1 /*
2 * Copyright (C) 1984-2017 Mark Nudelman
3 *
4 * You may distribute under the terms of either the GNU General Public
5 * License or the Less License, as specified in the README file.
6 *
7 * For more information, see the README file.
8 */
9
10
11 /*
12 * Routines to decode user commands.
13 *
14 * This is all table driven.
15 * A command table is a sequence of command descriptors.
16 * Each command descriptor is a sequence of bytes with the following format:
17 * <c1><c2>...<cN><0><action>
18 * The characters c1,c2,...,cN are the command string; that is,
19 * the characters which the user must type.
20 * It is terminated by a null <0> byte.
21 * The byte after the null byte is the action code associated
22 * with the command string.
23 * If an action byte is OR-ed with A_EXTRA, this indicates
24 * that the option byte is followed by an extra string.
25 *
26 * There may be many command tables.
27 * The first (default) table is built-in.
28 * Other tables are read in from "lesskey" files.
29 * All the tables are linked together and are searched in order.
30 */
31
32 #include "less.h"
33 #include "cmd.h"
34 #include "lesskey.h"
35
36 extern int erase_char, erase2_char, kill_char;
37 extern int secure;
38
39 #define SK(k) \
40 SK_SPECIAL_KEY, (k), 6, 1, 1, 1
41 /*
42 * Command table is ordered roughly according to expected
43 * frequency of use, so the common commands are near the beginning.
44 */
45
46 static unsigned char cmdtable[] =
47 {
48 '\r',0, A_F_LINE,
49 '\n',0, A_F_LINE,
50 'e',0, A_F_LINE,
51 'j',0, A_F_LINE,
52 SK(SK_DOWN_ARROW),0, A_F_LINE,
53 CONTROL('E'),0, A_F_LINE,
54 CONTROL('N'),0, A_F_LINE,
55 'k',0, A_B_LINE,
56 'y',0, A_B_LINE,
57 CONTROL('Y'),0, A_B_LINE,
58 SK(SK_CONTROL_K),0, A_B_LINE,
59 CONTROL('P'),0, A_B_LINE,
60 SK(SK_UP_ARROW),0, A_B_LINE,
61 'J',0, A_FF_LINE,
62 'K',0, A_BF_LINE,
63 'Y',0, A_BF_LINE,
64 'd',0, A_F_SCROLL,
65 CONTROL('D'),0, A_F_SCROLL,
66 'u',0, A_B_SCROLL,
67 CONTROL('U'),0, A_B_SCROLL,
68 ' ',0, A_F_SCREEN,
69 'f',0, A_F_SCREEN,
70 CONTROL('F'),0, A_F_SCREEN,
71 CONTROL('V'),0, A_F_SCREEN,
72 SK(SK_PAGE_DOWN),0, A_F_SCREEN,
73 'b',0, A_B_SCREEN,
74 CONTROL('B'),0, A_B_SCREEN,
75 ESC,'v',0, A_B_SCREEN,
76 SK(SK_PAGE_UP),0, A_B_SCREEN,
77 'z',0, A_F_WINDOW,
78 'w',0, A_B_WINDOW,
79 ESC,' ',0, A_FF_SCREEN,
80 'F',0, A_F_FOREVER,
81 ESC,'F',0, A_F_UNTIL_HILITE,
82 'R',0, A_FREPAINT,
83 'r',0, A_REPAINT,
84 CONTROL('R'),0, A_REPAINT,
