guile/test-suite/tests/popen.test

;;;; popen.test --- exercise ice-9/popen.scm      -*- scheme -*-
;;;;
;;;; Copyright 2003, 2006, 2010, 2011, 2013, 2014 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 3 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))

;; 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))

(define-syntax-rule (if-supported body ...)
  (begin body ...))

(if-supported
 (use-modules (ice-9 popen))


 ;;
 ;; 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
                           (format #f "exec 1>~a; echo closed 1>&2; \
exec 2>~a; read REPLY"
                                   %null-device %null-device))))))))
       (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
                       (string-append "exec guile --no-auto-compile -s \""
                                      (getenv "TEST_SUITE_DIR")
                                      "/tests/popen-child.scm\""))))))
       (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)))))))