deps/linenoise/linenoise.c

   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.
   3  *
   4  * You can find the latest source code at:
   5  *
   6  *   http://github.com/antirez/linenoise
   7  *
   8  * Does a number of crazy assumptions that happen to be true in 99.9999% of
   9  * the 2010 UNIX computers around.
  10  *
  11  * Copyright (c) 2010, Salvatore Sanfilippo <antirez at gmail dot com>
  12  * All rights reserved.
  13  *
  14  * Redistribution and use in source and binary forms, with or without
  15  * modification, are permitted provided that the following conditions are met:
  16  *
  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.
  25  *
  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.
  37  *
  38  * References:
  39  * - http://invisible-island.net/xterm/ctlseqs/ctlseqs.html
  40  * - http://www.3waylabs.com/nw/WWW/products/wizcon/vt220.html
  41  *
  42  * Todo list:
  43  * - Switch to gets() if $TERM is something we can't support.
  44  * - Filter bogus Ctrl+<char> combinations.
  45  * - Win32 support
  46  *
  47  * Bloat:
  48  * - Completion?
  49  * - History search like Ctrl+r in readline?
  50  *
  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.
  55  *
  56  * CHA (Cursor Horizontal Absolute)
  57  *    Sequence: ESC [ n G
  58  *    Effect: moves cursor to column n
  59  *
  60  * EL (Erase Line)
  61  *    Sequence: ESC [ n K
  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
  65  *
  66  * CUF (CUrsor Forward)
  67  *    Sequence: ESC [ n C
  68  *    Effect: moves cursor forward of n chars
  69  *
  70  */
  71
  72 #include <termios.h>
  73 #include <unistd.h>
  74 #include <stdlib.h>
  75 #include <stdio.h>
  76 #include <errno.h>
  77 #include <string.h>
  78 #include <stdlib.h>
  79 #include <sys/types.h>
  80 #include <sys/ioctl.h>
  81 #include <unistd.h>
  82 #include "linenoise.h"
  83
  84 #define LINENOISE_DEFAULT_HISTORY_MAX_LEN 100
  85 #define LINENOISE_MAX_LINE 4096
  86 static char *unsupported_term[] = {"dumb","cons25",NULL};
  87 static linenoiseCompletionCallback *completionCallback = NULL;
  88
  89 static struct termios orig_termios; /* in order to restore at exit */
  90 static int rawmode = 0; /* for atexit() function to check if restore is needed*/
  91 static int atexit_registered = 0; /* register atexit just 1 time */
  92 static int history_max_len = LINENOISE_DEFAULT_HISTORY_MAX_LEN;
  93 static int history_len = 0;
  94 char **history = NULL;
  95
  96 static void linenoiseAtExit(void);
  97 int linenoiseHistoryAdd(const char *line);
  98
  99 static int isUnsupportedTerm(void) {
 100     char *term = getenv("TERM");
 101     int j;
 102
 103     if (term == NULL) return 0;
 104     for (j = 0; unsupported_term[j]; j++)
 105         if (!strcasecmp(term,unsupported_term[j])) return 1;
 106     return 0;
 107 }
 108
 109 static void freeHistory(void) {
 110     if (history) {
 111         int j;
 112
 113         for (j = 0; j < history_len; j++)
 114             free(history[j]);
 115         free(history);
 116     }
 117 }
 118
 119 static int enableRawMode(int fd) {
 120     struct termios raw;
 121
 122     if (!isatty(STDIN_FILENO)) goto fatal;
 123     if (!atexit_registered) {
 124         atexit(linenoiseAtExit);
 125         atexit_registered = 1;
 126     }
 127     if (tcgetattr(fd,&orig_termios) == -1) goto fatal;
 128
 129     raw = orig_termios;  /* modify the original mode */
 130     /* input modes: no break, no CR to NL, no parity check, no strip char,
 131      * no start/stop output control. */
 132     raw.c_iflag &= ~(BRKINT | ICRNL | INPCK | ISTRIP | IXON);
 133     /* output modes - disable post processing */
 134     raw.c_oflag &= ~(OPOST);
 135     /* control modes - set 8 bit chars */
 136     raw.c_cflag |= (CS8);
 137     /* local modes - choing off, canonical off, no extended functions,
 138      * no signal chars (^Z,^C) */
 139     raw.c_lflag &= ~(ECHO | ICANON | IEXTEN | ISIG);
 140     /* control chars - set return condition: min number of bytes and timer.
