From: Matthew Vernon <matthewv@chiark.greenend.org.uk>
Date: Tue, 15 Apr 2014 15:53:15 +0000 (+0100)
Subject: Reverse the contents of log files
X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~webstump/git?p=modbot-uram.git;a=commitdiff_plain;h=66ffdf9bce6ef1b3f5b4252eedb01538f114ba8e

Reverse the contents of log files

Use "tac" to reverse files, meaning the logs are now output neatly in
reverse-chronological order.

The existing code tried to read everything in $webstump_home/.. ; we
now only try and open errs files; this involves changing the guard
condition to 0 from undef (since forwards * undef isn't undef).
---

diff --git a/webstump/scripts/html_output.pl b/webstump/scripts/html_output.pl
index 5503b4a..6ee3295 100644
--- a/webstump/scripts/html_output.pl
+++ b/webstump/scripts/html_output.pl
@@ -640,22 +640,24 @@ sub scanlogs ($$$) {
     my $num= sub {
         local ($_) = @_;
         return $forwards * (
-            m/^errs$/ ? -1 :
-            m/^errs\.(\d+)(?:\.gz$)$/ ? $1 :
-            undef
+            m/^errs$/ ? 1 :
+            m/^errs\.(\d+)(?:\.gz$)$/ ? ($1+2) :
+            0
                            );
     };
     foreach my $leaf (
                       sort { $num->($a) <=> $num->($b) }
-                      grep { defined $num->($_) }
+	              grep { $num->($_) }
                       readdir LOGSDIR
                       ) {
         my $file= "$dir/$leaf";
-        if ($file =~ m/\.gz$/) {
-            open LOGFILE, "zcat $file |" or die "zcat $file $!";
+        if ($file =~ m/\/errs.*\.gz$/) {
+            open LOGFILE, "zcat $file | tac |" or die "zcat $file | tac $!";
+        } elsif ($file =~ /errs/) {
+            open LOGFILE, "tac $file |" or die "tac $file $!";
         } else {
-            open LOGFILE, "< $file" or die "$file $!";
-        }
+	    die "Unexpected filename in scanlogs: $file";
+	}
         while (<LOGFILE>) {
             my $tgot= $callback->();
             next unless $tgot;