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Diffstat (limited to 'ice-9/popen.scm')
-rw-r--r-- | ice-9/popen.scm | 205 |
1 files changed, 0 insertions, 205 deletions
diff --git a/ice-9/popen.scm b/ice-9/popen.scm deleted file mode 100644 index 2a3bdd605..000000000 --- a/ice-9/popen.scm +++ /dev/null @@ -1,205 +0,0 @@ -;; popen emulation, for non-stdio based ports. - -;;;; Copyright (C) 1998, 1999, 2000, 2001 Free Software Foundation, Inc. -;;;; -;;;; This program is free software; you can redistribute it and/or modify -;;;; it under the terms of the GNU General Public License as published by -;;;; the Free Software Foundation; either version 2, or (at your option) -;;;; any later version. -;;;; -;;;; This program 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 General Public License for more details. -;;;; -;;;; You should have received a copy of the GNU General Public License -;;;; along with this software; see the file COPYING. If not, write to -;;;; the Free Software Foundation, Inc., 59 Temple Place, Suite 330, -;;;; Boston, MA 02111-1307 USA -;;;; -;;;; As a special exception, the Free Software Foundation gives permission -;;;; for additional uses of the text contained in its release of GUILE. -;;;; -;;;; The exception is that, if you link the GUILE library with other files -;;;; to produce an executable, this does not by itself cause the -;;;; resulting executable to be covered by the GNU General Public License. -;;;; Your use of that executable is in no way restricted on account of -;;;; linking the GUILE library code into it. -;;;; -;;;; This exception does not however invalidate any other reasons why -;;;; the executable file might be covered by the GNU General Public License. -;;;; -;;;; This exception applies only to the code released by the -;;;; Free Software Foundation under the name GUILE. If you copy -;;;; code from other Free Software Foundation releases into a copy of -;;;; GUILE, as the General Public License permits, the exception does -;;;; not apply to the code that you add in this way. To avoid misleading -;;;; anyone as to the status of such modified files, you must delete -;;;; this exception notice from them. -;;;; -;;;; If you write modifications of your own for GUILE, it is your choice -;;;; whether to permit this exception to apply to your modifications. -;;;; If you do not wish that, delete this exception notice. -;;;; - -(define-module (ice-9 popen) - :export (port/pid-table open-pipe close-pipe open-input-pipe - open-output-pipe)) - -;; (define-module (guile popen) -;; :use-module (guile posix)) - -;; a guardian to ensure the cleanup is done correctly when -;; an open pipe is gc'd or a close-port is used. -(define pipe-guardian (make-guardian)) - -;; a weak hash-table to store the process ids. -(define port/pid-table (make-weak-key-hash-table 31)) - -(define (ensure-fdes port mode) - (or (false-if-exception (fileno port)) - (open-fdes *null-device* mode))) - -;; run a process connected to an input or output port. -;; mode: OPEN_READ or OPEN_WRITE. -;; returns port/pid pair. -(define (open-process mode prog . args) - (let ((p (pipe)) - (reading (string=? mode OPEN_READ))) - (setvbuf (cdr p) _IONBF) - (let ((pid (primitive-fork))) - (cond ((= pid 0) - ;; child - (set-batch-mode?! #t) - - ;; select the three file descriptors to be used as - ;; standard descriptors 0, 1, 2 for the new process. one - ;; is the pipe to the parent, the other two are taken - ;; from the current Scheme input/output/error ports if - ;; possible. - - (let ((input-fdes (if reading - (ensure-fdes (current-input-port) - O_RDONLY) - (fileno (car p)))) - (output-fdes (if reading - (fileno (cdr p)) - (ensure-fdes (current-output-port) - O_WRONLY))) - (error-fdes (ensure-fdes (current-error-port) - O_WRONLY))) - - ;; close all file descriptors in ports inherited from - ;; the parent except for the three selected above. - ;; this is to avoid causing problems for other pipes in - ;; the parent. - - ;; use low-level system calls, not close-port or the - ;; scsh routines, to avoid side-effects such as - ;; flushing port buffers or evicting ports. - - (port-for-each (lambda (pt-entry) - (false-if-exception - (let ((pt-fileno (fileno pt-entry))) - (if (not (or (= pt-fileno input-fdes) - (= pt-fileno output-fdes) - (= pt-fileno error-fdes))) - (close-fdes pt-fileno)))))) - - ;; copy the three selected descriptors to the standard - ;; descriptors 0, 1, 2. note that it's possible that - ;; output-fdes or input-fdes is equal to error-fdes. - - (cond ((not (= input-fdes 0)) - (if (= output-fdes 0) - (set! output-fdes (dup->fdes 0))) - (if (= error-fdes 0) - (set! error-fdes (dup->fdes 0))) - (dup2 input-fdes 0))) - - (cond ((not (= output-fdes 1)) - (if (= error-fdes 1) - (set! error-fdes (dup->fdes 1))) - (dup2 output-fdes 1))) - - (dup2 error-fdes 2) - - (apply execlp prog prog args))) - - (else - ;; parent - (if reading - (close-port (cdr p)) - (close-port (car p))) - (cons (if reading - (car p) - (cdr p)) - pid)))))) - -(define (open-pipe command mode) - "Executes the shell command @var{command} (a string) in a subprocess. -A pipe to the process is created and returned. @var{modes} specifies -whether an input or output pipe to the process is created: it should -be the value of @code{OPEN_READ} or @code{OPEN_WRITE}." - (let* ((port/pid (open-process mode "/bin/sh" "-c" command)) - (port (car port/pid))) - (pipe-guardian port) - (hashq-set! port/pid-table port (cdr port/pid)) - port)) - -(define (fetch-pid port) - (let ((pid (hashq-ref port/pid-table port))) - (hashq-remove! port/pid-table port) - pid)) - -(define (close-process port/pid) - (close-port (car port/pid)) - (cdr (waitpid (cdr port/pid)))) - -;; for the background cleanup handler: just clean up without reporting -;; errors. also avoids blocking the process: if the child isn't ready -;; to be collected, puts it back into the guardian's live list so it -;; can be tried again the next time the cleanup runs. -(define (close-process-quietly port/pid) - (catch 'system-error - (lambda () - (close-port (car port/pid))) - (lambda args #f)) - (catch 'system-error - (lambda () - (let ((pid/status (waitpid (cdr port/pid) WNOHANG))) - (cond ((= (car pid/status) 0) - ;; not ready for collection - (pipe-guardian (car port/pid)) - (hashq-set! port/pid-table - (car port/pid) (cdr port/pid)))))) - (lambda args #f))) - -(define (close-pipe p) - "Closes the pipe created by @code{open-pipe}, then waits for the process -to terminate and returns its status value, @xref{Processes, waitpid}, for -information on how to interpret this value." - (let ((pid (fetch-pid p))) - (if (not pid) - (error "close-pipe: pipe not in table")) - (close-process (cons p pid)))) - -(define reap-pipes - (lambda () - (let loop ((p (pipe-guardian))) - (cond (p - ;; maybe removed already by close-pipe. - (let ((pid (fetch-pid p))) - (if pid - (close-process-quietly (cons p pid)))) - (loop (pipe-guardian))))))) - -(add-hook! after-gc-hook reap-pipes) - -(define (open-input-pipe command) - "Equivalent to @code{open-pipe} with mode @code{OPEN_READ}" - (open-pipe command OPEN_READ)) - -(define (open-output-pipe command) - "Equivalent to @code{open-pipe} with mode @code{OPEN_WRITE}" - (open-pipe command OPEN_WRITE)) |