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  * Copyright (c) 2010, Pieter Noordhuis <pcnoordhuis at gmail dot com>
  13  *
  14  * All rights reserved.
  15  *
  16  * Redistribution and use in source and binary forms, with or without
  17  * modification, are permitted provided that the following conditions are met:
  18  *
  19  *   * Redistributions of source code must retain the above copyright notice,
  20  *     this list of conditions and the following disclaimer.
  21  *   * Redistributions in binary form must reproduce the above copyright
  22  *     notice, this list of conditions and the following disclaimer in the
  23  *     documentation and/or other materials provided with the distribution.
  24  *   * Neither the name of Redis nor the names of its contributors may be used
  25  *     to endorse or promote products derived from this software without
  26  *     specific prior written permission.
  27  *
  28  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  29  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  30  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  31  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  32  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  33  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  34  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  35  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  36  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  37  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  38  * POSSIBILITY OF SUCH DAMAGE.
  39  *
  40  * References:
  41  * - http://invisible-island.net/xterm/ctlseqs/ctlseqs.html
  42  * - http://www.3waylabs.com/nw/WWW/products/wizcon/vt220.html
  43  *
  44  * Todo list:
  45  * - Switch to gets() if $TERM is something we can't support.
  46  * - Filter bogus Ctrl+<char> combinations.
  47  * - Win32 support
  48  *
  49  * Bloat:
  50  * - Completion?
  51  * - History search like Ctrl+r in readline?
  52  *
  53  * List of escape sequences used by this program, we do everything just
  54  * with three sequences. In order to be so cheap we may have some
  55  * flickering effect with some slow terminal, but the lesser sequences
  56  * the more compatible.
  57  *
  58  * CHA (Cursor Horizontal Absolute)
  59  *    Sequence: ESC [ n G
  60  *    Effect: moves cursor to column n
  61  *
  62  * EL (Erase Line)
  63  *    Sequence: ESC [ n K
  64  *    Effect: if n is 0 or missing, clear from cursor to end of line
  65  *    Effect: if n is 1, clear from beginning of line to cursor
  66  *    Effect: if n is 2, clear entire line
  67  *
  68  * CUF (CUrsor Forward)
  69  *    Sequence: ESC [ n C
  70  *    Effect: moves cursor forward of n chars
  71  *
  72  * The following are used to clear the screen: ESC [ H ESC [ 2 J
  73  * This is actually composed of two sequences:
  74  *
  75  * cursorhome
  76  *    Sequence: ESC [ H
  77  *    Effect: moves the cursor to upper left corner
  78  *
  79  * ED2 (Clear entire screen)
  80  *    Sequence: ESC [ 2 J
  81  *    Effect: clear the whole screen
  82  *
  83  */
  84
  85 #include <termios.h>
  86 #include <unistd.h>
  87 #include <stdlib.h>
  88 #include <stdio.h>
  89 #include <errno.h>
  90 #include <string.h>
  91 #include <stdlib.h>
  92 #include <sys/types.h>
  93 #include <sys/ioctl.h>
  94 #include <unistd.h>
  95 #include "linenoise.h"
  96
  97 #define LINENOISE_DEFAULT_HISTORY_MAX_LEN 100
  98 #define LINENOISE_MAX_LINE 4096
  99 static char *unsupported_term[] = {"dumb","cons25",NULL};
 100 static linenoiseCompletionCallback *completionCallback = NULL;
 101
 102 static struct termios orig_termios; /* in order to restore at exit */
 103 static int rawmode = 0; /* for atexit() function to check if restore is needed*/
 104 static int atexit_registered = 0; /* register atexit just 1 time */
 105 static int history_max_len = LINENOISE_DEFAULT_HISTORY_MAX_LEN;
 106 static int history_len = 0;
 107 char **history = NULL;
 108
 109 static void linenoiseAtExit(void);
 110 int linenoiseHistoryAdd(const char *line);
 111
 112 static int isUnsupportedTerm(void) {
 113     char *term = getenv("TERM");
 114     int j;
 115
 116     if (term == NULL) return 0;
 117     for (j = 0; unsupported_term[j]; j++)
 118         if (!strcasecmp(term,unsupported_term[j])) return 1;
 119     return 0;
 120 }
 121
 122 static void freeHistory(void) {
 123     if (history) {
 124         int j;
 125
 126         for (j = 0; j < history_len; j++)
 127             free(history[j]);
 128         free(history);
 129     }
 130 }
 131
 132 static int enableRawMode(int fd) {
 133     struct termios raw;
 134
 135     if (!isatty(STDIN_FILENO)) goto fatal;
 136     if (!atexit_registered) {
 137         atexit(linenoiseAtExit);
 138         atexit_registered = 1;
 139     }
 140     if (tcgetattr(fd,&orig_termios) == -1) goto fatal;
 141
 142     raw = orig_termios;  /* modify the original mode */
 143     /* input modes: no break, no CR to NL, no parity check, no strip char,
 144      * no start/stop output control. */
 145     raw.c_iflag &= ~(BRKINT | ICRNL | INPCK | ISTRIP | IXON);
 146     /* output modes - disable post processing */
 147     raw.c_oflag &= ~(OPOST);
 148     /* control modes - set 8 bit chars */
 149     raw.c_cflag |= (CS8);
 150     /* local modes - choing off, canonical off, no extended functions,
 151      * no signal chars (^Z,^C) */
 152     raw.c_lflag &= ~(ECHO | ICANON | IEXTEN | ISIG);
 153     /* control chars - set return condition: min number of bytes and timer.
