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platform_system_core/liblinenoise/linenoise.c
Jack Palevich 192a288315 Improve linenoise.c compatability. 
+ Don't flush characters when switching into and out of raw mode. This
avoids eating characters that follow '\n'. (Such characters can occur
when pasting multiple line input, or when scripts are driving input.)

+ Try to be slightly cleverer about calculating the length of the prompt,
so that prompts with embedded '\n' characters are handled OK. This is
an area that really needs to be replaced with a query of the cursor
position from the terminal.

+ As a hack, just assume the screen is very wide if we don't know how
wide it is. This allows dexpropt to work correctly. (It was getting
confused by the editing commands emitted when the end-of-line was reached.)

Change-Id: I988dd0f0bceb22b298e915be0dde085c9358ef66
2010-06-04 14:32:01 +08:00

449 lines
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/* linenoise.c -- guerrilla line editing library against the idea that a
* line editing lib needs to be 20,000 lines of C code.
*
* You can find the latest source code at:
*
* http://github.com/antirez/linenoise
*
* Does a number of crazy assumptions that happen to be true in 99.9999% of
* the 2010 UNIX computers around.
*
* Copyright (c) 2010, Salvatore Sanfilippo <antirez at gmail dot com>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* * 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.
* * Neither the name of Redis 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.
*
* References:
* - http://invisible-island.net/xterm/ctlseqs/ctlseqs.html
* - http://www.3waylabs.com/nw/WWW/products/wizcon/vt220.html
*
* Todo list:
* - Switch to gets() if $TERM is something we can't support.
* - Filter bogus Ctrl+<char> combinations.
* - Win32 support
*
* Bloat:
* - Completion?
* - History search like Ctrl+r in readline?
*
* List of escape sequences used by this program, we do everything just
* with three sequences. In order to be so cheap we may have some
* flickering effect with some slow terminal, but the lesser sequences
* the more compatible.
*
* CHA (Cursor Horizontal Absolute)
* Sequence: ESC [ n G
* Effect: moves cursor to column n
*
* EL (Erase Line)
* Sequence: ESC [ n K
* Effect: if n is 0 or missing, clear from cursor to end of line
* Effect: if n is 1, clear from beginning of line to cursor
* Effect: if n is 2, clear entire line
*
* CUF (CUrsor Forward)
* Sequence: ESC [ n C
* Effect: moves cursor forward of n chars
*
*/
#include <termios.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/ioctl.h>
#include <unistd.h>
#define LINENOISE_MAX_LINE 4096
static char *unsupported_term[] = {"dumb","cons25",NULL};
static struct termios orig_termios; /* in order to restore at exit */
static int rawmode = 0; /* for atexit() function to check if restore is needed*/
static int atexit_registered = 0; /* register atexit just 1 time */
static int history_max_len = 100;
static int history_len = 0;
char **history = NULL;
static void linenoiseAtExit(void);
int linenoiseHistoryAdd(const char *line);
static int isUnsupportedTerm(void) {
char *term = getenv("TERM");
int j;
if (term == NULL) return 0;
for (j = 0; unsupported_term[j]; j++)
if (!strcasecmp(term,unsupported_term[j])) return 1;
return 0;
}
static void freeHistory(void) {
if (history) {
int j;
for (j = 0; j < history_len; j++)
free(history[j]);
free(history);
}
}
static int enableRawMode(int fd) {
struct termios raw;
if (!isatty(STDIN_FILENO)) goto fatal;
if (!atexit_registered) {
atexit(linenoiseAtExit);
atexit_registered = 1;
}
if (tcgetattr(fd,&orig_termios) == -1) goto fatal;
raw = orig_termios; /* modify the original mode */
/* input modes: no break, no CR to NL, no parity check, no strip char,
* no start/stop output control. */
raw.c_iflag &= ~(BRKINT | ICRNL | INPCK | ISTRIP | IXON);
/* output modes - disable post processing */
raw.c_oflag &= ~(OPOST);
/* control modes - set 8 bit chars */
raw.c_cflag |= (CS8);
/* local modes - choing off, canonical off, no extended functions,
* no signal chars (^Z,^C) */
raw.c_lflag &= ~(ECHO | ICANON | IEXTEN | ISIG);
/* control chars - set return condition: min number of bytes and timer.
