/****************************************************************************
* lib/stdio/lib_fgets.c
*
* Copyright (C) 2007-2008, 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 <stdbool.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <ctype.h>
#include <debug.h>
/****************************************************************************
* Definitions
****************************************************************************/
/* Some environments may return CR as end-of-line, others LF, and others
* both. The logic here assumes either but not both.
*/
#undef CONFIG_EOL_IS_CR
#undef CONFIG_EOL_IS_LF
#undef CONFIG_EOL_IS_BOTH_CRLF
#define CONFIG_EOL_IS_EITHER_CRLF 1
/****************************************************************************
* Private Type Declarations
****************************************************************************/
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
/****************************************************************************
* Public Data
****************************************************************************/
/****************************************************************************
* Private Data
****************************************************************************/
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Global Functions
****************************************************************************/
/****************************************************************************
* Name: fgets
*
* Description:
* fgets() reads in at most one less than 'buflen' characters from stream
* and stores them into the buffer pointed to by 'buf'. Reading stops after
* an EOF or a newline. If a newline is read, it is stored into the
* buffer. A null terminator is stored after the last character in the
* buffer.
*
**************************************************************************/
char *fgets(FAR char *buf, int buflen, FILE *stream)
{
int nch = 0;
/* Sanity checks */
if (!stream || !buf || buflen < 1 || stream->fs_filedes < 0)
{
return NULL;
}
if (buflen < 2)
{
*buf = '\0';
return buf;
}
/* Read characters until we have a full line. On each the loop we must
* be assured that there are two free bytes in the line buffer: One for
* the next character and one for the null terminator.
*/
for(;;)
{
/* Get the next character */
int ch = fgetc(stream);
/* Check for end-of-line. This is tricky only in that some
* environments may return CR as end-of-line, others LF, and
* others both.
*/
#if defined(CONFIG_EOL_IS_LF) || defined(CONFIG_EOL_IS_BOTH_CRLF)
if (ch == '\n')
#elif defined(CONFIG_EOL_IS_CR)
if (ch == '\r')
#elif CONFIG_EOL_IS_EITHER_CRLF
if (ch == '\n' || ch == '\r')
#endif
{
/* The newline is stored in the buffer along with the null
* terminator.
*/
buf[nch++] = '\n';
buf[nch] = '\0';
return buf;
}
/* Check for end-of-file */
else if (ch == EOF)
{
/* End of file with no data? */
if (!nch)
{
/* Yes.. return NULL as the end of file mark */
return NULL;
}
else
{
/* Terminate the line */
buf[nch] = '\0';
return buf;
}
}
/* Otherwise, check if the character is printable and, if so, put the
* character in the line buffer
*/
else if (isprint(ch))
{
buf[nch++] = ch;
/* Check if there is room for another character and the line's
* null terminator. If not then we have to end the line now.
*/
if (nch + 1 >= buflen)
{
buf[nch] = '\0';
return buf;
}
}
}
}