 154      * We want read to return every single byte, without timeout. */
 155     raw.c_cc[VMIN] = 1; raw.c_cc[VTIME] = 0; /* 1 byte, no timer */
 156
 157     /* put terminal in raw mode after flushing */
 158     if (tcsetattr(fd,TCSAFLUSH,&raw) < 0) goto fatal;
 159     rawmode = 1;
 160     return 0;
 161
 162 fatal:
 163     errno = ENOTTY;
 164     return -1;
 165 }
 166
 167 static void disableRawMode(int fd) {
 168     /* Don't even check the return value as it's too late. */
 169     if (rawmode && tcsetattr(fd,TCSAFLUSH,&orig_termios) != -1)
 170         rawmode = 0;
 171 }
 172
 173 /* At exit we'll try to fix the terminal to the initial conditions. */
 174 static void linenoiseAtExit(void) {
 175     disableRawMode(STDIN_FILENO);
 176     freeHistory();
 177 }
 178
 179 static int getColumns(void) {
 180     struct winsize ws;
 181
 182     if (ioctl(1, TIOCGWINSZ, &ws) == -1) return 80;
 183     return ws.ws_col;
 184 }
 185
 186 static void refreshLine(int fd, const char *prompt, char *buf, size_t len, size_t pos, size_t cols) {
 187     char seq[64];
 188     size_t plen = strlen(prompt);
 189
 190     while((plen+pos) >= cols) {
 191         buf++;
 192         len--;
 193         pos--;
 194     }
 195     while (plen+len > cols) {
 196         len--;
 197     }
 198
 199     /* Cursor to left edge */
 200     snprintf(seq,64,"\x1b[0G");
 201     if (write(fd,seq,strlen(seq)) == -1) return;
 202     /* Write the prompt and the current buffer content */
 203     if (write(fd,prompt,strlen(prompt)) == -1) return;
 204     if (write(fd,buf,len) == -1) return;
 205     /* Erase to right */
 206     snprintf(seq,64,"\x1b[0K");
 207     if (write(fd,seq,strlen(seq)) == -1) return;
 208     /* Move cursor to original position. */
 209     snprintf(seq,64,"\x1b[0G\x1b[%dC", (int)(pos+plen));
 210     if (write(fd,seq,strlen(seq)) == -1) return;
 211 }
 212
 213 static void beep() {
 214     fprintf(stderr, "\x7");
 215     fflush(stderr);
 216 }
 217
 218 static void freeCompletions(linenoiseCompletions *lc) {
 219     size_t i;
 220     for (i = 0; i < lc->len; i++)
 221         free(lc->cvec[i]);
 222     if (lc->cvec != NULL)
 223         free(lc->cvec);
 224 }
 225
 226 static int completeLine(int fd, const char *prompt, char *buf, size_t buflen, size_t *len, size_t *pos, size_t cols) {
 227     linenoiseCompletions lc = { 0, NULL };
 228     int nread, nwritten;
 229     char c = 0;
 230
 231     completionCallback(buf,&lc);
 232     if (lc.len == 0) {
 233         beep();
 234     } else {
 235         size_t stop = 0, i = 0;
 236         size_t clen;
 237
 238         while(!stop) {
 239             /* Show completion or original buffer */
 240             if (i < lc.len) {
 241                 clen = strlen(lc.cvec[i]);
 242                 refreshLine(fd,prompt,lc.cvec[i],clen,clen,cols);
 243             } else {
 244                 refreshLine(fd,prompt,buf,*len,*pos,cols);
 245             }
 246
 247             nread = read(fd,&c,1);
 248             if (nread <= 0) {
 249                 freeCompletions(&lc);
 250                 return -1;
 251             }
 252
 253             switch(c) {
 254                 case 9: /* tab */
 255                     i = (i+1) % (lc.len+1);
 256                     if (i == lc.len) beep();
 257                     break;
 258                 case 27: /* escape */
 259                     /* Re-show original buffer */
 260                     if (i < lc.len) {
 261                         refreshLine(fd,prompt,buf,*len,*pos,cols);
 262                     }
 263                     stop = 1;
 264                     break;
 265                 default:
 266                     /* Update buffer and return */
 267                     if (i < lc.len) {
 268                         nwritten = snprintf(buf,buflen,"%s",lc.cvec[i]);
 269                         *len = *pos = nwritten;
 270                     }
