--- a/fetch_weather.pl	Tue Jun 03 13:06:13 2014 +0300
+++ b/fetch_weather.pl	Tue Jun 03 15:10:47 2014 +0300
@@ -19,6 +19,7 @@
   "outfile" => "",
 );
 
+
 ###
 ### Helper functions
 ###
@@ -28,6 +29,24 @@
 }
 
 
+sub fetch_http($)
+{
+  my $tmpAgent = LWP::UserAgent->new;
+  $tmpAgent->agent("Mozilla/4.0 (compatible; MSIE 6.0; MSIE 5.5; Windows NT 6.0) Opera 10.63  [en]");
+  $tmpAgent->timeout(10);
+
+  my $tmpRequest = HTTP::Request->new(GET => $_[0]);
+  
+  return $tmpAgent->request($tmpRequest);
+}
+
+
+sub parse_timestamp($$)
+{
+  return str2time($_[0]) - str2time("00:00") + $_[1];
+}
+
+
 sub str_trim($)
 {
   my $str = $_[0];
@@ -39,6 +58,9 @@
 }
 
 
+###
+### Loose HTML parser
+###
 sub pop_token_a($)
 {
   my $tokens = $_[0];
@@ -159,6 +181,10 @@
 }
 
 
+###
+### Helper functions for locating/traversing nodes
+### in the parsed data tree structure.
+###
 sub fnode($$)
 {
   return html_find_node($_[0], $_[1], "");
@@ -171,32 +197,14 @@
 }
 
 
-sub fetch_http($)
-{
-  my $tmpAgent = LWP::UserAgent->new;
-  $tmpAgent->agent("Mozilla/4.0 (compatible; MSIE 6.0; MSIE 5.5; Windows NT 6.0) Opera 10.63  [en]");
-  $tmpAgent->timeout(10);
-
-  my $tmpRequest = HTTP::Request->new(GET => $_[0]);
-  
-  return $tmpAgent->request($tmpRequest);
-}
-
-
 sub get_node($$$)
 {
   return defined($_[0]->[$_[2]]{"nodes"}[0]{$_[1]}) ? $_[0]->[$_[2]]{"nodes"}[0]{$_[1]} : "";
 }
 
 
-sub parse_timestamp($$)
-{
-  return str2time($_[0]) - str2time("00:00") + $_[1];
-}
-
-
 ###
-### Configuration
+### Configuration handling
 ###
 sub opt_chk_bool($)
 {
@@ -290,10 +298,13 @@
 "Usage: $0 <config file>\n"
 ) unless scalar(@ARGV) >= 1;
 
-opt_read_config(shift) == 0 or exit;
+my $cfgfile = shift;
+opt_read_config($cfgfile) == 0 or die("Errors while parsing configuration file '".$cfgfile."'.\n");
 
 
-### Fetch tiehallinto data
+###
+### Fetch tiehallinto road weather measurement data
+###
 if (opt_chk_bool("opt_tiehallinto"))
 {
   for (my $i = 1; $i <= 22; $i++)
@@ -350,7 +361,10 @@
   }
 }
 
+
+###
 ### Fetch FMI data
+###
 if (opt_chk_bool("opt_fmi"))
 {
   die("FMI data scrape enabled, but no API key set.\n") unless opt_chk_valid("fmi_api_key", 10);
@@ -392,7 +406,9 @@
 }
 
 
+###
 ### Output
+###
 if (opt_chk_valid("outfile", 1)) {
   open(STDOUT, '>', opt_get("outfile")) or die("Could not open output file '".opt_get("outfile")."'.\n");
 }