* We want read to return every single byte, without timeout. */
raw.c_cc[VMIN] = 1; raw.c_cc[VTIME] = 0; /* 1 byte, no timer */
/* put terminal in raw mode */
if (tcsetattr(fd,TCSADRAIN,&raw) < 0) goto fatal;
rawmode = 1;
return 0;
fatal:
errno = ENOTTY;
return -1;
}
static void disableRawMode(int fd) {
/* Don't even check the return value as it's too late. */
if (rawmode && tcsetattr(fd,TCSADRAIN,&orig_termios) != -1)
rawmode = 0;
}
/* At exit we'll try to fix the terminal to the initial conditions. */
static void linenoiseAtExit(void) {
disableRawMode(STDIN_FILENO);
freeHistory();
}
static int getColumns(void) {
struct winsize ws;
if (ioctl(1, TIOCGWINSZ, &ws) == -1) return 4096;
if (ws.ws_col == 0) {
return 4096;
}
return ws.ws_col;
}
static int effectiveLen(const char* prompt) {
int col = 0;
char c;
// TODO: Handle escape sequences.
while ( (c = *prompt++) != 0 ) {
if (c == '\n') {
col = 0;
} else {
col++;
}
}
return col;
}
static void refreshLine(int fd, const char *prompt, char *buf, size_t len, size_t pos, size_t cols) {
char seq[64];
size_t plen = effectiveLen(prompt);
while((plen+pos) >= cols) {
buf++;
len--;
pos--;
}
while (plen+len > cols) {
len--;
}
/* Cursor to left edge */
snprintf(seq,64,"\x1b[0G");
if (write(fd,seq,strlen(seq)) == -1) return;
/* Write the prompt and the current buffer content */
if (write(fd,prompt,strlen(prompt)) == -1) return;
if (write(fd,buf,len) == -1) return;
/* Erase to right */
snprintf(seq,64,"\x1b[0K");
if (write(fd,seq,strlen(seq)) == -1) return;
/* Move cursor to original position. */
snprintf(seq,64,"\x1b[0G\x1b[%dC", (int)(pos+plen));
if (write(fd,seq,strlen(seq)) == -1) return;
}
static int linenoisePrompt(int fd, char *buf, size_t buflen, const char *prompt) {
size_t plen = strlen(prompt);
size_t pos = 0;
size_t len = 0;
size_t cols = getColumns();
int history_index = 0;
buf[0] = '\0';
buflen--; /* Make sure there is always space for the nulterm */
/* The latest history entry is always our current buffer, that
* initially is just an empty string. */
linenoiseHistoryAdd("");
if (write(fd,prompt,plen) == -1) return -1;
while(1) {
char c;
int nread;
char seq[2];
nread = read(fd,&c,1);
if (nread <= 0) return len;
switch(c) {
case 10: /* line feed. */
case 13: /* enter */
history_len--;
return len;
case 4: /* ctrl-d */
history_len--;
return (len == 0) ? -1 : (int)len;
case 3: /* ctrl-c */
errno = EAGAIN;
return -1;
case 127: /* backspace */
case 8: /* ctrl-h */
if (pos > 0 && len > 0) {
memmove(buf+pos-1,buf+pos,len-pos);
pos--;
len--;
buf[len] = '\0';
refreshLine(fd,prompt,buf,len,pos,cols);
}
break;
case 20: /* ctrl-t */
if (pos > 0 && pos < len) {
int aux = buf[pos-1];
buf[pos-1] = buf[pos];
buf[pos] = aux;
if (pos != len-1) pos++;
refreshLine(fd,prompt,buf,len,pos,cols);
}
break;
case 2: /* ctrl-b */
goto left_arrow;
case 6: /* ctrl-f */
goto right_arrow;
case 16: /* ctrl-p */
seq[1] = 65;
goto up_down_arrow;
case 14: /* ctrl-n */
seq[1] = 66;
goto up_down_arrow;
break;
case 27: /* escape sequence */
if (read(fd,seq,2) == -1) break;
if (seq[0] == 91 && seq[1] == 68) {
left_arrow:
/* left arrow */
if (pos > 0) {
pos--;
refreshLine(fd,prompt,buf,len,pos,cols);
}
} else if (seq[0] == 91 && seq[1] == 67) {
right_arrow:
/* right arrow */
if (pos != len) {
pos++;
refreshLine(fd,prompt,buf,len,pos,cols);
}
} else if (seq[0] == 91 && (seq[1] == 65 || seq[1] == 66)) {
up_down_arrow:
/* up and down arrow: history */
