1 /* linenoise.c -- guerrilla line editing library against the idea that a
2 * line editing lib needs to be 20,000 lines of C code.
4 * You can find the latest source code at:
6 * http://github.com/antirez/linenoise
8 * Does a number of crazy assumptions that happen to be true in 99.9999% of
9 * the 2010 UNIX computers around.
11 * Copyright (c) 2010, Salvatore Sanfilippo <antirez at gmail dot com>
12 * All rights reserved.
14 * Redistribution and use in source and binary forms, with or without
15 * modification, are permitted provided that the following conditions are met:
17 * * Redistributions of source code must retain the above copyright notice,
18 * this list of conditions and the following disclaimer.
19 * * Redistributions in binary form must reproduce the above copyright
20 * notice, this list of conditions and the following disclaimer in the
21 * documentation and/or other materials provided with the distribution.
22 * * Neither the name of Redis nor the names of its contributors may be used
23 * to endorse or promote products derived from this software without
24 * specific prior written permission.
26 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
27 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
30 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36 * POSSIBILITY OF SUCH DAMAGE.
39 * - http://invisible-island.net/xterm/ctlseqs/ctlseqs.html
40 * - http://www.3waylabs.com/nw/WWW/products/wizcon/vt220.html
43 * - Switch to gets() if $TERM is something we can't support.
44 * - Filter bogus Ctrl+<char> combinations.
49 * - History search like Ctrl+r in readline?
51 * List of escape sequences used by this program, we do everything just
52 * with three sequences. In order to be so cheap we may have some
53 * flickering effect with some slow terminal, but the lesser sequences
54 * the more compatible.
56 * CHA (Cursor Horizontal Absolute)
58 * Effect: moves cursor to column n
62 * Effect: if n is 0 or missing, clear from cursor to end of line
63 * Effect: if n is 1, clear from beginning of line to cursor
64 * Effect: if n is 2, clear entire line
66 * CUF (CUrsor Forward)
68 * Effect: moves cursor forward of n chars
79 #include <sys/types.h>
80 #include <sys/ioctl.h>
83 #define LINENOISE_MAX_LINE 4096
85 static struct termios orig_termios; /* in order to restore at exit */
86 static int rawmode = 0; /* for atexit() function to check if restore is needed*/
87 static int atexit_registered = 0; /* register atexit just 1 time */
88 static int history_max_len = 100;
89 static int history_len = 0;
90 char **history = NULL;
92 static void linenoiseAtExit(void);
93 int linenoiseHistoryAdd(char *line);
95 static void freeHistory(void) {
99 for (j = 0; j < history_len; j++)
105 static int enableRawMode(int fd) {
108 if (!isatty(STDIN_FILENO)) goto fatal;
109 if (!atexit_registered) {
110 atexit(linenoiseAtExit);
111 atexit_registered = 1;
113 if (tcgetattr(fd,&orig_termios) == -1) goto fatal;
115 raw = orig_termios; /* modify the original mode */
116 /* input modes: no break, no CR to NL, no parity check, no strip char,
117 * no start/stop output control. */
118 raw.c_iflag &= ~(BRKINT | ICRNL | INPCK | ISTRIP | IXON);
119 /* output modes - disable post processing */
120 raw.c_oflag &= ~(OPOST);
121 /* control modes - set 8 bit chars */
122 raw.c_cflag |= (CS8);
123 /* local modes - choing off, canonical off, no extended functions,
124 * no signal chars (^Z,^C) */
125 raw.c_lflag &= ~(ECHO | ICANON | IEXTEN | ISIG);
126 /* control chars - set return condition: min number of bytes and timer.