 141      * We want read to return every single byte, without timeout. */
 142     raw.c_cc[VMIN] = 1; raw.c_cc[VTIME] = 0; /* 1 byte, no timer */
 143
 144     /* put terminal in raw mode after flushing */
 145     if (tcsetattr(fd,TCSAFLUSH,&raw) < 0) goto fatal;
 146     rawmode = 1;
 147     return 0;
 148
 149 fatal:
 150     errno = ENOTTY;
 151     return -1;
 152 }
 153
 154 static void disableRawMode(int fd) {
 155     /* Don't even check the return value as it's too late. */
 156     if (rawmode && tcsetattr(fd,TCSAFLUSH,&orig_termios) != -1)
 157         rawmode = 0;
 158 }
 159
 160 /* At exit we'll try to fix the terminal to the initial conditions. */
 161 static void linenoiseAtExit(void) {
 162     disableRawMode(STDIN_FILENO);
 163     freeHistory();
 164 }
 165
 166 static int getColumns(void) {
 167     struct winsize ws;
 168
 169     if (ioctl(1, TIOCGWINSZ, &ws) == -1) return 80;
 170     return ws.ws_col;
 171 }
 172
 173 static void refreshLine(int fd, const char *prompt, char *buf, size_t len, size_t pos, size_t cols) {
 174     char seq[64];
 175     size_t plen = strlen(prompt);
 176
 177     while((plen+pos) >= cols) {
 178         buf++;
 179         len--;
 180         pos--;
 181     }
 182     while (plen+len > cols) {
 183         len--;
 184     }
 185
 186     /* Cursor to left edge */
 187     snprintf(seq,64,"\x1b[0G");
 188     if (write(fd,seq,strlen(seq)) == -1) return;
 189     /* Write the prompt and the current buffer content */
 190     if (write(fd,prompt,strlen(prompt)) == -1) return;
 191     if (write(fd,buf,len) == -1) return;
 192     /* Erase to right */
 193     snprintf(seq,64,"\x1b[0K");
 194     if (write(fd,seq,strlen(seq)) == -1) return;
 195     /* Move cursor to original position. */
 196     snprintf(seq,64,"\x1b[0G\x1b[%dC", (int)(pos+plen));
 197     if (write(fd,seq,strlen(seq)) == -1) return;
 198 }
 199
 200 static void beep() {
 201     fprintf(stderr, "\x7");
 202     fflush(stderr);
 203 }
 204
 205 static void freeCompletions(linenoiseCompletions *lc) {
 206     size_t i;
 207     for (i = 0; i < lc->len; i++)
 208         free(lc->cvec[i]);
 209     if (lc->cvec != NULL)
 210         free(lc->cvec);
 211 }
 212
 213 static int completeLine(int fd, const char *prompt, char *buf, size_t buflen, size_t *len, size_t *pos, size_t cols) {
 214     linenoiseCompletions lc = { 0, NULL };
 215     int nread, nwritten;
 216     char c = 0;
 217
 218     completionCallback(buf,&lc);
 219     if (lc.len == 0) {
 220         beep();
 221     } else {
 222         size_t stop = 0, i = 0;
 223         size_t clen;
 224
 225         while(!stop) {
 226             /* Show completion or original buffer */
 227             if (i < lc.len) {
 228                 clen = strlen(lc.cvec[i]);
 229                 refreshLine(fd,prompt,lc.cvec[i],clen,clen,cols);
 230             } else {
 231                 refreshLine(fd,prompt,buf,*len,*pos,cols);
 232             }
 233
 234             nread = read(fd,&c,1);
 235             if (nread <= 0) {
 236                 freeCompletions(&lc);
 237                 return -1;
 238             }
 239
 240             switch(c) {
 241                 case 9: /* tab */
 242                     i = (i+1) % (lc.len+1);
 243                     if (i == lc.len) beep();
 244                     break;
 245                 case 27: /* escape */
 246                     /* Re-show original buffer */
 247                     if (i < lc.len) {
 248                         refreshLine(fd,prompt,buf,*len,*pos,cols);
 249                     }
 250                     stop = 1;
 251                     break;
 252                 default:
 253                     /* Update buffer and return */
 254                     if (i < lc.len) {
 255                         nwritten = snprintf(buf,buflen,"%s",lc.cvec[i]);
 256                         *len = *pos = nwritten;
