perl help to parse log file based on time input - perl

Question

Perl newbie here. I have a log file that I need to parse out "Backup succeeded" and any "Error:" entries. I tried parsing the log file by using unix cat and piping it to grep. I got the information that I want, but I would like try this in perl and to also have the option to pass a date parameter and give me the lines based on the date I need.
Sample of log file output: (Backup succeeded)
Wed Jun 09 06:14:25 2010: db2.cal.mil.mad:backup:INFO: flush-logs-time=00:00:00
Wed Jun 09 06:14:25 2010: db2.cal.mil.mad:backup:INFO: backup-time=06:14:23
Wed Jun 09 06:14:25 2010: db2.cal.mil.mad:backup:INFO: backup-status=Backup succeeded
Wed Jun 09 06:14:25 2010: db2.cal.mil.mad:backup:INFO: Backup succeeded
Sample of log file output: (Error:)
Wed Jun 09 05:00:03 2010: rip1.mil.mad:backup:ERROR: mysql-zrm appears to be already running for this backupset
Wed Jun 09 05:00:03 2010: rip1.mil.mad:backup:ERROR: If you are sure mysql-zrm is not running, please remove the file /etc/mysql-zrm/rip1.mail.mad/.mysql-zrm.pid and restart mysql-zrm
**I would like a text and/or email with this information. Like so, but with the option to pass in the date I need.
Wed Jun 09 05:00:03 2010: rip1.mil.mad:backup:ERROR: mysql-zrm appears to be already running for this backupset
Wed Jun 09 05:00:03 2010: rip1.mil.mad:backup:ERROR: If you are sure mysql-zrm is not running, please remove the file /etc/mysql-zrm/rip1.mail.mad/.mysql-zrm.pid and restart mysql-zrm
Wed Jun 09 06:14:25 2010: db2.cal.mil.mad:backup:INFO: backup-status=Backup succeeded
If you would please provide me with some perl code and/or ideas to get started. I would appreciate the help. Thank you.

Answer 1

#!/usr/bin/perl
# usage example: <this script> Jun 09 2010 <logfile>
use strict;
use warnings;
my ($mon,$day,$year) = ($ARGV[0],$ARGV[1],$ARGV[2]);
open(FH,"< $ARGV[3]") or die "can't open log file $ARGV[3]: $!\n";
while (my $line = <FH>) {
if ($line =~ /.* $mon $day \d{2}:\d{2}:\d{2} $year:.*(ERROR:|Backup succeeded)/) {
print $line;
}
}

Answer 2

Here's a simple script. The file name to scan and the target date are hard-coded. Matches are printed to STDOUT.
BTW, this code is totally untested. I typed it into the text box in my browser.
use strict;
use warnings;
my $logpath = './bar/log';
my $target = 'Jun 09 2010';
open my $fh, '<', $logpath or die "Error opening $logpath $!\n";
while (my $line = <$fh> ) {
next unless date_match( $target, $line );
next unless my $result = got_error($line) // got_backup($line);
print $result;
}
sub got_backup {
my $line = shift;
return unless $line =~ /backup-status=Backup succeeded/;
return $line;
}
sub got_error {
my $line = shift;
return unless $line =~ /:ERROR:/;
return $line;
}
# Take a line and a target date. Compare the date derived from the line to
# the target, and returns true if they match.
# Also always returns true if target is not defined
sub date_match {
my $target = shift;
my $line = shift;
return 1 unless defined $target; # Always true if target is undefined.
# Where did that god-awful date format come from? Yech.
my $date = extract_date($line);
return $date eq $target;
}
# Simple extract of date using split and join with extra variables
# to make it newbie friendly.
# IMO, it would be a good idea to switch to using DateTime objects and
# DateTime::Format::Strptime
sub extract_date {
my $line = shift;
my #parts = split /:/, $line;
my $date = join ':' #parts[0..2];
#parts = split /\s+/, $date;
$date = #parts[1,2,4];
return $date;
}
You can use Getopt::Long to get a filename and target date.
It would be a good idea to use a more robust date/time parsing and comparison scheme. DateTime and friends are very good, powerful modules for date manipulation. Check them out.
If you are processing tons of data and need to be more efficient, you can avoid copying $line everywhere in a number of ways.
For future reference, if you post a little code, you'll get better responses