racket/collects/net/sendurl.rkt
Eli Barzilay debd1f9f1e Recketizing much in `net/*', mass ".ss" -> ".rkt" conversion in .scrbl files.
(Some other minor things here and there.)
2011-06-20 04:27:14 -04:00

256 lines
11 KiB
Racket

;; The main client of this module is browser/external.rkt
;; (others just use the (send-url url [new?]) interface.)
#lang racket/base
(require racket/system racket/file racket/promise racket/port)
(provide send-url send-url/file send-url/contents
unix-browser-list browser-preference? external-browser)
(define separate-by-default?
;; internal configuration, 'browser-default lets some browsers decide
(get-preference 'new-browser-for-urls
(lambda () 'browser-default)
#:timeout-lock-there (lambda (path) 'browser-default)))
;; all possible unix browsers, filtered later to just existing executables
;; order matters: the default will be the first of these that is found
(define all-unix-browsers
'(;; common browsers
;; xdg-open
firefox google-chrome galeon opera mozilla konqueror seamonkey epiphany
;; known browsers
camino skipstone
;; broken browsers (broken in that they won't work with plt-help)
;; this is a configurable thing that is deprecated, but better
;; than gnome-open (because it works)
htmlview
;; gnome-open could be high, but the problem is that it doesn't
;; handle file:// URLs with a query string.
gnome-open
;; dillo does not have javascript
dillo
;; ancient browsers
netscape mosaic
))
;; : any -> bool
(define (custom-browser? x)
(and (pair? x) (string? (car x)) (string? (cdr x))))
(define external-browser
(make-parameter
#f ; #f means "consult the preferences file"
(lambda (x)
(if (browser-preference? x)
x
(error 'external-browser "~e is not a valid browser preference" x)))))
;; by-need filtering of found unix executables
(define existing-unix-browsers->exes
(delay/sync
(filter values
(map (lambda (b)
(let ([exe (find-executable-path (symbol->string b) #f)])
(and exe (cons b exe))))
all-unix-browsers))))
(define existing-unix-browsers
(delay/sync (map car (force existing-unix-browsers->exes))))
(define-syntax unix-browser-list
(syntax-id-rules (set!)
[(_ . xs) ((force existing-unix-browsers) . xs)]
[(set! _ . xs) (error 'unix-browser-list "cannot be mutated")]
[_ (force existing-unix-browsers)]))
;; : any -> bool
(define (browser-preference? x)
(or (not x) (memq x unix-browser-list) (custom-browser? x) (procedure? x)))
;; like (system-type), but return the real OS for OSX with XonX
;; (could do the same for Cygwin, but it doesn't have shell-execute)
(define systype
(delay/sync (let ([t (system-type)])
(cond [(not (eq? t 'unix)) t]
[(regexp-match? #rx"-darwin($|/)"
(path->string (system-library-subpath)))
'macosx]
[else t]))))
(define (%escape str)
(apply string-append
(map (lambda (b)
(string-append "%" (if (< b 16) "0" "") (number->string b 16)))
(bytes->list (string->bytes/utf-8 str)))))
;; Used for quoting characters that will not work well in shell quotes, and
;; only these characters. This is only for protection when passing arguments
;; to subprocesses, it's best to pass properly escaped urls to `send-url'.
(define (escape-url url)
(regexp-replace* #px"(?:[^[:graph:]]|[$\"'`\\\\])" url %escape))
;; send-url : str [bool] -> void
(define (send-url url-str [separate-window? separate-by-default?]
#:escape? [escape? #t])
(define stype (force systype))
(unless (string? url-str)
(error 'send-url "expected a string, got ~e" url-str))
(let ([url-str (if escape? (escape-url url-str) url-str)])
(if (procedure? (external-browser))
((external-browser) url-str)
(case stype
[(macosx) (send-url/mac url-str)]
[(windows) (send-url/win url-str)]
[(unix) (send-url/unix url-str separate-window?)]
[else (error 'send-url
"don't know how to open URL on platform: ~s" stype)])))
(void))
(define (send-url/file path [separate-window? separate-by-default?]
#:fragment [fragment #f] #:query [query #f])
(let* ([path (path->string (path->complete-path path))]
[path (if (eq? 'windows (force systype))
;; see http://msdn2.microsoft.com/en-us/library/ms775098.aspx
(let* ([path (regexp-replace* #rx"\\\\" path "/")]
[slashes (cdar (regexp-match-positions #rx"^/*" path))])
(case slashes
[(0) (string-append "/" path)]
[(1) (error 'send-url/file
"unexpected path, please submit a bug: ~s"
path)]
[else (substring path 2)]))
path)]
[path (regexp-replace* #rx"[^A-Za-z0-9_./:-]" path %escape)]
[path (string-append "file://" path)]
[path (if query (string-append path "?" (escape-url query)) path)]
[path (if fragment (string-append path "#" (escape-url fragment))
path)])
(send-url path separate-window? #:escape? #f)))
;; See the documentation for the `delete-at' argument
(define (send-url/contents contents [separate-window? separate-by-default?]
