I know why this is happening, however i can't for the life of me figure out how to prevent it.

I have a template file that contains items, like the following

<xml>
<file>$rec->{filename}</filename>
<ipv4>$rec->{IPAdress}</filename>
<something>$foo</something>
</xml>

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On this file I do the following operation, in order to expand those varaible and hashrefs

for my $line (@template){
     $line =~ s/(\$\w+->{\w+})/$1/eeg;
     $line =~ s/(\$\w+)/$1/eeg;
     $text .= $line;
}

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This technically works, however whenever $1 expands to a NULL value in the hashref (pulled from mysql). It errs with Use of uninitialized value in substitution iterator. I've tried a few things to get around it, neither worked, but i'm also unsure if either are techncially legal syntax. Those attempts are as follows

        for my $line (@cfile){
            $line =~ s/(\$\w+->{\w+})/$1||''/eeg;
            $line =~ s/(\$\w+)/$1||''/eeg;
            $text .= $line;
         }

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as well as

        for my $line (@cfile){
            $line =~ s/(\$\w+->{\w+})/defined $1 ? $1 : ''/eeg;
            $line =~ s/(\$\w+)/defined $1 ? $1 : ''/eeg;
            $text .= $line;
         }

[download]

I've seen one example in the Monastery, but it didn't resolve the issue. Any insight would be greatly appreciated.

In reply to Use of uninitialized value in substitution iterator in variable expansion by jaco

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