Rather than reinventing the wheel, use one of the many available CPAN modules that know how to parse and generate (read and write) XML. Look in the XML namespace on CPAN.

Start by writing a small program to locate the author and afiil nodes in a stripped-down version of your a.txt and print what it finds. If you run into difficulties, show us

• your small XML input file
• what information you want to output
• the program you wrote
• the output you actually got

and you will get lots of help from Perlmonks.

Hai Narveson,

Thank you for considering me, let me tell you straight, There are two file a.txt and b.txt, i want each line of text in a.txt should be searched, if searched text found in b.txt then it has to replace with a newline along with the searched text, i hope so this will be clear to you.

Regards,

Sriram

How about you show us a very small sample data set and the code you are having trouble with along with the output you get and the output you expect.

Note that for small samples it is convenient to use strings as the input files and to print output. Consider:

use strict;
use warnings;

my $fileA = <<FILEA;
Thank you for considering me.
Let me tell you straight, there are two file a.txt and b.txt.
I want each line of text in a.txt should be searched
FILEA
my $fileB = <<FILEB;
txt
FILEB

my @words;

open my $bIn, '<', \$fileB or die "Open fileB failed: $!";
while (<$bIn>) {
    chomp;
    push @words, $_;
}
close $bIn;

my $match = join '|', @words;

open my $aIn, '<', \$fileA or die "Open fileA failed: $!";

while (<$aIn>) {
    next unless /\b($match)\b/;
    
    print;
}
close $aIn;
[download]

Prints:

Let me tell you straight, there are two file a.txt and b.txt.
I want each line of text in a.txt should be searched
[download]

which reads a "file" containing a list of words - one per line, then prints lines from a second "file" that contain any word from the list. Not the job you want to do I know, but I can't yet tell what it is that you do want to do!

---

Perl is environmentally friendly - it saves trees

Hai Narveson,

Sorry Narveson, as i am new to this forum by absently i posted my reply in the comments, i am extremely sorry!

Thank you for considering me, let me tell you straight, There are two file a.txt and b.txt, i want each line of text in a.txt should be searched, if searched text found in b.txt then it has to replace with a newline along with the searched text, i hope so this will be clear to you.

Regards,

srprabu

Do you want the content of b.txt to be entered into the xml of a.txt, under what conditions?

To delete the content of the <!..> tag

$line=~s/<![^>]*>/<!>/;

Consider:

my $line = '<!-- Gone > Not gone -->';

$line =~s/<![^>]*>/<!>/;
print $line;
[download]

Prints:

<!> Not gone -->
[download]

which most likely is not the expected result.

---

Perl is environmentally friendly - it saves trees

Hai,

Thank you for considering me, let me tell you straight, There are two file a.txt and b.txt, i want each line of text in a.txt should be searched, if searched text found in b.txt then it has to replace with a newline along with the searched text, i hope so this will be clear to you.

The code which you gave for replace is working only if the text come in between the open tag and closed tag,

For example

<! This is the sample text > -- For this the search is working fine.

<! This is the <i>sample</i> text > -- For this the search is working till the italic closing tag not the actual closing tag.

Regards,

Srprabu