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  * ------------------------------------------------------------------------
  12  *
  13  * Copyright (c) 2010, Salvatore Sanfilippo <antirez at gmail dot com>
  14  * Copyright (c) 2010, Pieter Noordhuis <pcnoordhuis at gmail dot com>
  15  *
  16  * All rights reserved.
  17  *
  18  * Redistribution and use in source and binary forms, with or without
  19  * modification, are permitted provided that the following conditions are
  20  * met:
  21  *
  22  *  *  Redistributions of source code must retain the above copyright
  23  *     notice, this list of conditions and the following disclaimer.
  24  *
  25  *  *  Redistributions in binary form must reproduce the above copyright
  26  *     notice, this list of conditions and the following disclaimer in the
  27  *     documentation and/or other materials provided with the distribution.
  28  *
  29  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  30  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  31  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  32  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  33  * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  34  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  35  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  36  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  37  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  38  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  39  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  40  *
  41  * ------------------------------------------------------------------------
  42  *
  43  * References:
  44  * - http://invisible-island.net/xterm/ctlseqs/ctlseqs.html
  45  * - http://www.3waylabs.com/nw/WWW/products/wizcon/vt220.html
  46  *
  47  * Todo list:
  48  * - Switch to gets() if $TERM is something we can't support.
  49  * - Filter bogus Ctrl+<char> combinations.
  50  * - Win32 support
  51  *
  52  * Bloat:
  53  * - Completion?
  54  * - History search like Ctrl+r in readline?
  55  *
  56  * List of escape sequences used by this program, we do everything just
  57  * with three sequences. In order to be so cheap we may have some
  58  * flickering effect with some slow terminal, but the lesser sequences
  59  * the more compatible.
  60  *
  61  * CHA (Cursor Horizontal Absolute)
  62  *    Sequence: ESC [ n G
  63  *    Effect: moves cursor to column n
  64  *
  65  * EL (Erase Line)
  66  *    Sequence: ESC [ n K
  67  *    Effect: if n is 0 or missing, clear from cursor to end of line
  68  *    Effect: if n is 1, clear from beginning of line to cursor
  69  *    Effect: if n is 2, clear entire line
  70  *
  71  * CUF (CUrsor Forward)
  72  *    Sequence: ESC [ n C
  73  *    Effect: moves cursor forward of n chars
  74  *
  75  * The following are used to clear the screen: ESC [ H ESC [ 2 J
  76  * This is actually composed of two sequences:
  77  *
  78  * cursorhome
  79  *    Sequence: ESC [ H
  80  *    Effect: moves the cursor to upper left corner
  81  *
  82  * ED2 (Clear entire screen)
  83  *    Sequence: ESC [ 2 J
  84  *    Effect: clear the whole screen
  85  *
  86  */
  87
  88 #include <termios.h>
  89 #include <unistd.h>
  90 #include <stdlib.h>
  91 #include <stdio.h>
  92 #include <errno.h>
  93 #include <string.h>
  94 #include <stdlib.h>
  95 #include <sys/types.h>
  96 #include <sys/ioctl.h>
  97 #include <unistd.h>
  98 #include "linenoise.h"
  99
 100 #define LINENOISE_DEFAULT_HISTORY_MAX_LEN 100
 101 #define LINENOISE_MAX_LINE 4096
 102 static char *unsupported_term[] = {"dumb","cons25",NULL};
 103 static linenoiseCompletionCallback *completionCallback = NULL;
 104
 105 static struct termios orig_termios; /* in order to restore at exit */
 106 static int rawmode = 0; /* for atexit() function to check if restore is needed*/
 107 static int atexit_registered = 0; /* register atexit just 1 time */
 108 static int history_max_len = LINENOISE_DEFAULT_HISTORY_MAX_LEN;
 109 static int history_len = 0;
 110 char **history = NULL;
 111
 112 static void linenoiseAtExit(void);
 113 int linenoiseHistoryAdd(const char *line);
 114
 115 static int isUnsupportedTerm(void) {
 116     char *term = getenv("TERM");
 117     int j;
 118
 119     if (term == NULL) return 0;
 120     for (j = 0; unsupported_term[j]; j++)
 121         if (!strcasecmp(term,unsupported_term[j])) return 1;
 122     return 0;
 123 }
 124
 125 static void freeHistory(void) {
 126     if (history) {
 127         int j;
 128
 129         for (j = 0; j < history_len; j++)
 130             free(history[j]);
 131         free(history);
 132     }
 133 }
 134
 135 static int enableRawMode(int fd) {
 136     struct termios raw;
 137
 138     if (!isatty(STDIN_FILENO)) goto fatal;
 139     if (!atexit_registered) {
 140         atexit(linenoiseAtExit);
 141         atexit_registered = 1;
 142     }
 143     if (tcgetattr(fd,&orig_termios) == -1) goto fatal;
 144
 145     raw = orig_termios;  /* modify the original mode */
 146     /* input modes: no break, no CR to NL, no parity check, no strip char,
 147      * no start/stop output control. */
 148     raw.c_iflag &= ~(BRKINT | ICRNL | INPCK | ISTRIP | IXON);
 149     /* output modes - disable post processing */
 150     raw.c_oflag &= ~(OPOST);
 151     /* control modes - set 8 bit chars */
 152     raw.c_cflag |= (CS8);
 153     /* local modes - choing off, canonical off, no extended functions,
 154      * no signal chars (^Z,^C) */
 155     raw.c_lflag &= ~(ECHO | ICANON | IEXTEN | ISIG);
 156     /* control chars - set return condition: min number of bytes and timer.
