9ab11697a8
git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@275 42af7a65-404d-4744-a932-0658087f49c3
323 lines
8.8 KiB
C
323 lines
8.8 KiB
C
/************************************************************
|
|
* lib_fgets.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.
|
|
*
|
|
************************************************************/
|
|
|
|
/************************************************************
|
|
* Included Files
|
|
************************************************************/
|
|
|
|
#include <nuttx/config.h>
|
|
#include <stdio.h>
|
|
#include <unistd.h>
|
|
#include <string.h>
|
|
#include <ctype.h>
|
|
#include <debug.h>
|
|
|
|
/************************************************************
|
|
* Definitions
|
|
************************************************************/
|
|
|
|
/* In some systems, the underlying serial logic may
|
|
* automatically echo characters back to the console. We
|
|
* will assume that that is not the case here
|
|
*/
|
|
|
|
#define CONFIG_FGETS_ECHO 1
|
|
|
|
/* 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
|
|
************************************************************/
|
|
|
|
/* <esc>[K is the VT100 command erases to the end of the line. */
|
|
|
|
static const char g_erasetoeol[] = "\033[K";
|
|
|
|
/************************************************************
|
|
* Private Functions
|
|
************************************************************/
|
|
|
|
/************************************************************
|
|
* Name: _lib_rawgetc
|
|
************************************************************/
|
|
|
|
static inline int _lib_rawgetc(int fd)
|
|
{
|
|
char buffer;
|
|
(void)read(fd, &buffer, 1);
|
|
return buffer;
|
|
}
|
|
|
|
/************************************************************
|
|
* Name: _lib_consoleputc
|
|
************************************************************/
|
|
|
|
#ifdef CONFIG_FGETS_ECHO
|
|
static inline void _lib_consoleputc(int ch)
|
|
{
|
|
char buffer = ch;
|
|
(void)write(1, &buffer, 1);
|
|
}
|
|
#endif
|
|
|
|
/************************************************************
|
|
* Name: _lib_consoleputs
|
|
************************************************************/
|
|
|
|
#ifdef CONFIG_FGETS_ECHO
|
|
static inline void _lib_consoleputs(const char *s)
|
|
{
|
|
(void)write(1, s, strlen(s));
|
|
}
|
|
#endif
|
|
|
|
/************************************************************
|
|
* Global Functions
|
|
************************************************************/
|
|
|
|
/************************************************************
|
|
* Name: fgets
|
|
*
|
|
* Description:
|
|
* fgets() reads in at most one less than 'n' characters
|
|
* from stream and stores them into the buffer pointed to
|
|
* by 's'. 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.
|
|
*
|
|
* Assumptions:
|
|
* If the stream corresponds to stdin (fd=0) this version
|
|
* will assume that we are reading characters from a
|
|
* VT100 console and that stdout (fd=1) is also available.
|
|
* This will not work well if fd=0 corresponds to a raw
|
|
* byte steam.
|
|
*
|
|
**********************************************************/
|
|
|
|
char *fgets(FAR char *s, int n, FILE *stream)
|
|
{
|
|
#ifdef CONFIG_FGETS_ECHO
|
|
boolean console;
|
|
#endif
|
|
int escape = 0;
|
|
int nch = 0;
|
|
|
|
/* Sanity checks */
|
|
|
|
if (!stream || !s || n < 1 || stream->fs_filedes < 0)
|
|
{
|
|
return NULL;
|
|
}
|
|
|
|
if (n < 2)
|
|
{
|
|
*s = '\0';
|
|
return s;
|
|
}
|
|
|
|
/* Check if the stream is stdin */
|
|
|
|
#ifdef CONFIG_FGETS_ECHO
|
|
console = (stream->fs_filedes == 0);
|
|
|
|
/* <esc>[K is the VT100 command that erases to the end of the line. */
|
|
|
|
if (console)
|
|
{
|
|
_lib_consoleputs(g_erasetoeol);
|
|
}
|
|
#endif
|
|
|
|
/* 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 = _lib_rawgetc(stream->fs_filedes);
|
|
|
|
/* Are we processing a VT100 escape sequence */
|
|
|
|
if (escape)
|
|
{
|
|
/* Yes, is it an <esc>[, 3 byte sequence */
|
|
|
|
if (ch != 0x5b || escape == 2)
|
|
{
|
|
/* We are finished with the escape sequence */
|
|
|
|
escape = 0;
|
|
ch = 'a';
|
|
}
|
|
else
|
|
{
|
|
/* The next character is the end of a 3-byte sequence.
|
|
* NOTE: Some of the <esc>[ sequences are longer than
|
|
* 3-bytes, but I have not encountered any in normal use
|
|
* yet and, so, have not provided the decoding logic.
|
|
*/
|
|
|
|
escape = 2;
|
|
}
|
|
}
|
|
|
|
/* Check for backspace */
|
|
|
|
else if (ch == 0x08)
|
|
{
|
|
/* Eliminate that last character in the buffer. */
|
|
|
|
if (nch > 0)
|
|
{
|
|
nch--;
|
|
|
|
#ifdef CONFIG_FGETS_ECHO
|
|
if (console)
|
|
{
|
|
/* Echo the backspace character on the console */
|
|
|
|
_lib_consoleputc(ch);
|
|
_lib_consoleputs(g_erasetoeol);
|
|
}
|
|
#endif
|
|
}
|
|
}
|
|
|
|
/* Check for the beginning of a VT100 escape sequence */
|
|
|
|
else if (console && ch == 0x1b)
|
|
{
|
|
/* The next character is escaped */
|
|
|
|
escape = 1;
|
|
}
|
|
|
|
/* 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)
|
|
else if (ch == '\n')
|
|
#elif defined(CONFIG_EOL_IS_CR)
|
|
else if (ch == '\r')
|
|
#elif CONFIG_EOL_IS_EITHER_CRLF
|
|
else if (ch == '\n' || ch == '\r')
|
|
#endif
|
|
{
|
|
/* The newline is stored in the buffer along
|
|
* with the null terminator.
|
|
*/
|
|
|
|
s[nch++] = '\n';
|
|
s[nch] = '\0';
|
|
|
|
#ifdef CONFIG_FGETS_ECHO
|
|
if (console)
|
|
{
|
|
/* Echo the newline to the console */
|
|
|
|
_lib_consoleputc('\n');
|
|
}
|
|
#endif
|
|
return s;
|
|
}
|
|
|
|
/* Check for end-of-file */
|
|
|
|
else if (ch == EOF)
|
|
{
|
|
/* Terminate the line */
|
|
|
|
s[nch] = '\0';
|
|
return s;
|
|
}
|
|
|
|
/* Otherwise, check if the character is printable and,
|
|
* if so, put the character in the line buffer
|
|
*/
|
|
|
|
else if (isprint(ch))
|
|
{
|
|
s[nch++] = ch;
|
|
|
|
#ifdef CONFIG_FGETS_ECHO
|
|
if (console)
|
|
{
|
|
/* Echo the character to the console */
|
|
|
|
_lib_consoleputc(ch);
|
|
}
|
|
#endif
|
|
/* 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 >= n)
|
|
{
|
|
s[nch] = '\0';
|
|
return s;
|
|
}
|
|
}
|
|
}
|
|
|
|
}
|
|
|