85 CONTROL('L'),0, A_REPAINT,
86 ESC,'u',0, A_UNDO_SEARCH,
87 'g',0, A_GOLINE,
88 SK(SK_HOME),0, A_GOLINE,
89 '<',0, A_GOLINE,
90 ESC,'<',0, A_GOLINE,
91 'p',0, A_PERCENT,
92 '%',0, A_PERCENT,
93 ESC,'[',0, A_LSHIFT,
94 ESC,']',0, A_RSHIFT,
95 ESC,'(',0, A_LSHIFT,
96 ESC,')',0, A_RSHIFT,
97 ESC,'{',0, A_LLSHIFT,
98 ESC,'}',0, A_RRSHIFT,
99 SK(SK_RIGHT_ARROW),0, A_RSHIFT,
100 SK(SK_LEFT_ARROW),0, A_LSHIFT,
101 SK(SK_CTL_RIGHT_ARROW),0, A_RRSHIFT,
102 SK(SK_CTL_LEFT_ARROW),0, A_LLSHIFT,
103 '{',0, A_F_BRACKET|A_EXTRA, '{','}',0,
104 '}',0, A_B_BRACKET|A_EXTRA, '{','}',0,
105 '(',0, A_F_BRACKET|A_EXTRA, '(',')',0,
106 ')',0, A_B_BRACKET|A_EXTRA, '(',')',0,
107 '[',0, A_F_BRACKET|A_EXTRA, '[',']',0,
108 ']',0, A_B_BRACKET|A_EXTRA, '[',']',0,
109 ESC,CONTROL('F'),0, A_F_BRACKET,
110 ESC,CONTROL('B'),0, A_B_BRACKET,
111 'G',0, A_GOEND,
112 ESC,'G',0, A_GOEND_BUF,
113 ESC,'>',0, A_GOEND,
114 '>',0, A_GOEND,
115 SK(SK_END),0, A_GOEND,
116 'P',0, A_GOPOS,
117
118 '0',0, A_DIGIT,
119 '1',0, A_DIGIT,
120 '2',0, A_DIGIT,
121 '3',0, A_DIGIT,
122 '4',0, A_DIGIT,
123 '5',0, A_DIGIT,
124 '6',0, A_DIGIT,
125 '7',0, A_DIGIT,
126 '8',0, A_DIGIT,
127 '9',0, A_DIGIT,
128 '.',0, A_DIGIT,
129
130 '=',0, A_STAT,
131 CONTROL('G'),0, A_STAT,
132 ':','f',0, A_STAT,
133 '/',0, A_F_SEARCH,
134 '?',0, A_B_SEARCH,
135 ESC,'/',0, A_F_SEARCH|A_EXTRA, '*',0,
136 ESC,'?',0, A_B_SEARCH|A_EXTRA, '*',0,
137 'n',0, A_AGAIN_SEARCH,
138 ESC,'n',0, A_T_AGAIN_SEARCH,
139 'N',0, A_REVERSE_SEARCH,
140 ESC,'N',0, A_T_REVERSE_SEARCH,
141 '&',0, A_FILTER,
142 'm',0, A_SETMARK,
143 'M',0, A_SETMARKBOT,
144 ESC,'m',0, A_CLRMARK,
145 '\'',0, A_GOMARK,
146 CONTROL('X'),CONTROL('X'),0, A_GOMARK,
147 'E',0, A_EXAMINE,
148 ':','e',0, A_EXAMINE,
149 CONTROL('X'),CONTROL('V'),0, A_EXAMINE,
150 ':','n',0, A_NEXT_FILE,
151 ':','p',0, A_PREV_FILE,
152 't',0, A_NEXT_TAG,
153 'T',0, A_PREV_TAG,
154 ':','x',0, A_INDEX_FILE,
155 ':','d',0, A_REMOVE_FILE,
156 '-',0, A_OPT_TOGGLE,
157 ':','t',0, A_OPT_TOGGLE|A_EXTRA, 't',0,
158 's',0, A_OPT_TOGGLE|A_EXTRA, 'o',0,
159 '_',0, A_DISP_OPTION,
160 '|',0, A_PIPE,
161 'v',0, A_VISUAL,
162 '!',0, A_SHELL,
163 '+',0, A_FIRSTCMD,
164
165 'H',0, A_HELP,
166 'h',0, A_HELP,
167 SK(SK_F1),0, A_HELP,
168 'V',0, A_VERSION,
169 'q',0, A_QUIT,
170 'Q',0, A_QUIT,
171 ':','q',0, A_QUIT,
172 ':','Q',0, A_QUIT,
173 'Z','Z',0, A_QUIT
174 };
175
176 static unsigned char edittable[] =
177 {
178 '\t',0, EC_F_COMPLETE, /* TAB */
