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     if (write(STDIN_FILENO,"\x1b[H\x1b[2J",7) <= 0) {
 283         /* nothing to do, just to avoid warning. */
 284     }
 285 }
 286
 287 static int linenoisePrompt(int fd, char *buf, size_t buflen, const char *prompt) {
 288     size_t plen = strlen(prompt);
 289     size_t pos = 0;
 290     size_t len = 0;
 291     size_t cols = getColumns();
 292     int history_index = 0;
 293
 294     buf[0] = '\0';
 295     buflen--; /* Make sure there is always space for the nulterm */
 296
 297     /* The latest history entry is always our current buffer, that
 298      * initially is just an empty string. */
 299     linenoiseHistoryAdd("");
 300
 301     if (write(fd,prompt,plen) == -1) return -1;
 302     while(1) {
 303         char c;
 304         int nread;
 305         char seq[2], seq2[2];
 306
 307         nread = read(fd,&c,1);
 308         if (nread <= 0) return len;
 309
 310         /* Only autocomplete when the callback is set. It returns < 0 when
 311          * there was an error reading from fd. Otherwise it will return the
 312          * character that should be handled next. */
 313         if (c == 9 && completionCallback != NULL) {
 314             c = completeLine(fd,prompt,buf,buflen,&len,&pos,cols);
 315             /* Return on errors */
 316             if (c < 0) return len;
 317             /* Read next character when 0 */
 318             if (c == 0) continue;
 319         }
 320
 321         switch(c) {
 322         case 13:    /* enter */
 323         case 4:     /* ctrl-d */
 324             history_len--;
 325             free(history[history_len]);
 326             return (len == 0 && c == 4) ? -1 : (int)len;
 327         case 3:     /* ctrl-c */
 328             errno = EAGAIN;
 329             return -1;
 330         case 127:   /* backspace */
 331         case 8:     /* ctrl-h */
 332             if (pos > 0 && len > 0) {
 333                 memmove(buf+pos-1,buf+pos,len-pos);
 334                 pos--;
 335                 len--;
 336                 buf[len] = '\0';
 337                 refreshLine(fd,prompt,buf,len,pos,cols);
 338             }
 339             break;
 340         case 20:    /* ctrl-t */
 341             if (pos > 0 && pos < len) {
 342                 int aux = buf[pos-1];
 343                 buf[pos-1] = buf[pos];
 344                 buf[pos] = aux;
 345                 if (pos != len-1) pos++;
 346                 refreshLine(fd,prompt,buf,len,pos,cols);
 347             }
 348             break;
 349         case 2:     /* ctrl-b */
 350             goto left_arrow;
 351         case 6:     /* ctrl-f */
 352             goto right_arrow;
 353         case 16:    /* ctrl-p */
 354             seq[1] = 65;
 355             goto up_down_arrow;
 356         case 14:    /* ctrl-n */
 357             seq[1] = 66;
 358             goto up_down_arrow;
 359             break;
 360         case 27:    /* escape sequence */
 361             if (read(fd,seq,2) == -1) break;
 362             if (seq[0] == 91 && seq[1] == 68) {
 363 left_arrow:
 364                 /* left arrow */
 365                 if (pos > 0) {
 366                     pos--;
 367                     refreshLine(fd,prompt,buf,len,pos,cols);
 368                 }
 369             } else if (seq[0] == 91 && seq[1] == 67) {
 370 right_arrow:
 371                 /* right arrow */
 372                 if (pos != len) {
 373                     pos++;
 374                     refreshLine(fd,prompt,buf,len,pos,cols);
 375                 }
 376             } else if (seq[0] == 91 && (seq[1] == 65 || seq[1] == 66)) {
 377 up_down_arrow:
 378                 /* up and down arrow: history */
 379                 if (history_len > 1) {
 380                     /* Update the current history entry before to
 381                      * overwrite it with tne next one. */
