;; @module cgi.lsp
;; @description Basic CGI processing tools for GET and POST requests
;; @version v 2.2 - comments redone for automatic documentation
;; @version v 2.3 - a fix in CGI:url-translate when translating utf-8 strings
;; @version v 2.4 - check for empty string when aquiring HTTP_COOKIE environment
;; @version v 2.5 - cleanup put-page for 10.0
;; @version v 2.6 - help text corrections
;; @version v 2.72 - help text corrections
;; @version v 2.8 - check for and use CONTENT_LENGTH when reading POST data
;; @version v 2.9 - eliminate deprecated integer -> int
;; @version v 2.91 - minor code cleanup in CONTENT_LENGTH handling
;; @version v 3.0 - handle multipart POST data. Added by Unya, Oct 2012
;; @version v 3.2 - fixed for large POST data
;; @author Lutz Mueller, Unya 2002-2012
;;
;; This module defines basic CGI processing tools for processing
;; CGI GET and POST requests and cookies.
;;
;; Include this file at the beginning of each file performing CGI processing using
;; either one of the following lines:
;;
;; (load "/usr/share/newlisp/cgi.lsp")
;; ; or as a shorter alternative
;; (module "cgi.lsp")
;;
;; Overview
;; On loading 'cgi.lsp' will retrieve 'GET', 'POST' and cookie
;; parameters via standard input and the environment variables:
;; 'QUERY_STRING' and 'HTTP_COOKIE'. These environment variables are set
;; by the webserver (tested with Apache 1.3). The webserver is receiving information
;; back from 'cgi.lsp' via std I/O channels.
;;
;; After having loaded this file all parameters from either 'GET' or 'POST'
;; method are stored as an association list and in 'CGI:params'
;; and individual parameters can be accessed using 'CGI:get'.
;;
;; All cookies can be accessed in an association list 'CGI:cookies' and
;; are accessed similar to the 'GET' and 'PUT' parameters using 'CGI:get-cookie'.
;; A function 'CGI:set-cookie' is available for setting cookies.
;;
;; The function 'CGI:put-page' outputs a HTML page to the webserver after
;; processing newLISP source embedded in '<%' and '%>' tags.
;;
;; 'CGI:params' and 'CGI:cookies' contain the empty list '()' when no
;; parameters or cookies are present
;;
;; The function 'CGI:put-page' can be used to output web pages containing
;; newLISP source embedded in <%, %> tags. Inside these tags are newLISP
;; statements printing output/HTML to the webpage.
(context 'CGI)
;; @syntax (CGI:put-page )
;; @param The HTML file containing '<%' and '%>' tags.
;; @return The page output to standard out.
;; Processes an HTML page by evaluating newLISP source
;; embedded into the HTML text between '<%' and '%>' tags.
;; The newLISP source typically contains 'print' and 'println'
;; statements to output strings to standard out.
;;
;; @example
;;
;;
;; <% (set 'site "example.com") %>
;; <% (print site) %>
;;
;;
;;
;; - will output -
;;
;;
;;
;; example.com
;;
;;
(define (put-page file-name , page start end)
(set 'page (read-file file-name))
(set 'start (find "<%" page))
(set 'end (find "%>" page))
(while (and start end)
(print (slice page 0 start))
(eval-string (slice page (+ start 2) (- end start 2)) MAIN)
(set 'page (slice page (+ end 2)))
(set 'start (find "<%" page))
(set 'end (find "%>" page)))
(print page))
;; @syntax (CGI:url-translate )
;; @param The URL formatted string to translate.
;; @return An ASCII formatted string.
;; Translates all URL formatted characters to ASCII. Translates '+' into spaces
;; and '%nn' hexdigits into characters. 'nn' is a 2-nibble hex number.
;;
;; @example
;; (CGI:url-translate "What+time+is+it%3f") => "What time is it?"
(define (url-translate str)
(replace "+" str " ")
(replace "%([0-9A-F][0-9A-F])" str (format "%c" (int (append "0x" $1))) 1))
; This is not an user function, but used internally.
;
; get-vars returns all parameter value pairs in an association list
; i.e.: ( ("name" "johndoe") ("password" "secret") )
; they can than be accessed using:
; (assoc "name" params) => "johndoe"
; where params is the return value from get-vars
(define (get-vars input , var value var-value)
(set 'vars (parse input "&"))
(dolist (elmnt vars)
(if (find "=" elmnt)
(begin
(set 'var (first (parse elmnt "=")))
(set 'value ((+ (find "=" elmnt) 1) elmnt)))
(begin
(set 'var elmnt)
(set 'value "")))
(push (list var (url-translate value)) var-value))
var-value) ; no necessary after v.9.9.5
; get QUERY_STRING parameters from GET method if present
;
(set 'params (env "QUERY_STRING"))
(if (not params) (set 'params ""))
(if params
(set 'params (get-vars params)))
; get POST data if present, use CONTENT_LENGTH variable
; if available
(if (env "CONTENT_LENGTH")
(when (= (env "REQUEST_METHOD") "POST")
(set 'post-data "")
(while (read (device) buffer (int (env "CONTENT_LENGTH")))
(write post-data buffer))
(let (boundary (when (regex "multipart/form-data; boundary=(.*)"
(env "CONTENT_TYPE")) (append "--" $1)))
; handle multi part form data
(if boundary
(let (data (parse (url-translate post-data) boundary))
(while data
(let (line (first data))
(setq data (rest data))
(when
(regex "Content-Disposition: form-data; name=\"(.*)\"\r\n\r\n(.*)$" line 4)
(push (list $1 (chop $2 2)) params) )
) ) )
(set 'params (get-vars post-data)))
) )
(begin
(set 'inline (read-line))
(when inline
(set 'params (get-vars inline)))
)
)
(if (not params) (set 'params '()))
; get cookies
;
(if (and (env "HTTP_COOKIE") (not (empty? (env "HTTP_COOKIE"))))
(dolist (elmnt (parse (env "HTTP_COOKIE") ";"))
(set 'var (trim (first (parse elmnt "="))))
(set 'value (slice elmnt (+ 1 (find "=" elmnt))))
(push (list var value) cookies))
(set 'cookies '()))
;; @syntax (CGI:set-cookie )
;; @param The cookie variable name as a string.
;; @param The cookie value as a string.
;; @param The domain where to set the cookie.
;; @param The path for the domain.
;; @return The string sent to standard out by 'CGI:set-cookie'.
;; This function should be called immedeately before
;; closing the header with '(print "Content-Type: text/html\r\n\r\n")',
;; which is typically the first statement in a CGI script written in
;; newLISP after the '(module "cgi.lsp")' statement.
;;
;; @example
;; (module "cgi.lsp")
;;
;; (CGI:set-cookie "password" "secret" "asite.com" "/somedir")
;; (print "Content-Type: text/html\r\n\r\n")
;; ...
(define (set-cookie var value domain path)
(set 'value (string value))
(print (format "Set-Cookie: %s=%s; domain=.%s; path=%s;\n" var value domain path)))
;; @syntax (CGI:get-cookie )
;; @param The string for the cookie variable name.
;; @return The string for the cookie value.
;; @example
;; (CGI:get-cookie "login") => "somebody"
(define (get-cookie keystr)
(lookup keystr cookies) )
;; @syntax (CGI:get )
;; @param The name of the 'GET' or 'POST' variable as a string.
;; @return The value string of the 'GET' or 'POST' variable.
(define (get keystr)
(lookup keystr params))
;; @example
;; (CGI:get "city") => "San Francisco"
(context 'MAIN)
; eof ;