 257                     }
 258                     stop = 1;
 259                     break;
 260             }
 261         }
 262     }
 263
 264     freeCompletions(&lc);
 265     return c; /* Return last read character */
 266 }
 267
 268 static int linenoisePrompt(int fd, char *buf, size_t buflen, const char *prompt) {
 269     size_t plen = strlen(prompt);
 270     size_t pos = 0;
 271     size_t len = 0;
 272     size_t cols = getColumns();
 273     int history_index = 0;
 274
 275     buf[0] = '\0';
 276     buflen--; /* Make sure there is always space for the nulterm */
 277
 278     /* The latest history entry is always our current buffer, that
 279      * initially is just an empty string. */
 280     linenoiseHistoryAdd("");
 281
 282     if (write(fd,prompt,plen) == -1) return -1;
 283     while(1) {
 284         char c;
 285         int nread;
 286         char seq[2], seq2[2];
 287
 288         nread = read(fd,&c,1);
 289         if (nread <= 0) return len;
 290
 291         /* Only autocomplete when the callback is set. It returns < 0 when
 292          * there was an error reading from fd. Otherwise it will return the
 293          * character that should be handled next. */
 294         if (c == 9 && completionCallback != NULL) {
 295             c = completeLine(fd,prompt,buf,buflen,&len,&pos,cols);
 296             /* Return on errors */
 297             if (c < 0) return len;
 298             /* Read next character when 0 */
 299             if (c == 0) continue;
 300         }
 301
 302         switch(c) {
 303         case 13:    /* enter */
 304         case 4:     /* ctrl-d */
 305             history_len--;
 306             free(history[history_len]);
 307             return (len == 0 && c == 4) ? -1 : (int)len;
 308         case 3:     /* ctrl-c */
 309             errno = EAGAIN;
 310             return -1;
 311         case 127:   /* backspace */
 312         case 8:     /* ctrl-h */
 313             if (pos > 0 && len > 0) {
 314                 memmove(buf+pos-1,buf+pos,len-pos);
 315                 pos--;
 316                 len--;
 317                 buf[len] = '\0';
 318                 refreshLine(fd,prompt,buf,len,pos,cols);
 319             }
 320             break;
 321         case 20:    /* ctrl-t */
 322             if (pos > 0 && pos < len) {
 323                 int aux = buf[pos-1];
 324                 buf[pos-1] = buf[pos];
 325                 buf[pos] = aux;
 326                 if (pos != len-1) pos++;
 327                 refreshLine(fd,prompt,buf,len,pos,cols);
 328             }
 329             break;
 330         case 2:     /* ctrl-b */
 331             goto left_arrow;
 332         case 6:     /* ctrl-f */
 333             goto right_arrow;
 334         case 16:    /* ctrl-p */
 335             seq[1] = 65;
 336             goto up_down_arrow;
 337         case 14:    /* ctrl-n */
 338             seq[1] = 66;
 339             goto up_down_arrow;
 340             break;
 341         case 27:    /* escape sequence */
 342             if (read(fd,seq,2) == -1) break;
 343             if (seq[0] == 91 && seq[1] == 68) {
 344 left_arrow:
 345                 /* left arrow */
 346                 if (pos > 0) {
 347                     pos--;
 348                     refreshLine(fd,prompt,buf,len,pos,cols);
 349                 }
 350             } else if (seq[0] == 91 && seq[1] == 67) {
 351 right_arrow:
 352                 /* right arrow */
 353                 if (pos != len) {
 354                     pos++;
 355                     refreshLine(fd,prompt,buf,len,pos,cols);
 356                 }
 357             } else if (seq[0] == 91 && (seq[1] == 65 || seq[1] == 66)) {
 358 up_down_arrow:
 359                 /* up and down arrow: history */
 360                 if (history_len > 1) {
 361                     /* Update the current history entry before to
