syndicate-rkt/syndicate-examples/tcp-client.rkt

42 lines
1.9 KiB
Racket

#lang syndicate
;;; SPDX-License-Identifier: LGPL-3.0-or-later
;;; SPDX-FileCopyrightText: Copyright © 2021 Tony Garnock-Jones <tonyg@leastfixedpoint.com>
(module+ main
(require racket/cmdline)
(require (only-in racket/port read-line-evt))
(require syndicate/drivers/tcp)
(require syndicate/drivers/racket-event)
(define host "127.0.0.1")
(define port 5999)
(command-line #:once-each
[("--host" "-H") hostname "Set hostname to connect to"
(set! host hostname)]
[("--port" "-p") port-number "Set port number to connect to"
(set! port (string->number port-number))])
(standard-actor-system (ds)
(with-services [syndicate/drivers/racket-event]
(establish-connection
ds (TcpRemote host port)
#:initial-mode (Mode-lines (LineMode-lf))
#:on-connect (lambda (source sink)
(at ds
(on (message (RacketEvent (read-line-evt (current-input-port)) $vs))
(match (car vs)
[(? eof-object?) (stop-current-facet (log-info "EOF on stdin."))]
[line (send-line sink line)]))))
#:on-rejected (lambda (message) (stop-current-facet (log-error "~a" message)))
#:on-disconnect (lambda () (stop-current-facet (log-info "Disconnected")))
#:on-data (lambda (line _mode)
;; \e7 DECSC, save cursor position
;; \n\e[A Force a new line if at end of screen, then back up; effect of \r
;; \e[L Insert a line here, pushing the current line's contents down one
;; ~a Placeholder for the incoming line
;; \e8 DECRC, Restore cursor - it will be one line too high
;; \e[B Correct for the one line to high
(printf "\e7\n\e[A\e[L~a\e8\e[B" line)
(flush-output))))))