racket/collects/readline/rep.rkt
2010-04-27 16:50:15 -06:00

37 lines
1.3 KiB
Racket

;; This is a wrapper around "rep-start.ss" -- use it if we're using a terminal
#lang scheme/base
(require scheme/runtime-path scheme/file)
(define-runtime-path rep-start "rep-start.ss")
(provide install-readline!)
(let ([inp (current-input-port)] [outp (current-output-port)])
(when (and (eq? 'stdin (object-name inp)) (terminal-port? inp))
(dynamic-require rep-start #f)))
(define readline-init-expr
'(require readline/rep))
(define (install-readline!)
(define file (find-system-path 'init-file))
(define (add! msg)
(call-with-output-file* file #:exists 'append
(lambda (o)
(fprintf o "\n;; load readline support ~a\n~s\n"
"(added by `install-readline!')"
readline-init-expr)))
(printf msg file))
(cond [(not (file-exists? file))
(add! "\"~a\" created and readline initialization added.\n")]
[(with-handlers ([exn:fail?
(lambda (exn)
(error 'install-readline!
"trouble reading existing ~e: ~a"
file
(exn-message exn)))])
(not (member readline-init-expr (file->list file))))
(add! "Readline initialization added to \"~a\".\n")]
[else (printf "Readline already installed in \"~a\".\n" file)]))