 362                      * overwrite it with tne next one. */
 363                     free(history[history_len-1-history_index]);
 364                     history[history_len-1-history_index] = strdup(buf);
 365                     /* Show the new entry */
 366                     history_index += (seq[1] == 65) ? 1 : -1;
 367                     if (history_index < 0) {
 368                         history_index = 0;
 369                         break;
 370                     } else if (history_index >= history_len) {
 371                         history_index = history_len-1;
 372                         break;
 373                     }
 374                     strncpy(buf,history[history_len-1-history_index],buflen);
 375                     buf[buflen] = '\0';
 376                     len = pos = strlen(buf);
 377                     refreshLine(fd,prompt,buf,len,pos,cols);
 378                 }
 379             } else if (seq[0] == 91 && seq[1] > 48 && seq[1] < 55) {
 380                 /* extended escape */
 381                 if (read(fd,seq2,2) == -1) break;
 382                 if (seq[1] == 51 && seq2[0] == 126) {
 383                     /* delete */
 384                     if (len > 0 && pos < len) {
 385                         memmove(buf+pos,buf+pos+1,len-pos-1);
 386                         len--;
 387                         buf[len] = '\0';
 388                         refreshLine(fd,prompt,buf,len,pos,cols);
 389                     }
 390                 }
 391             }
 392             break;
 393         default:
 394             if (len < buflen) {
 395                 if (len == pos) {
 396                     buf[pos] = c;
 397                     pos++;
 398                     len++;
 399                     buf[len] = '\0';
 400                     if (plen+len < cols) {
 401                         /* Avoid a full update of the line in the
 402                          * trivial case. */
 403                         if (write(fd,&c,1) == -1) return -1;
 404                     } else {
 405                         refreshLine(fd,prompt,buf,len,pos,cols);
 406                     }
 407                 } else {
 408                     memmove(buf+pos+1,buf+pos,len-pos);
 409                     buf[pos] = c;
 410                     len++;
 411                     pos++;
 412                     buf[len] = '\0';
 413                     refreshLine(fd,prompt,buf,len,pos,cols);
 414                 }
 415             }
 416             break;
 417         case 21: /* Ctrl+u, delete the whole line. */
 418             buf[0] = '\0';
 419             pos = len = 0;
 420             refreshLine(fd,prompt,buf,len,pos,cols);
 421             break;
 422         case 11: /* Ctrl+k, delete from current to end of line. */
 423             buf[pos] = '\0';
 424             len = pos;
 425             refreshLine(fd,prompt,buf,len,pos,cols);
 426             break;
 427         case 1: /* Ctrl+a, go to the start of the line */
 428             pos = 0;
 429             refreshLine(fd,prompt,buf,len,pos,cols);
 430             break;
 431         case 5: /* ctrl+e, go to the end of the line */
 432             pos = len;
 433             refreshLine(fd,prompt,buf,len,pos,cols);
 434             break;
 435         }
 436     }
 437     return len;
 438 }
 439
 440 static int linenoiseRaw(char *buf, size_t buflen, const char *prompt) {
 441     int fd = STDIN_FILENO;
 442     int count;
 443
 444     if (buflen == 0) {
 445         errno = EINVAL;
 446         return -1;
 447     }
 448     if (!isatty(STDIN_FILENO)) {
 449         if (fgets(buf, buflen, stdin) == NULL) return -1;
 450         count = strlen(buf);
 451         if (count && buf[count-1] == '\n') {
 452             count--;
 453             buf[count] = '\0';
 454         }
 455     } else {
