in reply to Re^3: Real time log parser
in thread Real time log parser

Here's what I'm trying to do in general. As I said before, I'm new to perl so my code be so-so, but it worked from the command line, and now I'm trying to make it work with File::Tail: 
#!/usr/bin/perl
# Squid reconfiguration script rev: 0.87
#
    use File::Tail;
my (@tmpl,@cut);

sub ban {
open( CFG, "<", "/etc/squid/squid.conf" );
    while ( <CFG> ) {
    push @cfg, $_;
    }
close(CFG);

my @cutoff = grep /proxy_/,@_;
s/ROUNDROBIN_PARENT\///g for @cutoff;
@cutoff = grep /@cutoff/,@cfg;

    open( GREY, ">", "/etc/squid/all.grey" );

  if (@cutoff) {
            print GREY @cutoff;
            print GREY "10\n";
}
close (GREY);

print "Banned parrent: @cutoff\n";
print " Strings with parrent in conf: @cutoff\n";

open( EXC, ">", "/etc/squid/squid.conf" );
my %dels = map { $_ => 1 } @cutoff;
@cfg = grep !$dels{$_}, @cfg;
print EXC @cfg;
close (EXC);
@args = ("/etc/init.d/squid", "reload");
system(@args) == 0 or die "system @args failed: $?" ;
}

my $name = "/var/log/squid/access.log";
my $ref=tie *FH,"File::Tail",(name=>$name);
     while (<FH>) {
        my $res = ban ($_);
        m/\/sorry\// && ban ($_);

}

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Re^5: Real time log parser
by Eliya (Vicar) on Jan 02, 2012 at 20:20 UTC 
    my @cutoff = grep /proxy_/,@_;
s/ROUNDROBIN_PARENT\///g for @cutoff;
@cutoff = grep /@cutoff/,@cfg;

    [download]

    I'm not sure what this is supposed to be doing, but it somehow looks suspicious ;)   In @_ you have one line — as read from FH and passed to ban() ... What do those lines look like, and what do you expect to be in @cutoff after those three lines have executed?

    You said it worked from the command line.  How did you call it for this?

    P.S.: please indent your code properly.  You'll not only do us a favor, but yourself, too, in the long run...

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      Sorry for such code, I'm just getting starting with perl and on perlmonks.org. So, line that should be passed to a ban() script as is, if regexp matches:

      1325521875.165 93 127.0.0.1 TCP_MISS/302 667 GET http://www.google.co.uk/sorry/?continue=http://www.google.co.uk/search%3Fq%3Just+an+axample - ROUNDROBIN_PARENT/proxy_218 text/html

      my @cutoff = grep /proxy_/,@_;
s/ROUNDROBIN_PARENT\///g for @cutoff;
@cutoff = grep /@cutoff/,@cfg;

      [download]
      Should left in @cutoff after second line: proxy_218 In third line script must search against squid.conf strings with proxy_218, and it shuould find:

      cache_peer 111.222.121.1 parent 60099 0 no-query no-digest originserver name=proxy_218 round-robin login=login:pass connect-timeout=3

      cache_peer_access proxy_218 allow all

      These lines must be moved to some file, and squid must be reloaded. I've executed my script like this:

      # ./MY__SCRIPT.pl 1325521875.165 93 127.0.0.1 TCP_MISS/302 667 GET http://www.google.co.uk/sorry/?continue=http://www.google.co.uk/search%3Fq%3Just+an+axample - ROUNDROBIN_PARENT/proxy_218 text/html

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        Your main problem is that you need to split the line you're passing to ban() 

            m|/sorry/| && ban(split ' ', $_);

        [download]

        With that input, your above three lines would start to make some sense.

        Thing is that, in contrast to command line arguments, a string you pass as one parameter to a subroutine is not automatically split.  I.e., when you say on the command line 

        # ./script.pl foo bar baz

        [download]

        you get the three words "foo", "bar", "baz" as separate elements in the array @ARGV (which I suppose you were using in the working command line version in place of @_). This is because the shell splits the command line on whitespace, before the arguments are placed in @ARGV.

        OTOH, when you pass "foo bar baz" as a single string to a subroutine, it is left as is, so the array @_ holds one element, which is the entire string.  In other words, after your grep for /proxy_/, you still have the entire string in @cutoff — and the rest of the code stops working...

        That said, you could also leave your ban($_) call as is, and simply extract the relevant part of the string with a regex capture: 

        sub ban {
    my $line = shift;
    ...

    my ($proxy) = $line =~ m| - \S+/(proxy_\S+)|;
    my @cutoff = grep /$proxy/, @cfg;
    ...

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