if (history_len > 1) {
/* Update the current history entry before to
* overwrite it with tne next one. */
free(history[history_len-1-history_index]);
history[history_len-1-history_index] = strdup(buf);
/* Show the new entry */
history_index += (seq[1] == 65) ? 1 : -1;
if (history_index < 0) {
history_index = 0;
break;
} else if (history_index >= history_len) {
history_index = history_len-1;
break;
}
strncpy(buf,history[history_len-1-history_index],buflen);
buf[buflen] = '\0';
len = pos = strlen(buf);
refreshLine(fd,prompt,buf,len,pos,cols);
}
}
break;
default:
if (len < buflen) {
if (len == pos) {
buf[pos] = c;
pos++;
len++;
buf[len] = '\0';
if (plen+len < cols) {
/* Avoid a full update of the line in the
* trivial case. */
if (write(fd,&c,1) == -1) return -1;
} else {
refreshLine(fd,prompt,buf,len,pos,cols);
}
} else {
memmove(buf+pos+1,buf+pos,len-pos);
buf[pos] = c;
len++;
pos++;
buf[len] = '\0';
refreshLine(fd,prompt,buf,len,pos,cols);
}
}
break;
case 21: /* Ctrl+u, delete the whole line. */
buf[0] = '\0';
pos = len = 0;
refreshLine(fd,prompt,buf,len,pos,cols);
break;
case 11: /* Ctrl+k, delete from current to end of line. */
buf[pos] = '\0';
len = pos;
refreshLine(fd,prompt,buf,len,pos,cols);
break;
case 1: /* Ctrl+a, go to the start of the line */
pos = 0;
refreshLine(fd,prompt,buf,len,pos,cols);
break;
case 5: /* ctrl+e, go to the end of the line */
pos = len;
refreshLine(fd,prompt,buf,len,pos,cols);
break;
}
}
return len;
}
static int linenoiseRaw(char *buf, size_t buflen, const char *prompt) {
int fd = STDIN_FILENO;
int count;
if (buflen == 0) {
errno = EINVAL;
return -1;
}
if (!isatty(STDIN_FILENO)) {
if (fgets(buf, buflen, stdin) == NULL) return -1;
count = strlen(buf);
if (count && buf[count-1] == '\n') {
count--;
buf[count] = '\0';
}
} else {
if (enableRawMode(fd) == -1) return -1;
count = linenoisePrompt(fd, buf, buflen, prompt);
disableRawMode(fd);
}
return count;
}
char *linenoise(const char *prompt) {
char buf[LINENOISE_MAX_LINE];
int count;
if (isUnsupportedTerm()) {
size_t len;
printf("%s",prompt);
fflush(stdout);
if (fgets(buf,LINENOISE_MAX_LINE,stdin) == NULL) return NULL;
len = strlen(buf);
while(len && (buf[len-1] == '\n' || buf[len-1] == '\r')) {
len--;
buf[len] = '\0';
}
return strdup(buf);
} else {
count = linenoiseRaw(buf,LINENOISE_MAX_LINE,prompt);
if (count == -1) return NULL;
return strdup(buf);
}
}
/* Using a circular buffer is smarter, but a bit more complex to handle. */
int linenoiseHistoryAdd(const char *line) {
char *linecopy;
if (history_max_len == 0) return 0;
if (history == 0) {
history = malloc(sizeof(char*)*history_max_len);
if (history == NULL) return 0;
memset(history,0,(sizeof(char*)*history_max_len));
}
linecopy = strdup(line);
if (!linecopy) return 0;
if (history_len == history_max_len) {
memmove(history,history+1,sizeof(char*)*(history_max_len-1));
history_len--;
}
history[history_len] = linecopy;
history_len++;
return 1;
}
int linenoiseHistorySetMaxLen(int len) {
char **new;
if (len < 1) return 0;
if (history) {
int tocopy = history_len;
new = malloc(sizeof(char*)*len);
if (new == NULL) return 0;
if (len < tocopy) tocopy = len;
memcpy(new,history+(history_max_len-tocopy), sizeof(char*)*tocopy);
free(history);
history = new;
}
history_max_len = len;
if (history_len > history_max_len)
history_len = history_max_len;
return 1;
}
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