 157      * We want read to return every single byte, without timeout. */
 158     raw.c_cc[VMIN] = 1; raw.c_cc[VTIME] = 0; /* 1 byte, no timer */
 159
 160     /* put terminal in raw mode after flushing */
 161     if (tcsetattr(fd,TCSAFLUSH,&raw) < 0) goto fatal;
 162     rawmode = 1;
 163     return 0;
 164
 165 fatal:
 166     errno = ENOTTY;
 167     return -1;
 168 }
 169
 170 static void disableRawMode(int fd) {
 171     /* Don't even check the return value as it's too late. */
 172     if (rawmode && tcsetattr(fd,TCSAFLUSH,&orig_termios) != -1)
 173         rawmode = 0;
 174 }
 175
 176 /* At exit we'll try to fix the terminal to the initial conditions. */
 177 static void linenoiseAtExit(void) {
 178     disableRawMode(STDIN_FILENO);
 179     freeHistory();
 180 }
 181
 182 static int getColumns(void) {
 183     struct winsize ws;
 184
 185     if (ioctl(1, TIOCGWINSZ, &ws) == -1) return 80;
 186     return ws.ws_col;
 187 }
 188
 189 static void refreshLine(int fd, const char *prompt, char *buf, size_t len, size_t pos, size_t cols) {
 190     char seq[64];
 191     size_t plen = strlen(prompt);
 192
 193     while((plen+pos) >= cols) {
 194         buf++;
 195         len--;
 196         pos--;
 197     }
 198     while (plen+len > cols) {
 199         len--;
 200     }
 201
 202     /* Cursor to left edge */
 203     snprintf(seq,64,"\x1b[0G");
 204     if (write(fd,seq,strlen(seq)) == -1) return;
 205     /* Write the prompt and the current buffer content */
 206     if (write(fd,prompt,strlen(prompt)) == -1) return;
 207     if (write(fd,buf,len) == -1) return;
 208     /* Erase to right */
 209     snprintf(seq,64,"\x1b[0K");
 210     if (write(fd,seq,strlen(seq)) == -1) return;
 211     /* Move cursor to original position. */
 212     snprintf(seq,64,"\x1b[0G\x1b[%dC", (int)(pos+plen));
 213     if (write(fd,seq,strlen(seq)) == -1) return;
 214 }
 215
 216 static void beep() {
 217     fprintf(stderr, "\x7");
 218     fflush(stderr);
 219 }
 220
 221 static void freeCompletions(linenoiseCompletions *lc) {
 222     size_t i;
 223     for (i = 0; i < lc->len; i++)
 224         free(lc->cvec[i]);
 225     if (lc->cvec != NULL)
 226         free(lc->cvec);
 227 }
 228
 229 static int completeLine(int fd, const char *prompt, char *buf, size_t buflen, size_t *len, size_t *pos, size_t cols) {
 230     linenoiseCompletions lc = { 0, NULL };
 231     int nread, nwritten;
 232     char c = 0;
 233
 234     completionCallback(buf,&lc);
 235     if (lc.len == 0) {
 236         beep();
 237     } else {
 238         size_t stop = 0, i = 0;
 239         size_t clen;
 240
 241         while(!stop) {
 242             /* Show completion or original buffer */
 243             if (i < lc.len) {
 244                 clen = strlen(lc.cvec[i]);
 245                 refreshLine(fd,prompt,lc.cvec[i],clen,clen,cols);
 246             } else {
 247                 refreshLine(fd,prompt,buf,*len,*pos,cols);
 248             }
 249
 250             nread = read(fd,&c,1);
 251             if (nread <= 0) {
 252                 freeCompletions(&lc);
 253                 return -1;
 254             }
 255
 256             switch(c) {
 257                 case 9: /* tab */
 258                     i = (i+1) % (lc.len+1);
 259                     if (i == lc.len) beep();
 260                     break;
 261                 case 27: /* escape */
 262                     /* Re-show original buffer */
 263                     if (i < lc.len) {
 264                         refreshLine(fd,prompt,buf,*len,*pos,cols);
 265                     }
 266                     stop = 1;
 267                     break;
 268                 default:
 269                     /* Update buffer and return */
 270                     if (i < lc.len) {
 271                         nwritten = snprintf(buf,buflen,"%s",lc.cvec[i]);
 272                         *len = *pos = nwritten;
 273                     }
 274                     stop = 1;
 275                     break;
 276             }
 277         }
 278     }
 279
 280     freeCompletions(&lc);
 281     return c; /* Return last read character */
 282 }
 283
 284 void linenoiseClearScreen(void) {