 271                     stop = 1;
 272                     break;
 273             }
 274         }
 275     }
 276
 277     freeCompletions(&lc);
 278     return c; /* Return last read character */
 279 }
 280
 281 void linenoiseClearScreen(void) {
 282     write(STDIN_FILENO,"\x1b[H\x1b[2J",7);
 283 }
 284
 285 static int linenoisePrompt(int fd, char *buf, size_t buflen, const char *prompt) {
 286     size_t plen = strlen(prompt);
 287     size_t pos = 0;
 288     size_t len = 0;
 289     size_t cols = getColumns();
 290     int history_index = 0;
 291
 292     buf[0] = '\0';
 293     buflen--; /* Make sure there is always space for the nulterm */
 294
 295     /* The latest history entry is always our current buffer, that
 296      * initially is just an empty string. */
 297     linenoiseHistoryAdd("");
 298
 299     if (write(fd,prompt,plen) == -1) return -1;
 300     while(1) {
 301         char c;
 302         int nread;
 303         char seq[2], seq2[2];
 304
 305         nread = read(fd,&c,1);
 306         if (nread <= 0) return len;
 307
 308         /* Only autocomplete when the callback is set. It returns < 0 when
 309          * there was an error reading from fd. Otherwise it will return the
 310          * character that should be handled next. */
 311         if (c == 9 && completionCallback != NULL) {
 312             c = completeLine(fd,prompt,buf,buflen,&len,&pos,cols);
 313             /* Return on errors */
 314             if (c < 0) return len;
 315             /* Read next character when 0 */
 316             if (c == 0) continue;
 317         }
 318
 319         switch(c) {
 320         case 13:    /* enter */
 321         case 4:     /* ctrl-d */
 322             history_len--;
 323             free(history[history_len]);
 324             return (len == 0 && c == 4) ? -1 : (int)len;
 325         case 3:     /* ctrl-c */
 326             errno = EAGAIN;
 327             return -1;
 328         case 127:   /* backspace */
 329         case 8:     /* ctrl-h */
 330             if (pos > 0 && len > 0) {
 331                 memmove(buf+pos-1,buf+pos,len-pos);
 332                 pos--;
 333                 len--;
 334                 buf[len] = '\0';
 335                 refreshLine(fd,prompt,buf,len,pos,cols);
 336             }
 337             break;
 338         case 20:    /* ctrl-t */
 339             if (pos > 0 && pos < len) {
 340                 int aux = buf[pos-1];
 341                 buf[pos-1] = buf[pos];
 342                 buf[pos] = aux;
 343                 if (pos != len-1) pos++;
 344                 refreshLine(fd,prompt,buf,len,pos,cols);
 345             }
 346             break;
 347         case 2:     /* ctrl-b */
 348             goto left_arrow;
 349         case 6:     /* ctrl-f */
 350             goto right_arrow;
 351         case 16:    /* ctrl-p */
 352             seq[1] = 65;
 353             goto up_down_arrow;
 354         case 14:    /* ctrl-n */
 355             seq[1] = 66;
 356             goto up_down_arrow;
 357             break;
 358         case 27:    /* escape sequence */
 359             if (read(fd,seq,2) == -1) break;
 360             if (seq[0] == 91 && seq[1] == 68) {
 361 left_arrow:
 362                 /* left arrow */
 363                 if (pos > 0) {
 364                     pos--;
 365                     refreshLine(fd,prompt,buf,len,pos,cols);
 366                 }
 367             } else if (seq[0] == 91 && seq[1] == 67) {
 368 right_arrow:
 369                 /* right arrow */
 370                 if (pos != len) {
 371                     pos++;
 372                     refreshLine(fd,prompt,buf,len,pos,cols);
 373                 }
 374             } else if (seq[0] == 91 && (seq[1] == 65 || seq[1] == 66)) {
 375 up_down_arrow:
 376                 /* up and down arrow: history */
 377                 if (history_len > 1) {
 378                     /* Update the current history entry before to