179 '\17',0, EC_B_COMPLETE, /* BACKTAB */
180 SK(SK_BACKTAB),0, EC_B_COMPLETE, /* BACKTAB */
181 ESC,'\t',0, EC_B_COMPLETE, /* ESC TAB */
182 CONTROL('L'),0, EC_EXPAND, /* CTRL-L */
183 CONTROL('V'),0, EC_LITERAL, /* BACKSLASH */
184 CONTROL('A'),0, EC_LITERAL, /* BACKSLASH */
185 ESC,'l',0, EC_RIGHT, /* ESC l */
186 SK(SK_RIGHT_ARROW),0, EC_RIGHT, /* RIGHTARROW */
187 ESC,'h',0, EC_LEFT, /* ESC h */
188 SK(SK_LEFT_ARROW),0, EC_LEFT, /* LEFTARROW */
189 ESC,'b',0, EC_W_LEFT, /* ESC b */
190 ESC,SK(SK_LEFT_ARROW),0, EC_W_LEFT, /* ESC LEFTARROW */
191 SK(SK_CTL_LEFT_ARROW),0, EC_W_LEFT, /* CTRL-LEFTARROW */
192 ESC,'w',0, EC_W_RIGHT, /* ESC w */
193 ESC,SK(SK_RIGHT_ARROW),0, EC_W_RIGHT, /* ESC RIGHTARROW */
194 SK(SK_CTL_RIGHT_ARROW),0, EC_W_RIGHT, /* CTRL-RIGHTARROW */
195 ESC,'i',0, EC_INSERT, /* ESC i */
196 SK(SK_INSERT),0, EC_INSERT, /* INSERT */
197 ESC,'x',0, EC_DELETE, /* ESC x */
198 SK(SK_DELETE),0, EC_DELETE, /* DELETE */
199 ESC,'X',0, EC_W_DELETE, /* ESC X */
200 ESC,SK(SK_DELETE),0, EC_W_DELETE, /* ESC DELETE */
201 SK(SK_CTL_DELETE),0, EC_W_DELETE, /* CTRL-DELETE */
202 SK(SK_CTL_BACKSPACE),0, EC_W_BACKSPACE, /* CTRL-BACKSPACE */
203 ESC,'\b',0, EC_W_BACKSPACE, /* ESC BACKSPACE */
204 ESC,'0',0, EC_HOME, /* ESC 0 */
205 SK(SK_HOME),0, EC_HOME, /* HOME */
206 ESC,'$',0, EC_END, /* ESC $ */
207 SK(SK_END),0, EC_END, /* END */
208 ESC,'k',0, EC_UP, /* ESC k */
209 SK(SK_UP_ARROW),0, EC_UP, /* UPARROW */
210 ESC,'j',0, EC_DOWN, /* ESC j */
211 SK(SK_DOWN_ARROW),0, EC_DOWN, /* DOWNARROW */
212 CONTROL('G'),0, EC_ABORT, /* CTRL-G */
213 };
214
215 /*
216 * Structure to support a list of command tables.
217 */
218 struct tablelist
219 {
220 struct tablelist *t_next;
221 char *t_start;
222 char *t_end;
223 };
224
225 /*
226 * List of command tables and list of line-edit tables.
227 */
228 static struct tablelist *list_fcmd_tables = NULL;
229 static struct tablelist *list_ecmd_tables = NULL;
230 static struct tablelist *list_var_tables = NULL;
231 static struct tablelist *list_sysvar_tables = NULL;
232
233
234 /*
235 * Expand special key abbreviations in a command table.
236 */
237 static void
expand_special_keys(table,len)238 expand_special_keys(table, len)
239 char *table;
240 int len;
241 {
242 char *fm;
243 char *to;
244 int a;
245 char *repl;
246 int klen;
247
248 for (fm = table; fm < table + len; )
249 {
250 /*
251 * Rewrite each command in the table with any
252 * special key abbreviations expanded.
