(defpackage :trivial-http   (:use :cl :trivial-sockets)   (:nicknames :thttp)   (:export :http-get :http-post :escape-url-query)) (in-package :trivial-http) (defun url-port (url)   (assert (string-equal url "http://" :end1 7))   (let ((path-start (position #\/ url :start 7)))     (let ((port-start (position #\: url :start 7 :end path-start)))       (if port-start (parse-integer url :start (1+ port-start) :junk-allowed t) 80)))) (defun url-host (url)   (assert (string-equal url "http://" :end1 7))   (let* ((port-start (position #\: url :start 7))          (host-end (min (or (position #\/ url :start 7) (length url))                         (or port-start (length url)))))     (subseq url 7 host-end))) (defconstant +crlf+   (if (boundp '+crlf+)       (symbol-value '+crlf+)       (concatenate 'string                    (string (code-char 13))                    (string (code-char 10))))) (defun response-read-code (stream)   (let* ((l (read-line stream))             (space (position #\Space l)))        (parse-integer l :start (1+ space) :junk-allowed t))) (defun response-read-headers (stream)   (loop for line = (read-line stream nil nil)      until (or (eql (length line) 0)                (eql (elt line 0) (code-char 13))                (eql (elt line 0) (code-char 10)))      collect        (let ((colon (position #\: line)))          (cons (intern (string-upcase (subseq line 0 colon)) :keyword)                (string-trim (list #\Space (code-char 13) (code-char 10))                             (subseq line (1+ colon))))))) (defun http-get (url)   (let* ((host (url-host url))          (port (url-port url))          (stream (open-stream host port)))     (format stream "GET ~A HTTP/1.0~AHost: ~A~AUser-Agent: Trivial HTTP for Common Lisp~A~A"             url +crlf+ host +crlf+ +crlf+ +crlf+)     (force-output stream)     (list      (response-read-code stream)      (response-read-headers stream)      stream))) (defun http-post (url content-type content)   (let* ((host (url-host url))          (port (url-port url))          (stream (open-stream host port)))     (format stream "POST ~A HTTP/1.0~AHost: ~A~AUser-Agent: Trivial HTTP for Common Lisp~AContent-Type: ~A~AContent-Length: ~D~A~A~A" url +crlf+ host +crlf+ +crlf+ content-type +crlf+ (length content) +crlf+ +crlf+ content)     (force-output stream)     (list      (response-read-code stream)      (response-read-headers stream)      stream))) ;; this next method stolen from Araneida (defun url-reserved-character-p (c)   (not (or (member c '(#\- #\_ #\. #\! #\~ #\* #\' #\( #\) ))            (alphanumericp c)))) (defun escape-url-query (query)   (apply #'concatenate 'string    (loop for c across query          if (url-reserved-character-p c)          collect (format nil "%~2,'0X" (char-code c))          else          collect (string c))))