127 * We want read to return every single byte, without timeout. */
128 raw.c_cc[VMIN] = 1; raw.c_cc[VTIME] = 0; /* 1 byte, no timer */
130 /* put terminal in raw mode after flushing */
131 if (tcsetattr(fd,TCSAFLUSH,&raw) < 0) goto fatal;
140 static void disableRawMode(int fd) {
141 /* Don't even check the return value as it's too late. */
142 if (rawmode && tcsetattr(fd,TCSAFLUSH,&orig_termios) != -1)
146 /* At exit we'll try to fix the terminal to the initial conditions. */
147 static void linenoiseAtExit(void) {
148 disableRawMode(STDIN_FILENO);
152 static int getColumns(void) {
155 if (ioctl(1, TIOCGWINSZ, &ws) == -1) return 80;
159 static void refreshLine(int fd, const char *prompt, char *buf, size_t len, size_t pos, size_t cols) {
161 size_t plen = strlen(prompt);
163 while((plen+pos) >= cols) {
168 while (plen+len > cols) {
172 /* Cursor to left edge */
173 snprintf(seq,64,"\x1b[0G");
174 if (write(fd,seq,strlen(seq)) == -1) return;
175 /* Write the prompt and the current buffer content */
176 if (write(fd,prompt,strlen(prompt)) == -1) return;
177 if (write(fd,buf,len) == -1) return;
179 snprintf(seq,64,"\x1b[0K");
180 if (write(fd,seq,strlen(seq)) == -1) return;
181 /* Move cursor to original position. */
182 snprintf(seq,64,"\x1b[0G\x1b[%dC", (int)(pos+plen));
183 if (write(fd,seq,strlen(seq)) == -1) return;
186 static int linenoisePrompt(int fd, char *buf, size_t buflen, const char *prompt) {
187 size_t plen = strlen(prompt);
190 size_t cols = getColumns();
191 int history_index = 0;
194 buflen--; /* Make sure there is always space for the nulterm */
196 /* The latest history entry is always our current buffer, that
197 * initially is just an empty string. */
198 linenoiseHistoryAdd("");
200 if (write(fd,prompt,plen) == -1) return -1;
206 nread = read(fd,&c,1);
207 if (nread <= 0) return len;
214 return (len == 0) ? -1 : (int)len;
218 case 127: /* backspace */
220 if (pos > 0 && len > 0) {
221 memmove(buf+pos-1,buf+pos,len-pos);
225 refreshLine(fd,prompt,buf,len,pos,cols);
228 case 20: /* ctrl-t */
229 if (pos > 0 && pos < len) {
230 int aux = buf[pos-1];
231 buf[pos-1] = buf[pos];
233 if (pos != len-1) pos++;
234 refreshLine(fd,prompt,buf,len,pos,cols);
241 case 16: /* ctrl-p */
244 case 14: /* ctrl-n */
248 case 27: /* escape sequence */
249 if (read(fd,seq,2) == -1) break;
250 if (seq[0] == 91 && seq[1] == 68) {
255 refreshLine(fd,prompt,buf,len,pos,cols);
257 } else if (seq[0] == 91 && seq[1] == 67) {
262 refreshLine(fd,prompt,buf,len,pos,cols);
264 } else if (seq[0] == 91 && (seq[1] == 65 || seq[1] == 66)) {
266 /* up and down arrow: history */
267 if (history_len > 1) {
268 /* Update the current history entry before to
269 * overwrite it with tne next one. */
270 free(history[history_len-1-history_index]);
271 history[history_len-1-history_index] = strdup(buf);
272 /* Show the new entry */
273 history_index += (seq[1] == 65) ? 1 : -1;
274 if (history_index < 0) {
277 } else if (history_index >= history_len) {
278 history_index = history_len-1;
281 strncpy(buf,history[history_len-1-history_index],buflen);
283 len = pos = strlen(buf);
284 refreshLine(fd,prompt,buf,len,pos,cols);
295 if (plen+len < cols) {
296 /* Avoid a full update of the line in the
298 if (write(fd,&c,1) == -1) return -1;
300 refreshLine(fd,prompt,buf,len,pos,cols);
303 memmove(buf+pos+1,buf+pos,len-pos);
308 refreshLine(fd,prompt,buf,len,pos,cols);
312 case 21: /* Ctrl+u, delete the whole line. */
315 refreshLine(fd,prompt,buf,len,pos,cols);
317 case 11: /* Ctrl+k, delete from current to end of line. */
320 refreshLine(fd,prompt,buf,len,pos,cols);
322 case 1: /* Ctrl+a, go to the start of the line */
324 refreshLine(fd,prompt,buf,len,pos,cols);
326 case 5: /* ctrl+e, go to the end of the line */
328 refreshLine(fd,prompt,buf,len,pos,cols);
335 static int linenoiseRaw(char *buf, size_t buflen, const char *prompt) {
336 int fd = STDIN_FILENO;
343 if (enableRawMode(fd) == -1) return -1;
344 count = linenoisePrompt(fd, buf, buflen, prompt);
350 char *linenoise(const char *prompt) {
351 char buf[LINENOISE_MAX_LINE];
354 count = linenoiseRaw(buf,LINENOISE_MAX_LINE,prompt);
355 if (count == -1) return NULL;
359 /* Using a circular buffer is smarter, but a bit more complex to handle. */
360 int linenoiseHistoryAdd(char *line) {
361 if (history_max_len == 0) return 0;
363 history = malloc(sizeof(char*)*history_max_len);
364 if (history == NULL) return 0;
365 memset(history,0,(sizeof(char*)*history_max_len));
369 if (history_len == history_max_len) {
370 memmove(history,history+1,sizeof(char*)*(history_max_len-1));
373 history[history_len] = line;
378 int linenoiseHistorySetMaxLen(int len) {
381 if (len < 1) return 0;
383 int tocopy = history_len;
385 new = malloc(sizeof(char*)*len);
386 if (new == NULL) return 0;
387 if (len < tocopy) tocopy = len;
388 memcpy(new,history+(history_max_len-tocopy), sizeof(char*)*tocopy);
392 history_max_len = len;
393 if (history_len > history_max_len)
394 history_len = history_max_len;