253 */
254 for (to = fm; *fm != '\0'; )
255 {
256 if (*fm != SK_SPECIAL_KEY)
257 {
258 *to++ = *fm++;
259 continue;
260 }
261 /*
262 * After SK_SPECIAL_KEY, next byte is the type
263 * of special key (one of the SK_* contants),
264 * and the byte after that is the number of bytes,
265 * N, reserved by the abbreviation (including the
266 * SK_SPECIAL_KEY and key type bytes).
267 * Replace all N bytes with the actual bytes
268 * output by the special key on this terminal.
269 */
270 repl = special_key_str(fm[1]);
271 klen = fm[2] & 0377;
272 fm += klen;
273 if (repl == NULL || (int) strlen(repl) > klen)
274 repl = "\377";
275 while (*repl != '\0')
276 *to++ = *repl++;
277 }
278 *to++ = '\0';
279 /*
280 * Fill any unused bytes between end of command and
281 * the action byte with A_SKIP.
282 */
283 while (to <= fm)
284 *to++ = A_SKIP;
285 fm++;
286 a = *fm++ & 0377;
287 if (a & A_EXTRA)
288 {
289 while (*fm++ != '\0')
290 continue;
291 }
292 }
293 }
294
295 /*
296 * Expand special key abbreviations in a list of command tables.
297 */
298 static void
expand_cmd_table(tlist)299 expand_cmd_table(tlist)
300 struct tablelist *tlist;
301 {
302 struct tablelist *t;
303 for (t = tlist; t != NULL; t = t->t_next)
304 {
305 expand_special_keys(t->t_start, t->t_end - t->t_start);
306 }
307 }
308
309 /*
310 * Expand special key abbreviations in all command tables.
311 */
312 public void
expand_cmd_tables()313 expand_cmd_tables()
314 {
315 expand_cmd_table(list_fcmd_tables);
316 expand_cmd_table(list_ecmd_tables);
317 expand_cmd_table(list_var_tables);
318 expand_cmd_table(list_sysvar_tables);
319 }
320
321
322 /*
323 * Initialize the command lists.
324 */
325 public void
init_cmds()326 init_cmds()
327 {
328 /*
329 * Add the default command tables.
330 */
331 add_fcmd_table((char*)cmdtable, sizeof(cmdtable));
332 add_ecmd_table((char*)edittable, sizeof(edittable));
333 #if USERFILE
334 /*
335 * For backwards compatibility,
336 * try to add tables in the OLD system lesskey file.
337 */
338 #ifdef BINDIR
339 add_hometable(NULL, BINDIR "/.sysless", 1);
340 #endif
341 /*
342 * Try to add the tables in the system lesskey file.
343 */
344 add_hometable("LESSKEY_SYSTEM", LESSKEYFILE_SYS, 1);
345 /*
346 * Try to add the tables in the standard lesskey file "$HOME/.less".
347 */
348 add_hometable("LESSKEY", LESSKEYFILE, 0);
349 #endif
350 }
351
352 /*
353 * Add a command table.
354 */
355 static int
add_cmd_table(tlist,buf,len)356 add_cmd_table(tlist, buf, len)
357 struct tablelist **tlist;
358 char *buf;
359 int len;
360 {
361 struct tablelist *t;
362
363 if (len == 0)
364 return (0);
365 /*
366 * Allocate a tablelist structure, initialize it,
367 * and link it into the list of tables.
368 */
369 if ((t = (struct tablelist *)
370 calloc(1, sizeof(struct tablelist))) == NULL)
371 {
372 return (-1);
373 }
374 t->t_start = buf;
375 t->t_end = buf + len;
376 t->t_next = *tlist;
377 *tlist = t;
378 return (0);
379 }
380
381 /*
382 * Add a command table.
383 */
384 public void
add_fcmd_table(buf,len)385 add_fcmd_table(buf, len)
386 char *buf;
387 int len;
388 {
389 if (add_cmd_table(&list_fcmd_tables, buf, len) < 0)
390 error("Warning: some commands disabled", NULL_PARG);
391 }
392
393 /*
394 * Add an editing command table.
