Why do I get a syntax error when I try to print a nested hash that has keys containing colons? - perl

Question

I'm trying to print an element of a nested data structure:
$VAR1 = {
'SOAP:Body' => {
'ns1:MT_DF_AssetMaster_Response' => {
'SUBNUMBER' => {},
'ASSETCREATED' => {
'SUBNUMBER' => {},
'ASSET' => {},
'COMPANYCODE' => {}
},
'RETURN' => {
'PARAMETER' => 'timedependentdata',
'MESSAGE_V2' => {},
'ID' => 'BAPI1022',
'MESSAGE_V1' => 'HW5790',
'ROW' => '0',
'TYPE' => 'E',
'FIELD' => 'plate_no',
'LOG_NO' => {},
'MESSAGE_V3' => {},
'SYSTEM' => 'xxx',
'MESSAGE' => 'Invalid date transferred for field xxx:',
'MESSAGE_V4' => {},
'NUMBER' => '041',
'LOG_MSG_NO' => '000000'
},
'xmlns:ns1' => 'urn:ariba.com:xi:OnDemand:Asset',
'ASSET' => {},
'COMPANYCODE' => {}
}
},
'xmlns:SOAP' => 'http://schemas.xmlsoap.org/soap/envelope/',
'SOAP:Header' => {}
};
print "$data->{SOAP:Body}->{ns1:MT_DF_AssetMaster_Response}->{ASSETCREATED}=>{ASSET}\n";
But I get a syntax error:
syntax error at ./asset_creation.pl line 85, near "{SOAP:"
How can I fix this?

Answer 1

You must write something like this
my $asset = $data->{'SOAP:Body'}{'ns1:MT_DF_AssetMaster_Response'}{ASSETCREATED}{ASSET};
print %$asset ? "Asset is NOT empty\n" : "Asset is empty\n";

Answer 2

The following are the syntaxes for a hash lookup via reference:
REF->{IDENTIFIER}
REF->{EXPR}
ns1:MT_DF_AssetMaster_Response is neither a valid identifier, nor a valid expression. Replace
->{ns1:MT_DF_AssetMaster_Response}
with
->{'ns1:MT_DF_AssetMaster_Response'}

Answer 3

Perl allows an expression inside the subscripts for an array or a hash. For instance, a variable:
$array[ $i ]
Or the result of an addition:
$array[ $i + $offset ]
Or something
$array[ cos( $i ) ]
It's the same with a hash:
$hash{ $key }
The dot is still the string concatenation operator:
$hash{ $key . $prefix }
It's harder to spot when you have barewords smooshed together:
$hash{first.last}
And in this case, the : is still part of the namespace separator. Perl thinks you aren't done with this expression in the braces so it complains:
$hash{ SOAP:Body } # !!! Error

Answer 4

SOAP:Body must be quoted: The : may not be used without quoting as hash key:
print $data->{'SOAP:Body'}->{'ns1:MT_DF_AssetMaster_Response'}
You should also remove the " " around the variable name in your print statement. The hashref-dereferencing doesn't work otherwise. Your output would be something like
HASH(0x123456)->{SOAP:Body}->{ns1:MT_DF_AssetMaster_Response}
...but you may still have another error if line 85 isn't the print command.