 379                      * overwrite it with tne next one. */
 380                     free(history[history_len-1-history_index]);
 381                     history[history_len-1-history_index] = strdup(buf);
 382                     /* Show the new entry */
 383                     history_index += (seq[1] == 65) ? 1 : -1;
 384                     if (history_index < 0) {
 385                         history_index = 0;
 386                         break;
 387                     } else if (history_index >= history_len) {
 388                         history_index = history_len-1;
 389                         break;
 390                     }
 391                     strncpy(buf,history[history_len-1-history_index],buflen);
 392                     buf[buflen] = '\0';
 393                     len = pos = strlen(buf);
 394                     refreshLine(fd,prompt,buf,len,pos,cols);
 395                 }
 396             } else if (seq[0] == 91 && seq[1] > 48 && seq[1] < 55) {
 397                 /* extended escape */
 398                 if (read(fd,seq2,2) == -1) break;
 399                 if (seq[1] == 51 && seq2[0] == 126) {
 400                     /* delete */
 401                     if (len > 0 && pos < len) {
 402                         memmove(buf+pos,buf+pos+1,len-pos-1);
 403                         len--;
 404                         buf[len] = '\0';
 405                         refreshLine(fd,prompt,buf,len,pos,cols);
 406                     }
 407                 }
 408             }
 409             break;
 410         default:
 411             if (len < buflen) {
 412                 if (len == pos) {
 413                     buf[pos] = c;
 414                     pos++;
 415                     len++;
 416                     buf[len] = '\0';
 417                     if (plen+len < cols) {
 418                         /* Avoid a full update of the line in the
 419                          * trivial case. */
 420                         if (write(fd,&c,1) == -1) return -1;
 421                     } else {
 422                         refreshLine(fd,prompt,buf,len,pos,cols);
 423                     }
 424                 } else {
 425                     memmove(buf+pos+1,buf+pos,len-pos);
 426                     buf[pos] = c;
 427                     len++;
 428                     pos++;
 429                     buf[len] = '\0';
 430                     refreshLine(fd,prompt,buf,len,pos,cols);
 431                 }
 432             }
 433             break;
 434         case 21: /* Ctrl+u, delete the whole line. */
 435             buf[0] = '\0';
 436             pos = len = 0;
 437             refreshLine(fd,prompt,buf,len,pos,cols);
 438             break;
 439         case 11: /* Ctrl+k, delete from current to end of line. */
 440             buf[pos] = '\0';
 441             len = pos;
 442             refreshLine(fd,prompt,buf,len,pos,cols);
 443             break;
 444         case 1: /* Ctrl+a, go to the start of the line */
 445             pos = 0;
 446             refreshLine(fd,prompt,buf,len,pos,cols);
 447             break;
 448         case 5: /* ctrl+e, go to the end of the line */
 449             pos = len;
 450             refreshLine(fd,prompt,buf,len,pos,cols);
 451             break;
 452         case 12: /* ctrl+l, clear screen */
 453             linenoiseClearScreen();
 454             refreshLine(fd,prompt,buf,len,pos,cols);
 455         }
 456     }
 457     return len;
 458 }
 459
 460 static int linenoiseRaw(char *buf, size_t buflen, const char *prompt) {
 461     int fd = STDIN_FILENO;
 462     int count;
 463
 464     if (buflen == 0) {
 465         errno = EINVAL;
 466         return -1;
 467     }
 468     if (!isatty(STDIN_FILENO)) {
 469         if (fgets(buf, buflen, stdin) == NULL) return -1;
 470         count = strlen(buf);
 471         if (count && buf[count-1] == '\n') {
 472             count--;
 473             buf[count] = '\0';
