300 lines
8.5 KiB
C
300 lines
8.5 KiB
C
/****************************************************************************
|
|
* libc/stdio/lib_fopen.c
|
|
*
|
|
* Copyright (C) 2007-2012 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 <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <unistd.h>
|
|
#include <fcntl.h>
|
|
#include <string.h>
|
|
#include <errno.h>
|
|
|
|
#include "lib_internal.h"
|
|
|
|
/****************************************************************************
|
|
* Pre-processor Definitions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Private Types
|
|
****************************************************************************/
|
|
|
|
enum open_mode_e
|
|
{
|
|
MODE_NONE = 0, /* No access mode determined */
|
|
MODE_R, /* "r" or "rb" open for reading */
|
|
MODE_W, /* "w" or "wb" open for writing, truncating or creating file */
|
|
MODE_A, /* "a" or "ab" open for writing, appending to file */
|
|
MODE_RPLUS, /* "r+", "rb+", or "r+b" open for update (reading and writing) */
|
|
MODE_WPLUS, /* "w+", "wb+", or "w+b" open for update, truncating or creating file */
|
|
MODE_APLUS /* "a+", "ab+", or "a+b" open for update, appending to file */
|
|
};
|
|
|
|
/****************************************************************************
|
|
* Private Functions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Name: lib_mode2oflags
|
|
****************************************************************************/
|
|
|
|
static int lib_mode2oflags(FAR const char *mode)
|
|
{
|
|
enum open_mode_e state;
|
|
int oflags;
|
|
|
|
/* Verify that a mode string was provided. No error is */
|
|
|
|
if (!mode)
|
|
{
|
|
goto errout;
|
|
}
|
|
|
|
/* Parse the mode string to determine the corresponding open flags */
|
|
|
|
state = MODE_NONE;
|
|
oflags = 0;
|
|
|
|
for (; *mode; mode++)
|
|
{
|
|
switch (*mode)
|
|
{
|
|
/* Open for read access ("r", "r[+]", "r[b]", "r[b+]", or "r[+b]") */
|
|
|
|
case 'r' :
|
|
if (state == MODE_NONE)
|
|
{
|
|
/* Open for read access */
|
|
|
|
oflags = O_RDOK;
|
|
state = MODE_R;
|
|
}
|
|
else
|
|
{
|
|
goto errout;
|
|
}
|
|
break;
|
|
|
|
/* Open for write access ("w", "w[+]", "w[b]", "w[b+]", or "w[+b]") */
|
|
|
|
case 'w' :
|
|
if (state == MODE_NONE)
|
|
{
|
|
/* Open for write access, truncating any existing file */
|
|
|
|
oflags = O_WROK|O_CREAT|O_TRUNC;
|
|
state = MODE_W;
|
|
}
|
|
else
|
|
{
|
|
goto errout;
|
|
}
|
|
break;
|
|
|
|
/* Open for write/append access ("a", "a[+]", "a[b]", "a[b+]", or "a[+b]") */
|
|
|
|
case 'a' :
|
|
if (state == MODE_NONE)
|
|
{
|
|
/* Write to the end of the file */
|
|
|
|
oflags = O_WROK|O_CREAT|O_APPEND;
|
|
state = MODE_A;
|
|
}
|
|
else
|
|
{
|
|
goto errout;
|
|
}
|
|
break;
|
|
|
|
/* Open for update access ("[r]+", "[rb]+]", "[r]+[b]", "[w]+",
|
|
* "[wb]+]", "[w]+[b]", "[a]+", "[ab]+]", "[a]+[b]")
|
|
*/
|
|
|
|
case '+' :
|
|
switch (state)
|
|
{
|
|
case MODE_R:
|
|
{
|
|
/* Retain any binary mode selection */
|
|
|
|
oflags &= O_BINARY;
|
|
|
|
/* Open for read/write access */
|
|
|
|
oflags |= O_RDWR;
|
|
state = MODE_RPLUS;
|
|
}
|
|
break;
|
|
|
|
case MODE_W:
|
|
{
|
|
/* Retain any binary mode selection */
|
|
|
|
oflags &= O_BINARY;
|
|
|
|
/* Open for write read/access, truncating any existing file */
|
|
|
|
oflags |= O_RDWR|O_CREAT|O_TRUNC;
|
|
state = MODE_WPLUS;
|
|
}
|
|
break;
|
|
|
|
case MODE_A:
|
|
{
|
|
/* Retain any binary mode selection */
|
|
|
|
oflags &= O_BINARY;
|
|
|
|
/* Read from the beginning of the file; write to the end */
|
|
|
|
oflags |= O_RDWR|O_CREAT|O_APPEND;
|
|
state = MODE_APLUS;
|
|
}
|
|
break;
|
|
|
|
default:
|
|
goto errout;
|
|
break;
|
|
}
|
|
break;
|
|
|
|
/* Open for binary access ("[r]b", "[r]b[+]", "[r+]b", "[w]b",
|
|
* "[w]b[+]", "[w+]b", "[a]b", "[a]b[+]", "[a+]b")
|
|
*/
|
|
|
|
case 'b' :
|
|
if (state != MODE_NONE)
|
|
{
|
|
/* The file is opened in binary mode */
|
|
|
|
oflags |= O_BINARY;
|
|
}
|
|
else
|
|
{
|
|
goto errout;
|
|
}
|
|
break;
|
|
|
|
/* Unrecognized or unsupported mode */
|
|
|
|
default:
|
|
goto errout;
|
|
break;
|
|
}
|
|
}
|
|
|
|
return oflags;
|
|
|
|
/* Both fopen and fdopen should fail with errno == EINVAL if the mode
|
|
* string is invalid.
|
|
*/
|
|
|
|
errout:
|
|
set_errno(EINVAL);
|
|
return ERROR;
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Public Functions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Name: fdopen
|
|
****************************************************************************/
|
|
|
|
FAR FILE *fdopen(int fd, FAR const char *mode)
|
|
{
|
|
FAR FILE *ret = NULL;
|
|
int oflags;
|
|
|
|
/* Map the open mode string to open flags */
|
|
|
|
oflags = lib_mode2oflags(mode);
|
|
if (oflags >= 0)
|
|
{
|
|
ret = fs_fdopen(fd, oflags, NULL);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Name: fopen
|
|
****************************************************************************/
|
|
|
|
FAR FILE *fopen(FAR const char *path, FAR const char *mode)
|
|
{
|
|
FAR FILE *ret = NULL;
|
|
int oflags;
|
|
int fd;
|
|
|
|
/* Map the open mode string to open flags */
|
|
|
|
oflags = lib_mode2oflags(mode);
|
|
if (oflags < 0)
|
|
{
|
|
return NULL;
|
|
}
|
|
|
|
/* Open the file */
|
|
|
|
fd = open(path, oflags, 0666);
|
|
|
|
/* If the open was successful, then fdopen() the fil using the file
|
|
* desciptor returned by open. If open failed, then just return the
|
|
* NULL stream -- open() has already set the errno.
|
|
*/
|
|
|
|
if (fd >= 0)
|
|
{
|
|
ret = fs_fdopen(fd, oflags, NULL);
|
|
if (!ret)
|
|
{
|
|
/* Don't forget to close the file descriptor if any other
|
|
* failures are reported by fdopen().
|
|
*/
|
|
|
|
(void)close(fd);
|
|
}
|
|
}
|
|
return ret;
|
|
}
|