From 45a127523e7f4b9ef7a81dc4370e390c5d153ee0 Mon Sep 17 00:00:00 2001
From: Karai Csaba <cskarai@freemail.hu>
Date: Thu, 5 May 2016 07:32:46 +0200
Subject: [PATCH] Dummy web server skeleton

---
 examples/dummy-web-server.pl | 202 +++++++++++++++++++++++++++++++++++
 1 file changed, 202 insertions(+)
 create mode 100755 examples/dummy-web-server.pl

diff --git a/examples/dummy-web-server.pl b/examples/dummy-web-server.pl
new file mode 100755
index 0000000..8b72dde
--- /dev/null
+++ b/examples/dummy-web-server.pl
@@ -0,0 +1,202 @@
+#!/usr/bin/perl
+use strict;
+
+use IO::Socket::INET;
+use Data::Dumper;
+use File::Basename;
+
+# auto-flush on socket
+$| = 1;
+ 
+# creating a listening socket
+my $server = new IO::Socket::INET (
+    LocalHost => '0.0.0.0',
+    LocalPort => '7777',
+    Proto => 'tcp',
+    Listen => 5,
+    Reuse => 1
+);
+die "cannot create socket $!\n" unless $server;
+print "server waiting for client connection on port 7777\n";
+ 
+
+my $client;
+
+while ($client = $server->accept())
+{
+   my $pid ;
+   while (not defined ($pid = fork()))
+   {
+     sleep 5;
+   }
+   if ($pid)
+   {
+       close $client;        # Only meaningful in the client 
+   }
+   else
+   {
+       $client->autoflush(1);    # Always a good idea 
+       close $server;
+       
+       my $httpReq = parse_http( $client );
+       print Dumper($httpReq);
+       my $httpResp = process_http( $httpReq );
+       print Dumper($httpResp);
+
+       my $data = "HTTP/1.1 " . $httpResp->{code} . " " . $httpResp->{text} . "\r\n";
+       
+       if( exists $httpResp->{fields} )
+       {
+         for my $key( keys %{$httpResp->{fields}} )
+         {
+           $data .= "$key: " . $httpResp->{fields}{$key} . "\r\n";
+         }
+       }
+       $data .= "\r\n";
+       if( exists $httpResp->{body} )
+       {
+         $data .= $httpResp->{body};
+       }
+ 
+ print "$data\n\n";
+       $client->send($data);
+ 
+       if( $httpResp->{done} )
+       {
+         # notify client that response has been sent
+         #shutdown($client, 1);
+       }
+   }
+}
+
+exit(0);
+
+sub parse_http
+{
+  my ($client) = @_;
+    # read up to 1024 characters from the connected client
+    my $data = "";
+    
+    do{
+      my $buf = "";
+      $client->recv($buf, 1024);
+      $data .= $buf;
+    }while( $data !~ /\r\n\r\n/s );
+    #print "Query: $data\n";
+ 
+    my %resp;
+    
+    my @lines = split /\r\n/, $data;
+    my $head = shift @lines;
+    
+    if( $head =~ /(GET|POST) / )
+    {
+      $resp{method} = $1;
+      $head =~ s/(GET|POST) //;
+      if( $head =~ /^([^ ]+) HTTP\/\d\.\d/ )
+      {
+        $resp{url} = $1;
+        
+        my %fields;
+        while( my $arg = shift @lines )
+        {
+          if( $arg =~ /^([\w-]+): (.*)$/ )
+          {
+            $fields{$1} = $2;
+          }
+        }
+        $resp{fields} = \%fields;
+      }
+      else
+      {
+        $resp{method} = 'ERROR';
+        $resp{error} = 'Invalid HTTP request';
+      }
+    }
+    else
+    {
+      $resp{method} = 'ERROR';
+      $resp{error} = 'Invalid HTTP request';
+    }
+    
+    return \%resp;
+}
+
+sub error_response
+{
+  my ($code, $msg) = @_;
+
+  my %resp;
+  $resp{code} = $code;
+  $resp{text} = $msg;
+  $resp{fields} = {};
+  $resp{done} = 1;
+  
+  return \%resp;
+}
+
+sub slurp
+{
+  my ($file) = @_;
+  
+  open IF, "<", $file or die "Can't read file: $!";
+  my @fc = <IF>;
+  close(IF);
+  my $cnt = join("", @fc);
+  return $cnt;
+}
+
+sub process_http
+{
+  my ($httpReq) = @_;
+  if( $httpReq->{method} eq 'ERROR' )
+  {
+    return error_response(400, $httpReq->{error});
+  }
+  
+  if( $httpReq->{method} eq 'GET' )
+  {
+    my $url = $httpReq->{url};
+    $url =~ s/^\///;
+    
+    $url = "home.html" if ! $url;
+
+    my $pth = dirname $0;
+    
+    if( -f "$pth/../html/$url" )
+    {
+      my $cnt = slurp( "$pth/../html/$url" );
+      
+      if( $url =~ /\.html$/ )
+      {
+        my $prep = slurp( "$pth/../html/head-" );
+        $cnt = "$prep$cnt";
+      }
+      
+      my %resp;
+      $resp{code} = 200;
+      $resp{text} = "OK";
+      $resp{done} = 1;
+      $resp{body} = $cnt;
+      
+      $resp{fields} = {};
+      $resp{fields}{'Content-Length'} = length($cnt);
+      
+      $resp{fields}{'Content-Type'} = "text/html; charset=UTF-8" if( $url =~ /\.html$/ );
+      $resp{fields}{'Content-Type'} = "text/css" if( $url =~ /\.css$/ );
+      $resp{fields}{'Content-Type'} = "text/javascript" if( $url =~ /\.js$/ );
+      $resp{fields}{'Content-Type'} = "image/gif" if( $url =~ /\.ico$/ );
+      $resp{fields}{'Connection'} = 'close';
+      
+      return \%resp;
+    }
+    else
+    {
+      return error_response(404, "File not found");
+    }
+  }
+  
+  # TODO
+  
+  return error_response(400, "Invalid HTTP request");
+}