[DOC] Using Red as CGI

To use Red as CGI, you must configure your server to support Red executable. For Apache, see https://httpd.apache.org/docs/current/howto/cgi.html .

Basic example script would then look like this:

#!/usr/local/bin/red ; replace this with your path to Red executable
Red[]
print "Content-type: text/html^/"
print rejoin ["Hello world from Red " system/version]

to print the HTTP header:

call/wait/output "printenv" o: "" print o

If you want to process data passed to CGI, I suggest using HTTP tools that will read HTTP headers and parse them to http-headers object. This object has same structure as Rebol's system/options/cgi, described here.

For the GET method, query string is in http-headers/query-string.

For the POST method, you can get the POST data using input or read-stdin:

#!/usr/local/bin/red
Red[]
print "Content-type: text/html^/"
print rejoin ["Post data: " mold input]

Please note that input is good for textual data only if you want to get binary data, you need to use read-stdin and pre-allocate binary buffer:

#!/usr/local/bin/red
Red[]
length: 100'000
read-stdin data: make binary! length length
print "Content-type: text/html^/"
print rejoin ["Post data: " mold read-stdin]

Be sure that you allocate big enough buffer, as read-stdin won't auto expand the buffer.

Under IIS 8.5

To use Red as CGI under IIS, follow the instructions below:

• Find the compiled console executable (mostly under C:\ProgramData\Red)
• Copy and rename the Red console application to somewhere that IIS can reach and execute
• Open Internet Information Services Manager, go to your site settings, select Handler Mappings and select Add Module Mapping
• Type *.red to Request Path, <path>\redconsole.exe "%s" to Executable, Red to Name
• Select Yes for allow this ISAPI extension? question
• Under CGI, set Use New Console For Each Invocation to true. Otherwise you get 502.2 - Bad Gateway. SetConsoleTitle failed! error.

If you use red.exe instead of compiled red console application, then don't forget to put --cli for Executable settings: <path>\red.exe --cli "%s". Otherwise you get 502.2 - Bad Gateway. "" (empty header error)

Under Cheyenne Web Server

For details see https://www.cheyenne-server.org/about.shtml

Add .red extension to bind-extern in globals section in httpd.cfg file:

globals [
  listen [80 81 82] ;can listen multiple ports
  bind-extern CGI to [.cgi .red] ;you can use any extension you want
  bind-extern RSP to [.rsp]
  worker-libs [
    ...

Reload config or restart Cheyenne.

Then create a file named test.red under www, change the path to your red executable or the pre-compiled console executable in the first line of your script:

#!/E/Server/cheyenne/www/red-console.exe
Red []
print "Content-type: text/html^/"
print now

Now you are ready to test. Open a browser and point to localhost/test.red you should see the output of your script.

Lighttpd Web Server on OS X Mojave

To use Red as CGI under lighttpd, follow the instructions below:

Install HomeBrew by copying this line into the Terminal

/usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"

then install Lighttpd by typing this into the terminal:

brew install lighttpd

then open the following file: /usr/local/etc/lighttpd/lighttpd.conf

and add index.red like you see below:

index-file.names += (
  "index.xhtml", "index.html", "index.htm", "default.htm", "index.red", "index.php"
)

then add the .red extension like you see below so red files can be executed:

static-file.exclude-extensions = ( ".php", ".pl", ".fcgi", ".scgi", ".red" )

then open the file located at /usr/local/etc/lighttpd/conf.d/cgi.conf and add .red like you see below:

cgi.assign                 = ( ".pl"  => "/usr/bin/perl",
                               ".cgi" => "/usr/bin/perl",
                               ".rb"  => "/usr/bin/ruby",
                               ".erb" => "/usr/bin/eruby",
                               ".red" => "/usr/local/bin/red.dms",
                               ".py"  => "/usr/bin/python" )

finally open this file:

/usr/local/etc/lighttpd/lighttpd/modules.conf

and un-comment this line:

include "conf.d/cgi.conf"

then start the server by typing this into the terminal:

lighttpd -f /usr/local/etc/lighttpd/lighttpd.conf

when you submit an HTML form POST in RED use the function input to read the text being sent

it will take some time the first time since RED will be compiling