 456         if (enableRawMode(fd) == -1) return -1;
 457         count = linenoisePrompt(fd, buf, buflen, prompt);
 458         disableRawMode(fd);
 459         printf("\n");
 460     }
 461     return count;
 462 }
 463
 464 char *linenoise(const char *prompt) {
 465     char buf[LINENOISE_MAX_LINE];
 466     int count;
 467
 468     if (isUnsupportedTerm()) {
 469         size_t len;
 470
 471         printf("%s",prompt);
 472         fflush(stdout);
 473         if (fgets(buf,LINENOISE_MAX_LINE,stdin) == NULL) return NULL;
 474         len = strlen(buf);
 475         while(len && (buf[len-1] == '\n' || buf[len-1] == '\r')) {
 476             len--;
 477             buf[len] = '\0';
 478         }
 479         return strdup(buf);
 480     } else {
 481         count = linenoiseRaw(buf,LINENOISE_MAX_LINE,prompt);
 482         if (count == -1) return NULL;
 483         return strdup(buf);
 484     }
 485 }
 486
 487 /* Register a callback function to be called for tab-completion. */
 488 void linenoiseSetCompletionCallback(linenoiseCompletionCallback *fn) {
 489     completionCallback = fn;
 490 }
 491
 492 void linenoiseAddCompletion(linenoiseCompletions *lc, char *str) {
 493     size_t len = strlen(str);
 494     char *copy = malloc(len+1);
 495     memcpy(copy,str,len+1);
 496     lc->cvec = realloc(lc->cvec,sizeof(char*)*(lc->len+1));
 497     lc->cvec[lc->len++] = copy;
 498 }
 499
 500 /* Using a circular buffer is smarter, but a bit more complex to handle. */
 501 int linenoiseHistoryAdd(const char *line) {
 502     char *linecopy;
 503
 504     if (history_max_len == 0) return 0;
 505     if (history == NULL) {
 506         history = malloc(sizeof(char*)*history_max_len);
 507         if (history == NULL) return 0;
 508         memset(history,0,(sizeof(char*)*history_max_len));
 509     }
 510     linecopy = strdup(line);
 511     if (!linecopy) return 0;
 512     if (history_len == history_max_len) {
 513         free(history[0]);
 514         memmove(history,history+1,sizeof(char*)*(history_max_len-1));
 515         history_len--;
 516     }
 517     history[history_len] = linecopy;
 518     history_len++;
 519     return 1;
 520 }
 521
 522 int linenoiseHistorySetMaxLen(int len) {
 523     char **new;
 524
 525     if (len < 1) return 0;
 526     if (history) {
 527         int tocopy = history_len;
 528
 529         new = malloc(sizeof(char*)*len);
 530         if (new == NULL) return 0;
 531         if (len < tocopy) tocopy = len;
 532         memcpy(new,history+(history_max_len-tocopy), sizeof(char*)*tocopy);
 533         free(history);
 534         history = new;
 535     }
 536     history_max_len = len;
 537     if (history_len > history_max_len)
 538         history_len = history_max_len;
 539     return 1;
 540 }
 541
 542 /* Save the history in the specified file. On success 0 is returned
 543  * otherwise -1 is returned. */
 544 int linenoiseHistorySave(char *filename) {
 545     FILE *fp = fopen(filename,"w");
 546     int j;
 547
 548     if (fp == NULL) return -1;
 549     for (j = 0; j < history_len; j++)
 550         fprintf(fp,"%s\n",history[j]);
 551     fclose(fp);
 552     return 0;
 553 }
 554
 555 /* Load the history from the specified file. If the file does not exist
 556  * zero is returned and no operation is performed.
 557  *
 558  * If the file exists and the operation succeeded 0 is returned, otherwise
 559  * on error -1 is returned. */
 560 int linenoiseHistoryLoad(char *filename) {
 561     FILE *fp = fopen(filename,"r");
 562     char buf[LINENOISE_MAX_LINE];
 563
 564     if (fp == NULL) return -1;
 565
 566     while (fgets(buf,LINENOISE_MAX_LINE,fp) != NULL) {
 567         char *p;
 568
 569         p = strchr(buf,'\r');
 570         if (!p) p = strchr(buf,'\n');
 571         if (p) *p = '\0';
 572         linenoiseHistoryAdd(buf);
 573     }
 574     fclose(fp);
 575     return 0;
 576 }