pinnacle has asked for the wisdom of the Perl Monks concerning the following question:

When I run the below mentioned code I don't get anything on stdout, I don't understand why parXML function not parsing each file and outputting data, undermentioned code this is just a part of whole script. Also my script does not shows any syntax error,it runs through with no output,Please help thanks!!

I want to output specific rows from xml stored in multiple files

I have stored files in an array

@array = `ls file* | awk '{print \$0}'`;

result of above code I am getting

file1
      file2

[download]

Now I pass each file using foreach loop to parXML function

 foreach (@array) {
                       parXML($_);
                             }

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parXML function

sub parXML {

    my $file = shift;
    #print "$file\n";
    my $twig=XML::Twig->new(twig_handlers => {IP_ADDRESS => \&ip, COM=
+>\&co});
    $twig->set_pretty_print('indented');
    $twig->parsefile($file);

    sub ip {
        my($twig, $ip)= @_;
        print "Target:".$ip->text."\n";
        twig->print;
        $twig->purge;
    }

    sub co {
        my($twig, $co)= @_;
        $co->print;
        print "\n\n";
        $twig->purge;
    }
}

[download]

xml stored in file1 and file2

 
<REP>abc</REP>
 <ING>ip</ING>
 <IP_ADDRESS>192.168.67.16</IP_ADDRESS>
 <COM>
<DS>
<N>1</N>
</DS>
</COM>
<LIST>ac</LIST>

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<REP>ab</REP>
 <ING>ip</ING>
 <IP_ADDRESS>192.168.67.110</IP_ADDRESS>
 <COM>
<DS>
<N>5</N>
</DS>
</COM>
<LIST>gn</LIST>

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Result I am looking for in output

<IP_ADDRESS>192.168.67.16</IP_ADDRESS>
 <COM>
<DS>
<N>1</N>
</DS>
</COM>

[download]
<IP_ADDRESS>192.168.67.110</IP_ADDRESS>
 <COM>
<DS>
<N>5</N>
</DS>
</COM>

[download]

Replies are listed 'Best First'.
Re: Processing xml data in multiple files using XML::Twig and outputting in a file
by toolic (Bishop) on Apr 25, 2011 at 17:56 UTC
    • Didn't you get a Can't locate object method "print" via package "twig" warning (on STDERR)? twig->print; should be $twig->print;
    • I had to add root tags to your input files (again) to make them valid XML (I named them "top").
    • I changed twig_handlers to twig_roots to remove desired tags from your output (see XML::Twig).
    • I moved your ip/co subs outside of your parXml sub. This does not change the functionality, but I see no reason to declare a sub within a sub here. 
    use warnings;
use strict;
use XML::Twig;

my @array = qw(file1 file2);

foreach (@array) {
    parXML($_);
}

sub parXML {
    my $file = shift;
    #print "$file\n";
    my $twig=XML::Twig->new(twig_roots => {IP_ADDRESS => \&ip, COM=>\&
+co});
    $twig->set_pretty_print('indented');
    $twig->parsefile($file);
}

sub ip {
    my($twig, $ip)= @_;
    print "Target:".$ip->text."\n";
    $twig->print;
    $twig->purge;
}

sub co {
    my($twig, $co)= @_;
    $co->print;
    print "\n\n";
    $twig->purge;
}


__END__

Output to STDOUT:

Target:192.168.67.16
<top>
  <IP_ADDRESS>192.168.67.16</IP_ADDRESS>
</top>

  <COM>
    <DS>
      <N>1</N>
    </DS>
  </COM>

Target:192.168.67.110
<top>
  <IP_ADDRESS>192.168.67.110</IP_ADDRESS>
</top>

  <COM>
    <DS>
      <N>5</N>
    </DS>
  </COM>

    [download]

    On a side note, you can probably replace: 

    @array = `ls file* | awk '{print \$0}'`;

    [download]
    with: 
    @array = glob 'file*';

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