CODEWITHSUNDEEP
perl
David Green
David Green

Reputation: 1234

Perl - Global symbol requires explicit package name

I am calling a perl subroutine

&ProcessInput($line, \%txcountershash, \%txhash);

I have this definition: 

sub ProcessInput() {    
my $word;
my $counterkey;   
my $line = $_[0];
my $countershash = $_[1];
my $outputhash = $_[2];  

# remove all the blanks from the line
$line =~ s/\s+//g;  

my ($port,$counter,$value,$datetime) = split('\|',$line,4);

my $counterdesc = $countershash{$counter};

the line that causes the problem is the last line. It says that global symbol %countershash requires explicit package name. I'm not sure why it's giving me the error. There aren't any problems otherwise, if I comment that line out the script runs. The hash is set up as an error code for a key and a description that is the value. I'm trying to get the value at a particular key in $countershash so I can add the error description to the output hash.

Upvotes: 1

Views: 1590

Answers (2)

Dave Cross
Dave Cross

Reputation: 69224

The code $counterhash{$counter} means "look up the key $counter in the hash %counterhash". You don't have a hash called %counterhash, you have a hash reference in a scalar variable called $counterhash. %counterhash and $counterhash are two completely different variables.

In order to look up an element in a hash reference, you need to use different syntax.

my $counterdesc = $countershash->{$counter};

Please don't use the $$countershash{$counter} syntax (previously) used in another answer. That will only confuse whoever needs to maintain your code in six months time (which might well be you).

Upvotes: 0

mkHun
mkHun

Reputation: 5927

The problem is dereferencing. you should dereference the hash inside the subroutine

my $counterdesc = $countershash->{$counter};

-> this is called arrow operator which is used to deference the array and hashes.

Upvotes: 1

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