kc3-lang/gnulib/lib/dup2.c

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• Hash : dd66a62c
  Author :
  Date : 2009-09-01T09:18:16
  

  fchdir: use more consistent macro convention
  
  * lib/fcntl.in.h (_gl_register_fd): Move declaration to unistd.
  * lib/sys_stat.in.h (rpl_fstat): Declare via make-time
  REPLACE_FCHDIR, rather than relying on config.h macros.
  * lib/unistd.in.h (fchdir): Move all fchdir internal declarations
  inside a single make-time REPLACE_FCHDIR block, rather than using
  the config.h FCHDIR_REPLACEMENT.
  * m4/fchdir.m4 (gl_FUNC_FCHDIR): REPLACE_FCHDIR was already
  AC_SUBST'd, also AC_DEFINE it.  Don't define FCHDIR_REPLACEMENT.
  Manage fstat replacement.
  * m4/sys_stat_h.m4 (gl_SYS_STAT_H_DEFAULTS): Pick up
  REPLACE_FCHDIR.
  * modules/sys_stat (Files): Add m4/unistd_h.m4.
  (Makefile.am): Substitute REPLACE_FCHDIR.
  * lib/close.c (rpl_close): Use REPLACE_FCHDIR, not
  FCHDIR_REPLACEMENT.
  * lib/dup-safer.c (dup_safer): Likewise.
  * lib/dup2.c (rpl_dup2): Likewise.
  * lib/dup3.c (rpl_dup3): Likewise.
  * lib/open.c (rpl_open): Likewise.
  
  Signed-off-by: Eric Blake <ebb9@byu.net>
  

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• lib/dup2.c

• /* Duplicate an open file descriptor to a specified file descriptor.
  
     Copyright (C) 1999, 2004, 2005, 2006, 2007, 2009 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 3 of the License, 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 program.  If not, see <http://www.gnu.org/licenses/>.  */
  
  /* written by Paul Eggert */
  
  #include <config.h>
  
  /* Specification.  */
  #include <unistd.h>
  
  #include <errno.h>
  #include <fcntl.h>
  
  #if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
  /* Get declarations of the Win32 API functions.  */
  # define WIN32_LEAN_AND_MEAN
  # include <windows.h>
  #endif
  
  #if REPLACE_DUP2
  
  # undef dup2
  
  int
  rpl_dup2 (int fd, int desired_fd)
  {
    int result;
  # if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
    /* If fd is closed, mingw hangs on dup2 (fd, fd).  If fd is open,
       dup2 (fd, fd) returns 0, but all further attempts to use fd in
       future dup2 calls will hang.  */
    if (fd == desired_fd)
      {
        if ((HANDLE) _get_osfhandle (fd) == INVALID_HANDLE_VALUE)
          {
            errno = EBADF;
            return -1;
          }
        return fd;
      }
  # endif
    result = dup2 (fd, desired_fd);
  # ifdef __linux__
    /* Correct a Linux return value.
       <http://git.kernel.org/?p=linux/kernel/git/stable/linux-2.6.30.y.git;a=commitdiff;h=2b79bc4f7ebbd5af3c8b867968f9f15602d5f802>
     */
    if (fd == desired_fd && result == (unsigned int) -EBADF)
      {
        errno = EBADF;
        result = -1;
      }
  # endif
    if (result == 0)
      result = desired_fd;
    /* Correct a cygwin 1.5.x errno value.  */
    else if (result == -1 && errno == EMFILE)
      errno = EBADF;
  #if REPLACE_FCHDIR
    if (fd != desired_fd && result == desired_fd)
      result = _gl_register_dup (fd, desired_fd);
  #endif
    return result;
  }
  
  #else /* !REPLACE_DUP2 */
  
  /* On older platforms, dup2 did not exist.  */
  
  # ifndef F_DUPFD
  static int
  dupfd (int fd, int desired_fd)
  {
    int duplicated_fd = dup (fd);
    if (duplicated_fd < 0 || duplicated_fd == desired_fd)
      return duplicated_fd;
    else
      {
        int r = dupfd (fd, desired_fd);
        int e = errno;
        close (duplicated_fd);
        errno = e;
        return r;
      }
  }
  # endif
  
  int
  dup2 (int fd, int desired_fd)
  {
    int result;
    if (fd == desired_fd)
      return fcntl (fd, F_GETFL) < 0 ? -1 : fd;
    close (desired_fd);
  # ifdef F_DUPFD
    result = fcntl (fd, F_DUPFD, desired_fd);
  # else
    result = dupfd (fd, desired_fd);
  # endif
  #if REPLACE_FCHDIR
    if (0 <= result)
      result = _gl_register_dup (fd, desired_fd);
  #endif
    return result;
  }
  #endif /* !REPLACE_DUP2 */
  

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