guile/test-suite/tests/popen.test

;;;; popen.test --- exercise ice-9/popen.scm      -*- scheme -*-
;;;;
;;;; Copyright 2003, 2006 Free Software Foundation, Inc.
;;;;
;;;; This library is free software; you can redistribute it and/or
;;;; modify it under the terms of the GNU Lesser General Public
;;;; License as published by the Free Software Foundation; either
;;;; version 2.1 of the License, or (at your option) any later version.
;;;; 
;;;; This library is distributed in the hope that it will be useful,
;;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
;;;; Lesser General Public License for more details.
;;;; 
;;;; You should have received a copy of the GNU Lesser General Public
;;;; License along with this library; if not, write to the Free Software
;;;; Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

(define-module (test-suite test-ice-9-popen)
  #:use-module (test-suite lib)
  #:use-module (ice-9 popen))


;; read from PORT until eof is reached, return what's read as a string
(define (read-string-to-eof port)
  (do ((lst '() (cons c lst))
       (c (read-char port) (read-char port)))
      ((eof-object? c)
       (list->string (reverse! lst)))))

;; call (THUNK), with SIGPIPE set to SIG_IGN so that an EPIPE error is
;; generated rather than a SIGPIPE signal
(define (with-epipe thunk)
  (dynamic-wind
      (lambda ()
	(sigaction SIGPIPE SIG_IGN))
      thunk
      restore-signals))


;;
;; open-input-pipe
;;

(with-test-prefix "open-input-pipe"
  
  (pass-if-exception "no args" exception:wrong-num-args
    (open-input-pipe))
  
  (pass-if "port?"
    (port? (open-input-pipe "echo hello")))
  
  (pass-if "echo hello"
    (string=? "hello\n" (read-string-to-eof (open-input-pipe "echo hello"))))
  
  ;; exercise file descriptor setups when stdin is the same as stderr  
  (pass-if "stdin==stderr"
    (let ((port (open-file "/dev/null" "r+")))
      (with-input-from-port port
	(lambda ()
	  (with-error-to-port port
	    (lambda ()
	      (open-input-pipe "echo hello"))))))
    #t)
  
  ;; exercise file descriptor setups when stdout is the same as stderr  
  (pass-if "stdout==stderr"
    (let ((port (open-file "/dev/null" "r+")))
      (with-output-to-port port
	(lambda ()
	  (with-error-to-port port
	    (lambda ()
	      (open-input-pipe "echo hello"))))))
    #t)
  
  (pass-if "open-input-pipe process gets (current-input-port) as stdin"
    (let* ((p2c (pipe))
           (port (with-input-from-port (car p2c)
                   (lambda ()
                     (open-input-pipe "read line && echo $line")))))
      (display "hello\n" (cdr p2c))
      (force-output (cdr p2c))
      (let ((result (eq? (read port) 'hello)))
	(close-port (cdr p2c))
	(close-pipe port)
	result)))

  ;; After the child closes stdout (which it indicates here by writing
  ;; "closed" to stderr), the parent should see eof.  In Guile 1.6.4
  ;; and earlier a duplicate of stdout existed in the child, meaning
  ;; eof was not seen.
  ;;
  ;; Note that the objective here is to test that the parent sees EOF
  ;; while the child is still alive.  (It is obvious that the parent
  ;; must see EOF once the child has died.)  The use of the `p2c'
  ;; pipe, and `echo closed' and `read' in the child, allows us to be
  ;; sure that we are testing what the parent sees at a point where
  ;; the child has closed stdout but is still alive.
  (pass-if "no duplicate"
    (let* ((c2p (pipe))
	   (p2c (pipe))
	   (port (with-error-to-port (cdr c2p)
		   (lambda ()
		     (with-input-from-port (car p2c)
		       (lambda ()
			 (open-input-pipe
			  "exec 1>/dev/null; echo closed 1>&2; exec 2>/dev/null; read")))))))
      (close-port (cdr c2p))   ;; write side
      (let ((result (eof-object? (read-char port))))
	(display "hello!\n" (cdr p2c))
	(force-output (cdr p2c))
	(close-pipe port)
	result)))

  )

;;
;; open-output-pipe
;;

(with-test-prefix "open-output-pipe"
  
  (pass-if-exception "no args" exception:wrong-num-args
    (open-output-pipe))
  
  (pass-if "port?"
    (port? (open-output-pipe "exit 0")))
  
  ;; exercise file descriptor setups when stdin is the same as stderr  
  (pass-if "stdin==stderr"
    (let ((port (open-file "/dev/null" "r+")))
      (with-input-from-port port
	(lambda ()
	  (with-error-to-port port
	    (lambda ()
	      (open-output-pipe "exit 0"))))))
    #t)
  
  ;; exercise file descriptor setups when stdout is the same as stderr
  (pass-if "stdout==stderr"
    (let ((port (open-file "/dev/null" "r+")))
      (with-output-to-port port
	(lambda ()
	  (with-error-to-port port
	    (lambda ()
	      (open-output-pipe "exit 0"))))))
    #t)
  
  ;; After the child closes stdin (which it indicates here by writing
  ;; "closed" to stderr), the parent should see a broken pipe.  We
  ;; setup to see this as EPIPE (rather than SIGPIPE).  In Guile 1.6.4
  ;; and earlier a duplicate of stdin existed in the child, preventing
  ;; the broken pipe occurring.
  ;;
  ;; Note that the objective here is to test that the parent sees a
  ;; broken pipe while the child is still alive.  (It is obvious that
  ;; the parent will see a broken pipe once the child has died.)  The
  ;; use of the `c2p' pipe, and the repeated `echo closed' in the
  ;; child, allows us to be sure that we are testing what the parent
  ;; sees at a point where the child has closed stdin but is still
  ;; alive.
  ;;
  ;; Note that `with-epipe' must apply only to the parent and not to
  ;; the child process; we rely on the child getting SIGPIPE, to
  ;; terminate it (and avoid leaving a zombie).
  (pass-if "no duplicate"
    (let* ((c2p (pipe))
	   (port (with-error-to-port (cdr c2p)
		   (lambda ()
		     (open-output-pipe
		      "exec 0</dev/null; while true; do echo closed 1>&2; done")))))
      (close-port (cdr c2p))   ;; write side
      (with-epipe
       (lambda ()
	 (let ((result
		(and (char? (read-char (car c2p))) ;; wait for child to do its thing
		     (catch 'system-error
			    (lambda ()
			      (write-char #\x port)
			      (force-output port)
			      #f)
			    (lambda (key name fmt args errno-list)
			      (= (car errno-list) EPIPE))))))
	   ;; Now close our reading end of the pipe.  This should give
	   ;; the child a broken pipe and so allow it to exit.
	   (close-port (car c2p))
	   (close-pipe port)
	   result)))))

  )

;;
;; close-pipe
;;

(with-test-prefix "close-pipe"
  
  (pass-if-exception "no args" exception:wrong-num-args
    (close-pipe))
  
  (pass-if "exit 0"
    (let ((st (close-pipe (open-output-pipe "exit 0"))))
      (and (status:exit-val st)
	   (= 0 (status:exit-val st)))))
  
  (pass-if "exit 1"
    (let ((st (close-pipe (open-output-pipe "exit 1"))))
      (and (status:exit-val st)
	   (= 1 (status:exit-val st))))))