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Diffstat (limited to 'apps/system/readline/readline_common.c')
| -rw-r--r-- | apps/system/readline/readline_common.c | 288 |
1 files changed, 288 insertions, 0 deletions
diff --git a/apps/system/readline/readline_common.c b/apps/system/readline/readline_common.c new file mode 100644 index 000000000..7f3806eac --- /dev/null +++ b/apps/system/readline/readline_common.c @@ -0,0 +1,288 @@ +/**************************************************************************** + * apps/system/readline/readline_common.c + * + * Copyright (C) 2007-2008, 2011-2013 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 <string.h> +#include <ctype.h> +#include <errno.h> +#include <assert.h> +#include <debug.h> + +#include <nuttx/ascii.h> +#include <nuttx/vt100.h> + +#include <apps/readline.h> +#include "readline.h" + +/**************************************************************************** + * Pre-processor Definitions + ****************************************************************************/ + +/**************************************************************************** + * 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[] = VT100_CLEAREOL; + +/**************************************************************************** + * Private Functions + ****************************************************************************/ + +/**************************************************************************** + * Public Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: readline_common + * + * readline() reads in at most one less than 'buflen' characters from + * 'instream' and stores them into the buffer pointed to by 'buf'. + * Characters are echoed on 'outstream'. 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. + * + * This version of realine assumes that we are reading and writing to + * a VT100 console. This will not work well if 'instream' or 'outstream' + * corresponds to a raw byte steam. + * + * This function is inspired by the GNU readline but is an entirely + * different creature. + * + * Input Parameters: + * buf - The user allocated buffer to be filled. + * buflen - the size of the buffer. + * instream - The stream to read characters from + * outstream - The stream to each characters to. + * + * Returned values: + * On success, the (positive) number of bytes transferred is returned. + * EOF is returned to indicate either an end of file condition or a + * failure. + * + **************************************************************************/ + +ssize_t readline_common(FAR struct rl_common_s *vtbl, FAR char *buf, int buflen) +{ + int escape; + int nch; + + /* Sanity checks */ + + DEBUGASSERT(buf && buflen > 0); + + if (buflen < 2) + { + *buf = '\0'; + return 0; + } + + /* <esc>[K is the VT100 command that erases to the end of the line. */ + +#ifdef CONFIG_READLINE_ECHO + RL_WRITE(vtbl, g_erasetoeol, sizeof(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. + */ + + escape = 0; + nch = 0; + + for(;;) + { + /* Get the next character. readline_rawgetc() returns EOF on any + * errors or at the end of file. + */ + + int ch = RL_GETC(vtbl); + + /* Check for end-of-file or read error */ + + if (ch == EOF) + { + /* Did we already received some data? */ + + if (nch > 0) + { + /* Yes.. Terminate the line (which might be zero length) + * and return the data that was received. The end-of-file + * or error condition will be reported next time. + */ + + buf[nch] = '\0'; + return nch; + } + + return EOF; + } + + /* Are we processing a VT100 escape sequence */ + + else if (escape) + { + /* Yes, is it an <esc>[, 3 byte sequence */ + + if (ch != ASCII_LBRACKET || 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 + * + * There are several notions of backspace, for an elaborate summary see + * http://www.ibb.net/~anne/keyboard.html. There is no clean solution. + * Here both DEL and backspace are treated like backspace here. The + * Unix/Linux screen terminal by default outputs DEL (0x7f) when the + * backspace key is pressed. + */ + + else if (ch == ASCII_BS || ch == ASCII_DEL) + { + /* Eliminate that last character in the buffer. */ + + if (nch > 0) + { + nch--; + +#ifdef CONFIG_READLINE_ECHO + /* Echo the backspace character on the console. Always output + * the backspace character because the VT100 terminal doesn't + * understand DEL properly. + */ + + RL_PUTC(vtbl, ASCII_BS); + RL_WRITE(vtbl, g_erasetoeol, sizeof(g_erasetoeol)); +#endif + } + } + + /* Check for the beginning of a VT100 escape sequence */ + + else if (ch == ASCII_ESC) + { + /* 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. + */ + + buf[nch++] = '\n'; + buf[nch] = '\0'; + +#ifdef CONFIG_READLINE_ECHO + /* Echo the newline to the console */ + + RL_PUTC(vtbl, '\n'); +#endif + return nch; + } + + /* Otherwise, check if the character is printable and, if so, put the + * character in the line buffer + */ + + else if (isprint(ch)) + { + buf[nch++] = ch; + +#ifdef CONFIG_READLINE_ECHO + /* Echo the character to the console */ + + RL_PUTC(vtbl, 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 >= buflen) + { + buf[nch] = '\0'; + return nch; + } + } + } +} + |