diff options
Diffstat (limited to 'gnu/build')
| -rw-r--r-- | gnu/build/marionette.scm | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/gnu/build/marionette.scm b/gnu/build/marionette.scm index 70b737fc57..8070b6b439 100644 --- a/gnu/build/marionette.scm +++ b/gnu/build/marionette.scm @@ -21,10 +21,12 @@ #:use-module (srfi srfi-26) #:use-module (rnrs io ports) #:use-module (ice-9 match) + #:use-module (ice-9 popen) #:export (marionette? make-marionette marionette-eval marionette-control + marionette-screen-text %qwerty-us-keystrokes marionette-type)) @@ -171,6 +173,37 @@ pcsys_monitor\")." (newline monitor) (wait-for-monitor-prompt monitor)))) +(define* (marionette-screen-text marionette + #:key + (ocrad "ocrad")) + "Take a screenshot of MARIONETTE, perform optical character +recognition (OCR), and return the text read from the screen as a string. Do +this by invoking OCRAD (file name for GNU Ocrad's command)" + (define (random-file-name) + (string-append "/tmp/marionette-screenshot-" + (number->string (random (expt 2 32)) 16) + ".ppm")) + + (let ((image (random-file-name))) + (dynamic-wind + (const #t) + (lambda () + (marionette-control (string-append "screendump " image) + marionette) + + ;; Tell Ocrad to invert the image colors (make it black on white) and + ;; to scale the image up, which significantly improves the quality of + ;; the result. In spite of this, be aware that OCR confuses "y" and + ;; "V" and sometimes erroneously introduces white space. + (let* ((pipe (open-pipe* OPEN_READ ocrad + "-i" "-s" "10" image)) + (text (get-string-all pipe))) + (unless (zero? (close-pipe pipe)) + (error "'ocrad' failed" ocrad)) + text)) + (lambda () + (false-if-exception (delete-file image)))))) + (define %qwerty-us-keystrokes ;; Maps "special" characters to their keystrokes. '((#\newline . "ret") |