Windows cgihandler Error: Premature end of script headers

[Kevin Layman]

I've downloaded and installed Ruby (v1.8.5) w/the latest Windows
installer and am trying to run some cgi's per these examples:
http://microjet.ath.cx/webrickguide/html/CGIHandler.html

I keep getting HTTP 500 - Internal server error, and in the Ruby command
line PREMATURE END OF SCRIPT HEADERS.

I've got the path to the Ruby executable in test.cgi, and the next line
outputs a valid header, and this cgi will execute correctly when run by
Webrick directly. Programs are below.


test.cgi:
#!g:\ruby\bin\ruby.exe
print "Content-type: text/plain\r\n\r\n"
ENV.keys.sort.each{|k| puts "#{k} ==> #{ENV[k]}"}

cgi_handler.rb:
require 'webrick'

include WEBrick # let's import the namespace so
# I don't have to keep typing
# WEBrick:: in this documentation.

def start_webrick(config = {})
# always listen on port 8080
config.updatePort => 8080)
server = HTTPServer.new(config)
yield server if block_given?
['INT', 'TERM'].each {|signal|
trap(signal) {server.shutdown}
}
server.start

end

#start_webrickDocumentRoot =>
"g:/infoproweb/webfolder/cgi-bin/ruby",:CGIInterpreter =>
"g:/ruby/bin/ruby.exe")
start_webrickDocumentRoot => "g:/infoproweb/webfolder/")


start_webrick {|server|
#cgi_dir = File.expand_path('~/cgi-bin/ruby')
cgi_dir = "g:/infoproweb/webfolder/cgi-bin/ruby"
server.mount("/cgi-bin/ruby", HTTPServlet::FileHandler, cgi_dir,
{:FancyIndexing=>true})
}

 

[Kevin Layman]

Any suggestions at all on this would be greatly appreciated.

 

[Diego Guillen]

Any suggestions at all on this would be greatly appreciated.

Hi had the same problem recently in Windows (with Ruby 1.8.6-26), after
my script was already working in Ubuntu Linux.

I'm surprised that no one has provided an answer to this problem yet.

There could be several factors involved:
* your Windows security policies levels;
* what program gets associated with the execution of cgi scripts.

Doing a bit of debugging, I located the problem down to the last line on
the file: c:\ruby\lib\ruby\1.8\webrick\httpservlet\cgi_runner.rb
where is says: exec ENV["SCRIPT_FILENAME"]

I replaced that line with the following code:

# --- from here ---
Ruby = File::join:Config::CONFIG['bindir'],
::Config::CONFIG['ruby_install_name'])
Ruby << ::Config::CONFIG['EXEEXT']

if /mswin|bccwin|mingw/ =~ RUBY_PLATFORM
exec "#{Ruby}", ENV["SCRIPT_FILENAME"]
else
exec ENV["SCRIPT_FILENAME"]
end
# --- to here ---

This just builds a constant Ruby with the full path to "ruby.exe", and
(if you're running on Windows) passes it as an extra first parameter
"c:\ruby\bin\ruby.exe" , to the Kernel.exec() method.

Save the file and restart the server. It worked for me.

 

[Diego Guillen]

Hi again, I found the same problem more recently with Ruby 1.9.1 on
Windows.

A more generic solution that works for both Ruby 1.8.6.pxxx and 1.9.1.p0
on Windows is the following:

Edit the file: c:\ruby\lib\ruby\1.8\webrick\httpservlet\cgi_runner.rb

Add the following line at the top of the file:
if "1.9.1" == RUBY_VERSION
require 'rbconfig' #constants telling where Ruby runs from
end

Now, locate the last line where is says: exec ENV["SCRIPT_FILENAME"]
Comment that line out and add the following code:

# --- from here ---
if "1.9.1" == RUBY_VERSION #use RbConfig
Ruby = File::join(RbConfig::CONFIG['bindir'],
RbConfig::CONFIG['ruby_install_name'])
Ruby << RbConfig::CONFIG['EXEEXT']
else # use ::Config
Ruby = File::join:Config::CONFIG['bindir'],
::Config::CONFIG['ruby_install_name'])
Ruby << ::Config::CONFIG['EXEEXT']
end

if /mswin|bccwin|mingw/ =~ RUBY_PLATFORM
exec "#{Ruby}", ENV["SCRIPT_FILENAME"]
else
exec ENV["SCRIPT_FILENAME"]
end
# --- to here ---

Save the file and restart the webrick server.

Explanation:
This code just builds a constant 'Ruby' with the full path to
"ruby.exe", and
(if you're running on Windows) it passes the additional parameter
"c:\ruby\bin\ruby.exe" , to the Kernel.exec() method, so that your
script can be executed.