 474         }
 475     } else {
 476         if (enableRawMode(fd) == -1) return -1;
 477         count = linenoisePrompt(fd, buf, buflen, prompt);
 478         disableRawMode(fd);
 479         printf("\n");
 480     }
 481     return count;
 482 }
 483
 484 char *linenoise(const char *prompt) {
 485     char buf[LINENOISE_MAX_LINE];
 486     int count;
 487
 488     if (isUnsupportedTerm()) {
 489         size_t len;
 490
 491         printf("%s",prompt);
 492         fflush(stdout);
 493         if (fgets(buf,LINENOISE_MAX_LINE,stdin) == NULL) return NULL;
 494         len = strlen(buf);
 495         while(len && (buf[len-1] == '\n' || buf[len-1] == '\r')) {
 496             len--;
 497             buf[len] = '\0';
 498         }
 499         return strdup(buf);
 500     } else {
 501         count = linenoiseRaw(buf,LINENOISE_MAX_LINE,prompt);
 502         if (count == -1) return NULL;
 503         return strdup(buf);
 504     }
 505 }
 506
 507 /* Register a callback function to be called for tab-completion. */
 508 void linenoiseSetCompletionCallback(linenoiseCompletionCallback *fn) {
 509     completionCallback = fn;
 510 }
 511
 512 void linenoiseAddCompletion(linenoiseCompletions *lc, char *str) {
 513     size_t len = strlen(str);
 514     char *copy = malloc(len+1);
 515     memcpy(copy,str,len+1);
 516     lc->cvec = realloc(lc->cvec,sizeof(char*)*(lc->len+1));
 517     lc->cvec[lc->len++] = copy;
 518 }
 519
 520 /* Using a circular buffer is smarter, but a bit more complex to handle. */
 521 int linenoiseHistoryAdd(const char *line) {
 522     char *linecopy;
 523
 524     if (history_max_len == 0) return 0;
 525     if (history == NULL) {
 526         history = malloc(sizeof(char*)*history_max_len);
 527         if (history == NULL) return 0;
 528         memset(history,0,(sizeof(char*)*history_max_len));
 529     }
 530     linecopy = strdup(line);
 531     if (!linecopy) return 0;
 532     if (history_len == history_max_len) {
 533         free(history[0]);
 534         memmove(history,history+1,sizeof(char*)*(history_max_len-1));
 535         history_len--;
 536     }
 537     history[history_len] = linecopy;
 538     history_len++;
 539     return 1;
 540 }
 541
 542 int linenoiseHistorySetMaxLen(int len) {
 543     char **new;
 544
 545     if (len < 1) return 0;
 546     if (history) {
 547         int tocopy = history_len;
 548
 549         new = malloc(sizeof(char*)*len);
 550         if (new == NULL) return 0;
 551         if (len < tocopy) tocopy = len;
 552         memcpy(new,history+(history_max_len-tocopy), sizeof(char*)*tocopy);
 553         free(history);
 554         history = new;
 555     }
 556     history_max_len = len;
 557     if (history_len > history_max_len)
 558         history_len = history_max_len;
 559     return 1;
 560 }
 561
 562 /* Save the history in the specified file. On success 0 is returned
 563  * otherwise -1 is returned. */
 564 int linenoiseHistorySave(char *filename) {
 565     FILE *fp = fopen(filename,"w");
 566     int j;
 567
 568     if (fp == NULL) return -1;
 569     for (j = 0; j < history_len; j++)
 570         fprintf(fp,"%s\n",history[j]);
 571     fclose(fp);
 572     return 0;
 573 }
 574
 575 /* Load the history from the specified file. If the file does not exist
 576  * zero is returned and no operation is performed.
 577  *
 578  * If the file exists and the operation succeeded 0 is returned, otherwise
 579  * on error -1 is returned. */
 580 int linenoiseHistoryLoad(char *filename) {
 581     FILE *fp = fopen(filename,"r");
 582     char buf[LINENOISE_MAX_LINE];
 583
 584     if (fp == NULL) return -1;
 585
 586     while (fgets(buf,LINENOISE_MAX_LINE,fp) != NULL) {
 587         char *p;
 588
 589         p = strchr(buf,'\r');
 590         if (!p) p = strchr(buf,'\n');
 591         if (p) *p = '\0';
 592         linenoiseHistoryAdd(buf);
 593     }
 594     fclose(fp);
 595     return 0;
 596 }