 382                     free(history[history_len-1-history_index]);
 383                     history[history_len-1-history_index] = strdup(buf);
 384                     /* Show the new entry */
 385                     history_index += (seq[1] == 65) ? 1 : -1;
 386                     if (history_index < 0) {
 387                         history_index = 0;
 388                         break;
 389                     } else if (history_index >= history_len) {
 390                         history_index = history_len-1;
 391                         break;
 392                     }
 393                     strncpy(buf,history[history_len-1-history_index],buflen);
 394                     buf[buflen] = '\0';
 395                     len = pos = strlen(buf);
 396                     refreshLine(fd,prompt,buf,len,pos,cols);
 397                 }
 398             } else if (seq[0] == 91 && seq[1] > 48 && seq[1] < 55) {
 399                 /* extended escape */
 400                 if (read(fd,seq2,2) == -1) break;
 401                 if (seq[1] == 51 && seq2[0] == 126) {
 402                     /* delete */
 403                     if (len > 0 && pos < len) {
 404                         memmove(buf+pos,buf+pos+1,len-pos-1);
 405                         len--;
 406                         buf[len] = '\0';
 407                         refreshLine(fd,prompt,buf,len,pos,cols);
 408                     }
 409                 }
 410             }
 411             break;
 412         default:
 413             if (len < buflen) {
 414                 if (len == pos) {
 415                     buf[pos] = c;
 416                     pos++;
 417                     len++;
 418                     buf[len] = '\0';
 419                     if (plen+len < cols) {
 420                         /* Avoid a full update of the line in the
 421                          * trivial case. */
 422                         if (write(fd,&c,1) == -1) return -1;
 423                     } else {
 424                         refreshLine(fd,prompt,buf,len,pos,cols);
 425                     }
 426                 } else {
 427                     memmove(buf+pos+1,buf+pos,len-pos);
 428                     buf[pos] = c;
 429                     len++;
 430                     pos++;
 431                     buf[len] = '\0';
 432                     refreshLine(fd,prompt,buf,len,pos,cols);
 433                 }
 434             }
 435             break;
 436         case 21: /* Ctrl+u, delete the whole line. */
 437             buf[0] = '\0';
 438             pos = len = 0;
 439             refreshLine(fd,prompt,buf,len,pos,cols);
 440             break;
 441         case 11: /* Ctrl+k, delete from current to end of line. */
 442             buf[pos] = '\0';
 443             len = pos;
 444             refreshLine(fd,prompt,buf,len,pos,cols);
 445             break;
 446         case 1: /* Ctrl+a, go to the start of the line */
 447             pos = 0;
 448             refreshLine(fd,prompt,buf,len,pos,cols);
 449             break;
 450         case 5: /* ctrl+e, go to the end of the line */
 451             pos = len;
 452             refreshLine(fd,prompt,buf,len,pos,cols);
 453             break;
 454         case 12: /* ctrl+l, clear screen */
 455             linenoiseClearScreen();
 456             refreshLine(fd,prompt,buf,len,pos,cols);
 457         }
 458     }
 459     return len;
 460 }
 461
 462 static int linenoiseRaw(char *buf, size_t buflen, const char *prompt) {
 463     int fd = STDIN_FILENO;
 464     int count;
 465
 466     if (buflen == 0) {
 467         errno = EINVAL;
 468         return -1;
 469     }
 470     if (!isatty(STDIN_FILENO)) {
 471         if (fgets(buf, buflen, stdin) == NULL) return -1;
 472         count = strlen(buf);
 473         if (count && buf[count-1] == '\n') {
 474             count--;
 475             buf[count] = '\0';
 476         }
