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nuttx-apps/system/readline/readline_common.c
Huang Qi 8160dd0d56 readline: Don't echo input except VT100 command 
Let's echo character by serial driver,
this will imporve the experience of telnetd,
which will display input command and newline twice.
And also enhance the compatiblity with some third party
linux readline based application (like WAMR repl).

Signed-off-by: Huang Qi <huangqi3@xiaomi.com>
2023-03-02 13:46:18 +08:00

740 lines
21 KiB
C
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/****************************************************************************
* apps/system/readline/readline_common.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* 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 <nuttx/lib/builtin.h>
#include "system/readline.h"
#include "readline.h"
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#ifdef CONFIG_READLINE_CMD_HISTORY
# define RL_CMDHIST_LEN CONFIG_READLINE_CMD_HISTORY_LEN
# define RL_CMDHIST_LINELEN CONFIG_READLINE_CMD_HISTORY_LINELEN
#endif
/****************************************************************************
* Private Types
****************************************************************************/
#ifdef CONFIG_READLINE_CMD_HISTORY
struct cmdhist_s
{
char buf[RL_CMDHIST_LEN][RL_CMDHIST_LINELEN]; /* Circular buffer */
int head; /* Head of the circular buffer */
int offset; /* Offset from head */
int len; /* Size of the circular buffer */
};
#endif /* CONFIG_READLINE_CMD_HISTORY */
/****************************************************************************
* Private Data
****************************************************************************/
/* <esc>[K is the VT100 command erases to the end of the line. */
#ifdef CONFIG_READLINE_ECHO
static const char g_erasetoeol[] = VT100_CLEAREOL;
#endif
#ifdef CONFIG_READLINE_TABCOMPLETION
/* Prompt string to present at the beginning of the line */
static FAR const char *g_readline_prompt = NULL;
#ifdef CONFIG_READLINE_HAVE_EXTMATCH
static FAR const struct extmatch_vtable_s *g_extmatch_vtbl = NULL;
#endif
#endif /* CONFIG_READLINE_TABCOMPLETION */
#ifdef CONFIG_READLINE_CMD_HISTORY
static struct cmdhist_s g_cmdhist;
#endif /* CONFIG_READLINE_CMD_HISTORY */
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: count_builtin_matches
*
* Description:
* Count the number of builtin commands
*
* Input Parameters:
* matches - Array to save builtin command index.
* len - The length of the matching name to try
*
* Returned Value:
* The number of matching names
*
****************************************************************************/
#if defined(CONFIG_READLINE_TABCOMPLETION) && defined(CONFIG_BUILTIN)
static int count_builtin_matches(FAR char *buf, FAR int *matches,
int namelen)
{
#if CONFIG_READLINE_MAX_BUILTINS > 0
FAR const char *name;
int nr_matches = 0;
int i;
for (i = 0; (name = builtin_getname(i)) != NULL; i++)
{
if (strncmp(buf, name, namelen) == 0)
{
matches[nr_matches] = i;
nr_matches++;
if (nr_matches >= CONFIG_READLINE_MAX_BUILTINS)
{
break;
}
}
}
return nr_matches;
#else
return 0;
#endif
}
#endif
/****************************************************************************
* Name: tab_completion
*
* Description:
* Unix like tab completion, only for builtin apps
*
* Input Parameters:
* vtbl - vtbl used to access implementation specific interface
* buf - The user allocated buffer to be filled.
* buflen - the size of the buffer.
* nch - the number of characters.
*
* Returned Value:
* None.
*
****************************************************************************/
#ifdef CONFIG_READLINE_TABCOMPLETION
static void tab_completion(FAR struct rl_common_s *vtbl, char *buf,
int buflen, int *nch)
{
FAR const char *name = NULL;
char tmp_name[CONFIG_TASK_NAME_SIZE + 1];
#ifdef CONFIG_BUILTIN
int nr_builtin_matches = 0;
int builtin_matches[CONFIG_READLINE_MAX_BUILTINS];
#endif
#ifdef CONFIG_READLINE_HAVE_EXTMATCH
int nr_ext_matches = 0;
int ext_matches[CONFIG_READLINE_MAX_EXTCMDS];
#endif
int nr_matches;
int len = *nch;
int name_len;
int i;
int j;
if (len >= 1)
{
#ifdef CONFIG_BUILTIN
/* Count the matching builtin commands */
nr_builtin_matches = count_builtin_matches(buf, builtin_matches, len);
nr_matches = nr_builtin_matches;
#else
nr_matches = 0;
#endif
#ifdef CONFIG_READLINE_HAVE_EXTMATCH
/* Is there registered external handling logic? */
nr_ext_matches = 0;
if (g_extmatch_vtbl != NULL)
{
/* Count the number of external commands */
nr_ext_matches =
g_extmatch_vtbl->count_matches(buf, ext_matches, len);
nr_matches += nr_ext_matches;
}
#endif
/* Is there only one matching name? */
if (nr_matches == 1)
{
/* Yes... that that is the one we want. Was it a match with a
* builtin command? Or with an external command.
