Perl正则表达式未在脚本中找到模式

Question

I'm reading the contents of a log file, performing a regex on the lines and putting the results in an array, but for some reason there is no output.

use strict;
use warnings;

my $LOGFILE = "log.file";
my $OUTFILE = "out.file";

open(LOG, "$LOGFILE") or die ("Could not open $LOGFILE: $!\n");
open(TMP, ">", "$OUTFILE") or die ("Could not open $OUTFILE: $!\n");

my @data = (<LOG> =~ /<messageBody>(.*?)<\/messageBody>/sg);

print TMP "This is a test line. \n";

foreach (@data){
   print "@data\n";
   print "\n=======================\n";
}

close TMP;
close LOG;

My output is a file (out.file) and the only content is "This is a test line." I know the regex works because I tried it at the prompt with: -lne 'BEGIN{undef $/} while (/(.*?)</messageBody>/sg) {print $1} log.file > test.file

What am I doing wrong?

Answer 1

If you want to print the data's items, then you should do something like this:

foreach $item (@data){
   print TMP "$item\n";
   print TMP "\n=======================\n";
}

$item will loop through all array items and will be written in TMP file

Answer 2

Your data likely spans lines.

You'll therefore need to slurp the entire thing before using your regex:

my $logdata = do {local $/; <LOG>};

my @data = $logdata =~ m{<messageBody>(.*?)</messageBody>}sg;