 477     } else {
 478         if (enableRawMode(fd) == -1) return -1;
 479         count = linenoisePrompt(fd, buf, buflen, prompt);
 480         disableRawMode(fd);
 481         printf("\n");
 482     }
 483     return count;
 484 }
 485
 486 char *linenoise(const char *prompt) {
 487     char buf[LINENOISE_MAX_LINE];
 488     int count;
 489
 490     if (isUnsupportedTerm()) {
 491         size_t len;
 492
 493         printf("%s",prompt);
 494         fflush(stdout);
 495         if (fgets(buf,LINENOISE_MAX_LINE,stdin) == NULL) return NULL;
 496         len = strlen(buf);
 497         while(len && (buf[len-1] == '\n' || buf[len-1] == '\r')) {
 498             len--;
 499             buf[len] = '\0';
 500         }
 501         return strdup(buf);
 502     } else {
 503         count = linenoiseRaw(buf,LINENOISE_MAX_LINE,prompt);
 504         if (count == -1) return NULL;
 505         return strdup(buf);
 506     }
 507 }
 508
 509 /* Register a callback function to be called for tab-completion. */
 510 void linenoiseSetCompletionCallback(linenoiseCompletionCallback *fn) {
 511     completionCallback = fn;
 512 }
 513
 514 void linenoiseAddCompletion(linenoiseCompletions *lc, char *str) {
 515     size_t len = strlen(str);
 516     char *copy = malloc(len+1);
 517     memcpy(copy,str,len+1);
 518     lc->cvec = realloc(lc->cvec,sizeof(char*)*(lc->len+1));
 519     lc->cvec[lc->len++] = copy;
 520 }
 521
 522 /* Using a circular buffer is smarter, but a bit more complex to handle. */
 523 int linenoiseHistoryAdd(const char *line) {
 524     char *linecopy;
 525
 526     if (history_max_len == 0) return 0;
 527     if (history == NULL) {
 528         history = malloc(sizeof(char*)*history_max_len);
 529         if (history == NULL) return 0;
 530         memset(history,0,(sizeof(char*)*history_max_len));
 531     }
 532     linecopy = strdup(line);
 533     if (!linecopy) return 0;
 534     if (history_len == history_max_len) {
 535         free(history[0]);
 536         memmove(history,history+1,sizeof(char*)*(history_max_len-1));
 537         history_len--;
 538     }
 539     history[history_len] = linecopy;
 540     history_len++;
 541     return 1;
 542 }
 543
 544 int linenoiseHistorySetMaxLen(int len) {
 545     char **new;
 546
 547     if (len < 1) return 0;
 548     if (history) {
 549         int tocopy = history_len;
 550
 551         new = malloc(sizeof(char*)*len);
 552         if (new == NULL) return 0;
 553         if (len < tocopy) tocopy = len;
 554         memcpy(new,history+(history_max_len-tocopy), sizeof(char*)*tocopy);
 555         free(history);
 556         history = new;
 557     }
 558     history_max_len = len;
 559     if (history_len > history_max_len)
 560         history_len = history_max_len;
 561     return 1;
 562 }
 563
 564 /* Save the history in the specified file. On success 0 is returned
 565  * otherwise -1 is returned. */
 566 int linenoiseHistorySave(char *filename) {
 567     FILE *fp = fopen(filename,"w");
 568     int j;
 569
 570     if (fp == NULL) return -1;
 571     for (j = 0; j < history_len; j++)
 572         fprintf(fp,"%s\n",history[j]);
 573     fclose(fp);
 574     return 0;
 575 }
 576
 577 /* Load the history from the specified file. If the file does not exist
 578  * zero is returned and no operation is performed.
 579  *
 580  * If the file exists and the operation succeeded 0 is returned, otherwise
 581  * on error -1 is returned. */
 582 int linenoiseHistoryLoad(char *filename) {
 583     FILE *fp = fopen(filename,"r");
 584     char buf[LINENOISE_MAX_LINE];
 585
 586     if (fp == NULL) return -1;
 587
 588     while (fgets(buf,LINENOISE_MAX_LINE,fp) != NULL) {
 589         char *p;
 590
 591         p = strchr(buf,'\r');
 592         if (!p) p = strchr(buf,'\n');
 593         if (p) *p = '\0';
 594         linenoiseHistoryAdd(buf);
 595     }
 596     fclose(fp);
 597     return 0;
 598 }