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84e0ca1310
nuttx-apps/system/readline/readline_common.c
Alin Jerpelea 84e0ca1310 system: update licenses to Apache 
Gregory Nutt is has submitted the SGA

Ken Pettit has submitted the ICLA

David S. Alessio has submitted the ICLA

as a result we can migrate the licenses to Apache.

Signed-off-by: Alin Jerpelea <alin.jerpelea@sony.com>
2021-06-11 02:42:05 -05:00

752 lines
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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. */
static const char g_erasetoeol[] = VT100_CLEAREOL;
#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')
{
strncpy(tmp_name, name, sizeof(tmp_name) - 1);
}
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
#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')
{
strncpy(tmp_name, name, sizeof(tmp_name) - 1);
}
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 < 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]);
}
}
}
#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.
*/
#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 defined(CONFIG_EOL_IS_EITHER_CRLF)
else if (ch == '\n' || ch == '\r')
#endif
{
#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) != 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';
#ifdef CONFIG_READLINE_ECHO
/* Echo the newline to the console */
RL_PUTC(vtbl, '\n');
#endif
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;
#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;
}
}
#ifdef CONFIG_READLINE_TABCOMPLETION
else if (ch == '\t') /* TAB character */
{
tab_completion(vtbl, buf, buflen, &nch);
}
#endif
}
}
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