 285     if (write(STDIN_FILENO,"\x1b[H\x1b[2J",7) <= 0) {
 286         /* nothing to do, just to avoid warning. */
 287     }
 288 }
 289
 290 static int linenoisePrompt(int fd, char *buf, size_t buflen, const char *prompt) {
 291     size_t plen = strlen(prompt);
 292     size_t pos = 0;
 293     size_t len = 0;
 294     size_t cols = getColumns();
 295     int history_index = 0;
 296     size_t old_pos;
 297     size_t diff;
 298
 299     buf[0] = '\0';
 300     buflen--; /* Make sure there is always space for the nulterm */
 301
 302     /* The latest history entry is always our current buffer, that
 303      * initially is just an empty string. */
 304     linenoiseHistoryAdd("");
 305
 306     if (write(fd,prompt,plen) == -1) return -1;
 307     while(1) {
 308         char c;
 309         int nread;
 310         char seq[2], seq2[2];
 311
 312         nread = read(fd,&c,1);
 313         if (nread <= 0) return len;
 314
 315         /* Only autocomplete when the callback is set. It returns < 0 when
 316          * there was an error reading from fd. Otherwise it will return the
 317          * character that should be handled next. */
 318         if (c == 9 && completionCallback != NULL) {
 319             c = completeLine(fd,prompt,buf,buflen,&len,&pos,cols);
 320             /* Return on errors */
 321             if (c < 0) return len;
 322             /* Read next character when 0 */
 323             if (c == 0) continue;
 324         }
 325
 326         switch(c) {
 327         case 13:    /* enter */
 328             history_len--;
 329             free(history[history_len]);
 330             return (int)len;
 331         case 3:     /* ctrl-c */
 332             errno = EAGAIN;
 333             return -1;
 334         case 127:   /* backspace */
 335         case 8:     /* ctrl-h */
 336             if (pos > 0 && len > 0) {
 337                 memmove(buf+pos-1,buf+pos,len-pos);
 338                 pos--;
 339                 len--;
 340                 buf[len] = '\0';
 341                 refreshLine(fd,prompt,buf,len,pos,cols);
 342             }
 343             break;
 344         case 4:     /* ctrl-d, remove char at right of cursor */
 345             if (len > 1 && pos < (len-1)) {
 346                 memmove(buf+pos,buf+pos+1,len-pos);
 347                 len--;
 348                 buf[len] = '\0';
 349                 refreshLine(fd,prompt,buf,len,pos,cols);
 350             } else if (len == 0) {
 351                 history_len--;
 352                 free(history[history_len]);
 353                 return -1;
 354             }
 355             break;
 356         case 20:    /* ctrl-t */
 357             if (pos > 0 && pos < len) {
 358                 int aux = buf[pos-1];
 359                 buf[pos-1] = buf[pos];
 360                 buf[pos] = aux;
 361                 if (pos != len-1) pos++;
 362                 refreshLine(fd,prompt,buf,len,pos,cols);
 363             }
 364             break;
 365         case 2:     /* ctrl-b */
 366             goto left_arrow;
 367         case 6:     /* ctrl-f */
 368             goto right_arrow;
 369         case 16:    /* ctrl-p */
 370             seq[1] = 65;
 371             goto up_down_arrow;
 372         case 14:    /* ctrl-n */
 373             seq[1] = 66;
 374             goto up_down_arrow;
 375             break;
 376         case 27:    /* escape sequence */
 377             if (read(fd,seq,2) == -1) break;
 378             if (seq[0] == 91 && seq[1] == 68) {
 379 left_arrow:
 380                 /* left arrow */
 381                 if (pos > 0) {
 382                     pos--;
 383                     refreshLine(fd,prompt,buf,len,pos,cols);
 384                 }
 385             } else if (seq[0] == 91 && seq[1] == 67) {
 386 right_arrow:
 387                 /* right arrow */
 388                 if (pos != len) {
 389                     pos++;
 390                     refreshLine(fd,prompt,buf,len,pos,cols);
 391                 }
 392             } else if (seq[0] == 91 && (seq[1] == 65 || seq[1] == 66)) {
 393 up_down_arrow:
 394                 /* up and down arrow: history */
 395                 if (history_len > 1) {
 396                     /* Update the current history entry before to