*/
#ifdef CONFIG_BUILTIN
#ifdef CONFIG_READLINE_HAVE_EXTMATCH
if (nr_builtin_matches == 1)
#endif
{
/* It is a match with a builtin command */
name = builtin_getname(builtin_matches[0]);
}
#endif
#ifdef CONFIG_READLINE_HAVE_EXTMATCH
#ifdef CONFIG_BUILTIN
else
#endif
{
/* It is a match with an external command */
name = g_extmatch_vtbl->getname(ext_matches[0]);
}
#endif
/* Copy the name to the command buffer and to the display. */
name_len = strlen(name);
for (j = len; j < name_len; j++)
{
buf[j] = name[j];
RL_PUTC(vtbl, name[j]);
}
/* Don't remove extra characters after the completed word,
* if any.
*/
if (len < name_len)
{
*nch = name_len;
}
}
/* Are there multiple matching names? */
else if (nr_matches > 1)
{
RL_PUTC(vtbl, '\n');
/* See how many characters we can auto complete for the user
* For example, if we have the following commands:
* - prog1
* - prog2
* - prog3
* then it should automatically complete up to prog.
* We do this in one pass using a temp.
*/
memset(tmp_name, 0, sizeof(tmp_name));
#ifdef CONFIG_READLINE_HAVE_EXTMATCH
/* Show the possible external completions */
for (i = 0; i < nr_ext_matches; i++)
{
name = g_extmatch_vtbl->getname(ext_matches[i]);
/* Initialize temp */
if (tmp_name[0] == '\0')
{
strlcpy(tmp_name, name, sizeof(tmp_name));
}
RL_PUTC(vtbl, ' ');
RL_PUTC(vtbl, ' ');
for (j = 0; j < (int)strlen(name); j++)
{
/* Removing characters that aren't common to all the
* matches.
*/
if (j < (int)sizeof(tmp_name) && name[j] != tmp_name[j])
{
tmp_name[j] = '\0';
}
RL_PUTC(vtbl, name[j]);
}
RL_PUTC(vtbl, '\n');
}
#endif
#ifdef CONFIG_BUILTIN
/* Show the possible builtin completions */
for (i = 0; i < nr_builtin_matches; i++)
{
name = builtin_getname(builtin_matches[i]);
/* Initialize temp */
if (tmp_name[0] == '\0')
{
strlcpy(tmp_name, name, sizeof(tmp_name));
}
RL_PUTC(vtbl, ' ');
RL_PUTC(vtbl, ' ');
for (j = 0; j < strlen(name); j++)
{
/* Removing characters that aren't common to all the
* matches.
*/
if (j < sizeof(tmp_name) && name[j] != tmp_name[j])
{
tmp_name[j] = '\0';
}
RL_PUTC(vtbl, name[j]);
}
RL_PUTC(vtbl, '\n');
}
#endif
strncpy(buf, tmp_name, buflen - 1);
name_len = strlen(tmp_name);
/* Output the original prompt */
if (g_readline_prompt != NULL)
{
for (i = 0; i < (int)strlen(g_readline_prompt); i++)
{
RL_PUTC(vtbl, g_readline_prompt[i]);
}
}
for (i = 0; i < name_len; i++)
{
RL_PUTC(vtbl, buf[i]);
}
/* Don't remove extra characters after the completed word,
* if any
*/
if (len < name_len)
{
*nch = name_len;
}
}
}
}
#endif
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: readline_prompt
*
* If a prompt string is used by the application, then the application
* must provide the prompt string to readline() by calling this function.
* This is needed only for tab completion in cases where is it necessary
* to reprint the prompt string.
*
* Input Parameters:
* prompt - The prompt string. This function may then be
* called with that value in order to restore the previous vtable.
*
* Returned values:
* Returns the previous value of the prompt string. This function may
* then be called with that value in order to restore the previous prompt.
*
* Assumptions:
* The prompt string is statically allocated a global. readline() will
* simply remember the pointer to the string. The string must stay
* allocated and available. Only one prompt string is supported. If
* there are multiple clients of readline(), they must all share the same
* prompt string (with exceptions in the case of the kernel build).
