I have a file with a really long string in it (it is actually XML but for some reason it is stored in 1 line). What I need to do is to do a substring search of the file and print out the "word" that contains the substring. This "word" might be a url, a description, etc. For coding and extraction purposes, the "word" is delineated by whitespace. So I need to back up to the beginning of the "word" an print out to the end of the "word."

Here is the code I have already but as you can see it uses an absolute substring size and I need it to be dynamic: 

while (<>) {
        my $istr = lc($_);
        my $offset = index($istr,"cesi");
        print $offset."\n";
        if ($offset > -1) {
                my $str = substr($istr, $offset-20, 100);
                print $str."\n";
        }
}

[download]

Thanks in advance for any input.

In reply to substring extraction by bfdi533

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