TAR filename in $1 if (-e $1.'.tar') { push(@{$log->{$1}}, $file); /* line 12 */ } else { $log{$1} = []; push(@{$log->{$1}}, $file); /* line 16 */ } ``` Now this code gives compilation error saying: ``` Global symbol "$log" requires explicit package name at at lines 12 & 16 ``` where I am actually trying to use the hash "%log". What can be a possible way to get rid of this error ? Why exactly is this happening ? I did see some explanation on context where people replied saying the variables were created in one context and were being referred in another but I feel this variable should be available inside while loop in this piece of code. This happens only when I have "use strict" and works fine otherwise. I have started with Perl so I do not fully understand…

Accepted Answer

```
my %log;
```

defines hash `%log`, but lines 12 and 16 don't use it. Instead, you're accessing the anonymous hash referenced by the scalar `$log` which you've never declared. You have two options.

You could continue to use an anonymous hash.

```
my $log = {};   # The creation of the hash ("{}") is currently being done
                # implicitly by "->". This is called autovivification.

... $log->{...} ...
```

This adds a bit of a extra complexity and an unnoticeable reduction in speed.

You could use use a hash directly.

```
my %log;

... $log{...} ...
```

Perl Global symbol requires explicit package name

Solution

Problem