diff options
Diffstat (limited to 'nuttx/fs/fs_read.c')
-rw-r--r-- | nuttx/fs/fs_read.c | 97 |
1 files changed, 97 insertions, 0 deletions
diff --git a/nuttx/fs/fs_read.c b/nuttx/fs/fs_read.c new file mode 100644 index 0000000000..a092d0db63 --- /dev/null +++ b/nuttx/fs/fs_read.c @@ -0,0 +1,97 @@ +/************************************************************ + * fs_read.c + * + * Copyright (C) 2007 Gregory Nutt. All rights reserved. + * Author: Gregory Nutt <spudmonkey@racsa.co.cr> + * + * 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 Gregory Nutt 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. + * + ************************************************************/ + +/************************************************************ + * Compilation Switches + ************************************************************/ + +/************************************************************ + * Included Files + ************************************************************/ + +#include <nuttx/config.h> + +#if CONFIG_NFILE_DESCRIPTORS >0 + +#include <sys/types.h> +#include <stdio.h> +#include <sched.h> +#include <errno.h> +#include "fs_internal.h" + +/************************************************************ + * Global Functions + ************************************************************/ + +int read(int fd, void *buf, unsigned int nbytes) +{ + struct filelist *list; + int ret = EBADF; + + /* Get the thread-specific file list */ + + list = sched_getfiles(); + if (!list) + { + *get_errno_ptr() = EMFILE; + return ERROR; + } + + /* Were we given a valid file descriptor? */ + + if ((unsigned int)fd < CONFIG_NFILE_DESCRIPTORS) + { + struct file *this_file = &list->fl_files[fd]; + + /* Was this file opened for read access? */ + + if ((this_file->f_oflags & O_RDOK) != 0) + { + struct inode *inode = this_file->f_inode; + + /* Is a driver registered? Does it support the read method? */ + + if (inode && inode->i_ops && inode->i_ops->read) + { + /* Yes, then let it perform the read */ + + ret = (int)inode->i_ops->read(this_file, (char*)buf, (size_t)nbytes); + } + } + } + return ret; +} + +#endif /* CONFIG_NFILE_DESCRIPTORS */ |