*
****************************************************************************/
#ifdef CONFIG_READLINE_TABCOMPLETION
FAR const char *readline_prompt(FAR const char *prompt)
{
FAR const char *ret = g_readline_prompt;
g_readline_prompt = prompt;
return ret;
}
#endif
/****************************************************************************
* Name: readline_extmatch
*
* If the applications supports a command set, then it may call this
* function in order to provide support for tab complete on these
* "external" commands
*
* Input Parameters:
* vtbl - Callbacks to access the external names.
*
* Returned values:
* Returns the previous vtable pointer. This function may then be
* called with that value in order to restore the previous vtable.
*
* Assumptions:
* The vtbl string is statically allocated a global. readline() will
* simply remember the pointer to the structure. The structure must stay
* allocated and available. Only one instance of such a structure is
* supported. If there are multiple clients of readline(), they must all
* share the same tab-completion logic (with exceptions in the case of
* the kernel build).
*
****************************************************************************/
#if defined(CONFIG_READLINE_TABCOMPLETION) && defined(CONFIG_READLINE_HAVE_EXTMATCH)
FAR const struct extmatch_vtable_s *
readline_extmatch(FAR const struct extmatch_vtable_s *vtbl)
{
#if (CONFIG_READLINE_MAX_EXTCMDS > 0)
FAR const struct extmatch_vtable_s *ret = g_extmatch_vtbl;
g_extmatch_vtbl = vtbl;
return ret;
#else
return NULL;
#endif
}
#endif
/****************************************************************************
* Name: readline_common
*
* Description:
* 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:
* vtbl - vtbl used to access implementation specific interface
* buf - The user allocated buffer to be filled.
* buflen - the size of the buffer.
*
* Returned Value:
* 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;
#ifdef CONFIG_READLINE_CMD_HISTORY
int i;
#endif
/* 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 */
#ifdef CONFIG_READLINE_CMD_HISTORY
/* Intercept up and down arrow keys */
if (g_cmdhist.len > 0)
{
if (ch == 'A') /* up arrow */
{
/* Go to the past command in history */
g_cmdhist.offset--;
if (-g_cmdhist.offset >= g_cmdhist.len)
{
g_cmdhist.offset = -(g_cmdhist.len - 1);
}
}
else if (ch == 'B') /* down arrow */
{
/* Go to the recent command in history */
g_cmdhist.offset++;
if (g_cmdhist.offset > 1)
{
g_cmdhist.offset = 1;
}
}
/* Clear out current command from the prompt */
while (nch > 0)
{
nch--;
#ifdef CONFIG_READLINE_ECHO
RL_PUTC(vtbl, ASCII_BS);
RL_WRITE(vtbl, g_erasetoeol, sizeof(g_erasetoeol));
#endif
}
if (g_cmdhist.offset != 1)
{
int idx = g_cmdhist.head + g_cmdhist.offset;
/* Circular buffer wrap around */
if (idx < 0)
{
idx = idx + RL_CMDHIST_LEN;
}
else if (idx >= RL_CMDHIST_LEN)
{
idx = idx - RL_CMDHIST_LEN;
}
for (i = 0; g_cmdhist.buf[idx][i] != '\0'; i++)
{
buf[nch++] = g_cmdhist.buf[idx][i];
RL_PUTC(vtbl, g_cmdhist.buf[idx][i]);
}
buf[nch] = '\0';
}
}
#endif /* CONFIG_READLINE_CMD_HISTORY */
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.
*/
else if (ch == '\n')
{
#ifdef CONFIG_READLINE_CMD_HISTORY
/* Save history of command, only if there was something
* typed besides return character.
*/
if (nch >= 1)
{
/* If this command is the one at the top of the circular
* buffer, don't save it again.
*/
if (strncmp(buf, g_cmdhist.buf[g_cmdhist.head], nch + 1) != 0)
{
g_cmdhist.head = (g_cmdhist.head + 1) % RL_CMDHIST_LEN;
for (i = 0; (i < nch) && i < (RL_CMDHIST_LINELEN - 1); i++)
{
g_cmdhist.buf[g_cmdhist.head][i] = buf[i];
}
g_cmdhist.buf[g_cmdhist.head][i] = '\0';
if (g_cmdhist.len < RL_CMDHIST_LEN)
{
g_cmdhist.len++;
}
}
g_cmdhist.offset = 1;
}
#endif /* CONFIG_READLINE_CMD_HISTORY */
/* The newline is stored in the buffer along with the null
* terminator.
*/
buf[nch++] = '\n';
buf[nch] = '\0';
return nch;
}
/* Otherwise, put the character in the line buffer if the
* character is not a control byte
*/
else if (!iscntrl(ch & 0xff))
{
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 nch;
}
}
#ifdef CONFIG_READLINE_TABCOMPLETION
else if (ch == '\t') /* TAB character */
{
tab_completion(vtbl, buf, buflen, &nch);
}
#endif
}
}
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