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Diffstat (limited to 'nuttx/lib/lib_fopen.c')
| -rw-r--r-- | nuttx/lib/lib_fopen.c | 232 |
1 files changed, 232 insertions, 0 deletions
diff --git a/nuttx/lib/lib_fopen.c b/nuttx/lib/lib_fopen.c new file mode 100644 index 000000000..0a935ddd2 --- /dev/null +++ b/nuttx/lib/lib_fopen.c @@ -0,0 +1,232 @@ +/************************************************************ + * lib_fopen.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_STREAMS > 0 + +#include <sys/types.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <errno.h> + +#include "lib_internal.h" + +/************************************************************ + * Private Functions + ************************************************************/ + +static int lib_mode2oflags(const char *mode) +{ + int oflags = 0; + if (mode) + { + while(*mode) + { + switch (*mode) + { + /* Open for read access */ + + case 'r' : + if (*(mode + 1) == '+') + { + /* Open for read/write access */ + oflags |= O_RDWR; + mode++; + } + else + { + /* Open for read access */ + oflags |= O_RDOK; + } + break; + + /* Open for write access? */ + + case 'w' : + if (*(mode + 1) == '+') + { + /* Open for write read/access, truncating any existing file */ + oflags |= O_RDWR|O_CREAT|O_TRUNC; + mode++; + } + else + { + /* Open for write access, truncating any existing file */ + oflags |= O_WROK|O_CREAT|O_TRUNC; + } + break; + + /* Open for write/append access? */ + + case 'a' : + if (*(mode + 1) == '+') + { + /* Read from the beginning of the file; write to the end */ + oflags |= O_RDWR|O_CREAT; + mode++; + } + else + { + /* Write to the end of the file */ + oflags |= O_WROK|O_CREAT; + } + break; + + /* Open for binary access? */ + + case 'b' : + default: + break; + } + mode++; + } + } + return oflags; +} + +/************************************************************ + * Public Functions + ************************************************************/ + +struct file_struct *lib_fdopen(int fd, const char *mode, + struct filelist *flist, + struct streamlist *slist) +{ + struct inode *inode = flist->fl_files[fd].f_inode; + FILE *stream; + int oflags = lib_mode2oflags(mode); + int i; + + if (fd < 0 || !flist || !slist) + { + *get_errno_ptr() = EBADF; + return NULL; + } + + /* Make sure that the inode supports the requested access. In + * the case of fdopen, we are not actually creating the file -- in + * particular w and w+ do not truncate the file and any files have + * already been created. + */ + + if (inode_checkflags(inode, oflags) != OK) + { + return NULL; + } + + /* Find an unallocated FILE structure */ + + stream_semtake(slist); + for (i = 0 ; i < CONFIG_NFILE_STREAMS; i++) + { + stream = &slist->sl_streams[i]; + if (stream->fs_filedes < 0) + { + /* Zero the structure */ +#if CONFIG_STDIO_BUFFER_SIZE > 0 + memset(stream, 0, sizeof(FILE)); +#elif CONFIG_NUNGET_CHARS > 0 + stream->fs_nungotten = 0; +#endif + +#if CONFIG_STDIO_BUFFER_SIZE > 0 + /* Initialize the semaphore the manages access to the buffer */ + + (void)sem_init(&stream->fs_sem, 0, 1); + + /* Allocate the IO buffer */ + + stream->fs_bufstart = malloc(CONFIG_STDIO_BUFFER_SIZE); + if (!stream) + { + *get_errno_ptr() = ENOMEM; + return NULL; + } + + /* Set up pointers */ + + stream->fs_bufend = &stream->fs_bufstart[CONFIG_STDIO_BUFFER_SIZE]; + stream->fs_bufpos = stream->fs_bufstart; + stream->fs_bufpos = stream->fs_bufstart; + stream->fs_bufread = stream->fs_bufstart; + stream_semgive(slist); +#endif + /* Save the file description and open flags. Setting the + * file descriptor locks this stream. + */ + + stream->fs_filedes = fd; + stream->fs_oflags = oflags; + + return stream; + } + } + stream_semgive(slist); + return NULL; +} + +FILE *fdopen(int fd, const char *mode) +{ + struct filelist *flist = sched_getfiles(); + struct streamlist *slist = sched_getstreams(); + return lib_fdopen(fd, mode, flist, slist); +} + +FILE *fopen(const char *path, const char *mode) +{ + struct filelist *flist = sched_getfiles(); + struct streamlist *slist = sched_getstreams(); + int oflags = lib_mode2oflags(mode); + int fd = open(path, oflags, 0666); + + FILE *ret = lib_fdopen(fd, mode, flist, slist); + if (!ret) + { + (void)close(fd); + } + return ret; +} + +#endif /* CONFIG_NFILE_STREAMS */ |