diff options
Diffstat (limited to 'nuttx/fs/fs_filedup.c')
-rw-r--r-- | nuttx/fs/fs_filedup.c | 122 |
1 files changed, 122 insertions, 0 deletions
diff --git a/nuttx/fs/fs_filedup.c b/nuttx/fs/fs_filedup.c new file mode 100644 index 000000000..b7eeb7add --- /dev/null +++ b/nuttx/fs/fs_filedup.c @@ -0,0 +1,122 @@ +/**************************************************************************** + * fs/fs_filedup.c + * + * Copyright (C) 2007-2009, 2011-2012 Gregory Nutt. All rights reserved. + * Author: Gregory Nutt <gnutt@nuttx.org> + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * 3. Neither the name NuttX nor the names of its contributors may be + * used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE + * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, + * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS + * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED + * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN + * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + * + ****************************************************************************/ + +/**************************************************************************** + * Included Files + ****************************************************************************/ + +#include <nuttx/config.h> + +#include <sched.h> +#include <errno.h> + +#include <nuttx/fs/fs.h> + +#include "fs_internal.h" + +#if CONFIG_NFILE_DESCRIPTORS > 0 + +/**************************************************************************** + * Pre-processor Definitions + ****************************************************************************/ + +#define DUP_ISOPEN(fd, list) \ + ((unsigned int)fd < CONFIG_NFILE_DESCRIPTORS && \ + list->fl_files[fd].f_inode != NULL) + +/**************************************************************************** + * Private Functions + ****************************************************************************/ + +/**************************************************************************** + * Global Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: file_dup OR dup + * + * Description: + * Clone a file descriptor 'fd' to an arbitray descriptor number (any value + * greater than or equal to 'minfd'). If socket descriptors are + * implemented, then this is called by dup() for the case of file + * descriptors. If socket descriptors are not implemented, then this + * function IS dup(). + * + ****************************************************************************/ + +int file_dup(int fildes, int minfd) +{ + FAR struct filelist *list; + int fildes2; + + /* Get the thread-specific file list */ + + list = sched_getfiles(); + if (!list) + { + set_errno(EMFILE); + return ERROR; + } + + /* Verify that fildes is a valid, open file descriptor */ + + if (!DUP_ISOPEN(fildes, list)) + { + set_errno(EBADF); + return ERROR; + } + + /* Increment the reference count on the contained inode */ + + inode_addref(list->fl_files[fildes].f_inode); + + /* Then allocate a new file descriptor for the inode */ + + fildes2 = files_allocate(list->fl_files[fildes].f_inode, + list->fl_files[fildes].f_oflags, + list->fl_files[fildes].f_pos, + minfd); + if (fildes2 < 0) + { + set_errno(EMFILE); + inode_release(list->fl_files[fildes].f_inode); + return ERROR; + } + + return fildes2; +} + +#endif /* CONFIG_NFILE_DESCRIPTORS > 0 */ + |