#:fragment [fragment #f] #:query [query #f]
#:delete-at [delete-at #f])
(define tmp-tmpl "plt-sendurl-contents-file-~a.html")
(define tmp-rx #rx"^plt-sendurl-contents-file-.*\\.html$")
;; The code below will often leave leftovers (for example, plt-help will quit
;; before deletion happens), so every once in a while, do a cleanup. This
;; can also remove files that were created with no intention for deletion
;; (when delete-at is #f), so don't remove files that are less than 15
;; minutes old.
(when (zero? (random 5))
(parameterize ([current-directory (find-system-path 'temp-dir)])
(let ([now (current-seconds)])
(for ([file (directory-list)]
#:when (and (file-exists? file)
(regexp-match tmp-rx (path-element->string file))
(> (- now (file-or-directory-modify-seconds file))
(* 15 60))))
;; The temp directory may be shared with other users, so silently
;; ignore failures to remove files.
(with-handlers ([void void]) (delete-file file))))))
(let ([temp (make-temporary-file tmp-tmpl)])
(with-output-to-file temp #:exists 'truncate
(lambda () (display contents)))
(when delete-at (thread (lambda () (sleep delete-at) (delete-file temp))))
(send-url/file temp)))
(define osascript (delay/sync (find-executable-path "osascript" #f)))
(define (send-url/mac url)
(browser-run (force osascript) "-e" (format "open location \"~a\"" url)))
(define (send-url/unix url separate-window?)
;; in cases where a browser was uninstalled, we might get a preference that
;; is no longer valid, this will turn it back to #f
(define (try pref)
(if (symbol? pref)
(if (memq pref unix-browser-list) pref #f)
pref))
(define browser
(or (try (external-browser))
(try (get-preference 'external-browser))
;; no preference -- chose the first one from the filtered list
(and (pair? unix-browser-list) (car unix-browser-list))))
(define exe
(cond [(assq browser (force existing-unix-browsers->exes)) => cdr]
[else #f]))
(define (simple) (browser-run exe url))
(define (w/arg a) (browser-run exe a url))
(define (try-remote)
(or (system* exe "-remote" (format "openURL(~a~a)" url
(if separate-window? ",new-window" "")))
(simple)))
(cond
[(not browser)
(error 'send-url "Couldn't find a browser to open URL: ~e" url)]
[(custom-browser? browser)
(browser-run #:shell #t (string-append (car browser) url (cdr browser)))]
;; if it's a known browser, then it must be an existing one at this point
[(not exe) (error 'send-url "internal error")]
;; if it's gone throw an error (refiltering will break assumptions of
;; browser/external.rkt, and we really mimic the Win/Mac case where there
;; should be some builtin facility that doesn't change)
[(not (file-exists? exe)) (error 'send-url "executable vanished: ~a" exe)]
;; finally, deal with the actual browser process
[else
(case browser
[(xdg-open gnome-open firefox konqueror dillo htmlview google-chrome)
(simple)]
;; don't really know how to run these
[(camino skipstone mosaic) (simple)]
[(galeon) (if (eq? 'browser-default separate-window?)
(simple) (w/arg (if separate-window? "-w" "-x")))]
[(epiphany) (if separate-window? (w/arg "--new-window") (simple))]
[(mozilla seamonkey netscape) (try-remote)]
[(opera)
;; opera starts a new browser automatically
(browser-run exe "-remote"
(format "openURL(~a~a)"
url (if separate-window? ",new-window" "")))]
[else (error 'send-url "internal error")])]))
;; Windows has a bug when using `shell-execute' or when running `iexplore.exe'
;; directly -- it silently drops the fragment and query from URLs that have
;; them. This is described at
;; http://support.microsoft.com/default.aspx/kb/942172
;; It seems that the IE7 problem happens either way (`shell-execute' or running
;; directly) -- but it also happens with firefox when using `shell-execute'.
;; One possible solution is to run `ftype http' to find the default browser
;; command, and if it uses `iexplore.exe' then change it to `explorer.exe', and
;; run the resulting command directly. This is described at
;; http://www.tutorials-win.com/IE/Lauching-HTML/
;; But this still fails on Vista, since the problem there is that launching a
;; browser with a file:// URL makes it start a more priviliged process, and
;; doing that drops the fragment again. So the solution that the code below
;; implements is to write and use (via `send-url/contents') a trampoline html
;; that redirects to the actual file and fragment.
(define (send-url/win url)
(if (not (regexp-match? #rx"[#?]" url))
(shell-execute #f url "" (current-directory) 'SW_SHOWNORMAL)
(send-url/contents
(string-append
"<html><head><meta http-equiv=\"refresh\" content=\"0;URL="url"\"></head>"
"<body>Please go <a href=\""url"\">here</a>.</body></html>")
;; starting the browser may take a while, don't remove the file
;; immediately (this means that when used via plt-help, these files are
;; never removed by a timer)
#:delete-at 15)))
;; Process helper
(define (browser-run #:shell [shell? #f] . args)
(define-values (stdout stdin pid stderr control)
(apply values (apply (if shell? process/ports process*/ports)
(open-output-nowhere) #f (current-error-port)
args)))
(close-output-port stdin)
;; this is called from plt-help which will immediately exit when we
;; return, so wait just a little bit in case we'll catch an error
;; starting the browser
(sync/timeout 0.25
(thread (lambda ()
(control 'wait)
(when (eq? 'done-error (control 'status))
(error 'browser-run "process execute failed: ~e" args)))))
(void))