 397                      * overwrite it with tne next one. */
 398                     free(history[history_len-1-history_index]);
 399                     history[history_len-1-history_index] = strdup(buf);
 400                     /* Show the new entry */
 401                     history_index += (seq[1] == 65) ? 1 : -1;
 402                     if (history_index < 0) {
 403                         history_index = 0;
 404                         break;
 405                     } else if (history_index >= history_len) {
 406                         history_index = history_len-1;
 407                         break;
 408                     }
 409                     strncpy(buf,history[history_len-1-history_index],buflen);
 410                     buf[buflen] = '\0';
 411                     len = pos = strlen(buf);
 412                     refreshLine(fd,prompt,buf,len,pos,cols);
 413                 }
 414             } else if (seq[0] == 91 && seq[1] > 48 && seq[1] < 55) {
 415                 /* extended escape */
 416                 if (read(fd,seq2,2) == -1) break;
 417                 if (seq[1] == 51 && seq2[0] == 126) {
 418                     /* delete */
 419                     if (len > 0 && pos < len) {
 420                         memmove(buf+pos,buf+pos+1,len-pos-1);
 421                         len--;
 422                         buf[len] = '\0';
 423                         refreshLine(fd,prompt,buf,len,pos,cols);
 424                     }
 425                 }
 426             }
 427             break;
 428         default:
 429             if (len < buflen) {
 430                 if (len == pos) {
 431                     buf[pos] = c;
 432                     pos++;
 433                     len++;
 434                     buf[len] = '\0';
 435                     if (plen+len < cols) {
 436                         /* Avoid a full update of the line in the
 437                          * trivial case. */
 438                         if (write(fd,&c,1) == -1) return -1;
 439                     } else {
 440                         refreshLine(fd,prompt,buf,len,pos,cols);
 441                     }
 442                 } else {
 443                     memmove(buf+pos+1,buf+pos,len-pos);
 444                     buf[pos] = c;
 445                     len++;
 446                     pos++;
 447                     buf[len] = '\0';
 448                     refreshLine(fd,prompt,buf,len,pos,cols);
 449                 }
 450             }
 451             break;
 452         case 21: /* Ctrl+u, delete the whole line. */
 453             buf[0] = '\0';
 454             pos = len = 0;
 455             refreshLine(fd,prompt,buf,len,pos,cols);
 456             break;
 457         case 11: /* Ctrl+k, delete from current to end of line. */
 458             buf[pos] = '\0';
 459             len = pos;
 460             refreshLine(fd,prompt,buf,len,pos,cols);
 461             break;
 462         case 1: /* Ctrl+a, go to the start of the line */
 463             pos = 0;
 464             refreshLine(fd,prompt,buf,len,pos,cols);
 465             break;
 466         case 5: /* ctrl+e, go to the end of the line */
 467             pos = len;
 468             refreshLine(fd,prompt,buf,len,pos,cols);
 469             break;
 470         case 12: /* ctrl+l, clear screen */
 471             linenoiseClearScreen();
 472             refreshLine(fd,prompt,buf,len,pos,cols);
 473             break;
 474         case 23: /* ctrl+w, delete previous word */
 475             old_pos = pos;
 476             while (pos > 0 && buf[pos-1] == ' ')
 477                 pos--;
 478             while (pos > 0 && buf[pos-1] != ' ')
 479                 pos--;
 480             diff = old_pos - pos;
 481             memmove(&buf[pos], &buf[old_pos], len-old_pos+1);
 482             len -= diff;
 483             refreshLine(fd,prompt,buf,len,pos,cols);
 484             break;
 485         }
 486     }
 487     return len;
 488 }
 489
 490 static int linenoiseRaw(char *buf, size_t buflen, const char *prompt) {
 491     int fd = STDIN_FILENO;
 492     int count;
 493
 494     if (buflen == 0) {
 495         errno = EINVAL;
 496         return -1;
 497     }
 498     if (!isatty(STDIN_FILENO)) {
 499         if (fgets(buf, buflen, stdin) == NULL) return -1;
 500         count = strlen(buf);
 501         if (count && buf[count-1] == '\n') {
 502             count--;
 503             buf[count] = '\0';
 504         }
 505     } else {
 506         if (enableRawMode(fd) == -1) return -1;
 507         count = linenoisePrompt(fd, buf, buflen, prompt);
 508         disableRawMode(fd);
 509         printf("\n");
 510     }
 511     return count;
 512 }
 513
 514 char *linenoise(const char *prompt) {
 515     char buf[LINENOISE_MAX_LINE];
 516     int count;
 517
 518     if (isUnsupportedTerm()) {
 519         size_t len;
 520
 521         printf("%s",prompt);
 522         fflush(stdout);
 523         if (fgets(buf,LINENOISE_MAX_LINE,stdin) == NULL) return NULL;
 524         len = strlen(buf);
 525         while(len && (buf[len-1] == '\n' || buf[len-1] == '\r')) {
 526             len--;
 527             buf[len] = '\0';
 528         }
 529         return strdup(buf);
 530     } else {
 531         count = linenoiseRaw(buf,LINENOISE_MAX_LINE,prompt);
 532         if (count == -1) return NULL;
 533         return strdup(buf);
 534     }
 535 }
 536
 537 /* Register a callback function to be called for tab-completion. */
 538 void linenoiseSetCompletionCallback(linenoiseCompletionCallback *fn) {
 539     completionCallback = fn;
 540 }
 541
 542 void linenoiseAddCompletion(linenoiseCompletions *lc, char *str) {
 543     size_t len = strlen(str);
 544     char *copy = malloc(len+1);
 545     memcpy(copy,str,len+1);
 546     lc->cvec = realloc(lc->cvec,sizeof(char*)*(lc->len+1));
 547     lc->cvec[lc->len++] = copy;
 548 }
 549
 550 /* Using a circular buffer is smarter, but a bit more complex to handle. */
 551 int linenoiseHistoryAdd(const char *line) {
 552     char *linecopy;
 553
 554     if (history_max_len == 0) return 0;
 555     if (history == NULL) {
 556         history = malloc(sizeof(char*)*history_max_len);
 557         if (history == NULL) return 0;
 558         memset(history,0,(sizeof(char*)*history_max_len));
 559     }
 560     linecopy = strdup(line);
 561     if (!linecopy) return 0;
 562     if (history_len == history_max_len) {
 563         free(history[0]);
 564         memmove(history,history+1,sizeof(char*)*(history_max_len-1));
 565         history_len--;
 566     }
 567     history[history_len] = linecopy;
 568     history_len++;
 569     return 1;
 570 }
 571
 572 int linenoiseHistorySetMaxLen(int len) {
 573     char **new;
 574
 575     if (len < 1) return 0;
 576     if (history) {
 577         int tocopy = history_len;
 578
 579         new = malloc(sizeof(char*)*len);
 580         if (new == NULL) return 0;
 581         if (len < tocopy) tocopy = len;
 582         memcpy(new,history+(history_max_len-tocopy), sizeof(char*)*tocopy);
 583         free(history);
 584         history = new;
 585     }
 586     history_max_len = len;
 587     if (history_len > history_max_len)
 588         history_len = history_max_len;
 589     return 1;
 590 }
 591
 592 /* Save the history in the specified file. On success 0 is returned
 593  * otherwise -1 is returned. */
 594 int linenoiseHistorySave(char *filename) {
 595     FILE *fp = fopen(filename,"w");
 596     int j;
 597
 598     if (fp == NULL) return -1;
 599     for (j = 0; j < history_len; j++)
 600         fprintf(fp,"%s\n",history[j]);
 601     fclose(fp);
 602     return 0;
 603 }
 604
 605 /* Load the history from the specified file. If the file does not exist
 606  * zero is returned and no operation is performed.
 607  *
 608  * If the file exists and the operation succeeded 0 is returned, otherwise
 609  * on error -1 is returned. */
 610 int linenoiseHistoryLoad(char *filename) {
 611     FILE *fp = fopen(filename,"r");
 612     char buf[LINENOISE_MAX_LINE];
 613
 614     if (fp == NULL) return -1;
 615
 616     while (fgets(buf,LINENOISE_MAX_LINE,fp) != NULL) {
 617         char *p;
 618
 619         p = strchr(buf,'\r');
 620         if (!p) p = strchr(buf,'\n');
 621         if (p) *p = '\0';
 622         linenoiseHistoryAdd(buf);
 623     }
 624     fclose(fp);
 625     return 0;
 626 }