395 */
396 public void
add_ecmd_table(buf,len)397 add_ecmd_table(buf, len)
398 char *buf;
399 int len;
400 {
401 if (add_cmd_table(&list_ecmd_tables, buf, len) < 0)
402 error("Warning: some edit commands disabled", NULL_PARG);
403 }
404
405 /*
406 * Add an environment variable table.
407 */
408 static void
add_var_table(tlist,buf,len)409 add_var_table(tlist, buf, len)
410 struct tablelist **tlist;
411 char *buf;
412 int len;
413 {
414 if (add_cmd_table(tlist, buf, len) < 0)
415 error("Warning: environment variables from lesskey file unavailable", NULL_PARG);
416 }
417
418 /*
419 * Search a single command table for the command string in cmd.
420 */
421 static int
cmd_search(cmd,table,endtable,sp)422 cmd_search(cmd, table, endtable, sp)
423 char *cmd;
424 char *table;
425 char *endtable;
426 char **sp;
427 {
428 char *p;
429 char *q;
430 int a;
431
432 *sp = NULL;
433 for (p = table, q = cmd; p < endtable; p++, q++)
434 {
435 if (*p == *q)
436 {
437 /*
438 * Current characters match.
439 * If we're at the end of the string, we've found it.
440 * Return the action code, which is the character
441 * after the null at the end of the string
442 * in the command table.
443 */
444 if (*p == '\0')
445 {
446 a = *++p & 0377;
447 while (a == A_SKIP)
448 a = *++p & 0377;
449 if (a == A_END_LIST)
450 {
451 /*
452 * We get here only if the original
453 * cmd string passed in was empty ("").
454 * I don't think that can happen,
455 * but just in case ...
456 */
457 return (A_UINVALID);
458 }
459 /*
460 * Check for an "extra" string.
461 */
462 if (a & A_EXTRA)
463 {
464 *sp = ++p;
465 a &= ~A_EXTRA;
466 }
467 return (a);
468 }
469 } else if (*q == '\0')
470 {
471 /*
472 * Hit the end of the user's command,
473 * but not the end of the string in the command table.
474 * The user's command is incomplete.
475 */
476 return (A_PREFIX);
477 } else
478 {
479 /*
480 * Not a match.
481 * Skip ahead to the next command in the
482 * command table, and reset the pointer
483 * to the beginning of the user's command.
484 */
485 if (*p == '\0' && p[1] == A_END_LIST)
486 {
487 /*
488 * A_END_LIST is a special marker that tells
489 * us to abort the cmd search.
490 */
491 return (A_UINVALID);
492 }
493 while (*p++ != '\0')
494 continue;
495 while (*p == A_SKIP)
496 p++;
497 if (*p & A_EXTRA)
498 while (*++p != '\0')
499 continue;
500 q = cmd-1;
501 }
502 }
503 /*
504 * No match found in the entire command table.
505 */
506 return (A_INVALID);
507 }
508
509 /*
510 * Decode a command character and return the associated action.
511 * The "extra" string, if any, is returned in sp.
512 */
513 static int
cmd_decode(tlist,cmd,sp)514 cmd_decode(tlist, cmd, sp)
515 struct tablelist *tlist;
516 char *cmd;
517 char **sp;
518 {
519 struct tablelist *t;
520 int action = A_INVALID;
521
522 /*
523 * Search thru all the command tables.
524 * Stop when we find an action which is not A_INVALID.
525 */
526 for (t = tlist; t != NULL; t = t->t_next)
527 {
528 action = cmd_search(cmd, t->t_start, t->t_end, sp);
529 if (action != A_INVALID)
530 break;
531 }
532 if (action == A_UINVALID)
533 action = A_INVALID;
534 return (action);
535 }
536
537 /*
538 * Decode a command from the cmdtables list.
539 */
540 public int
fcmd_decode(cmd,sp)541 fcmd_decode(cmd, sp)
542 char *cmd;
543 char **sp;
544 {
545 return (cmd_decode(list_fcmd_tables, cmd, sp));
546 }
547
548 /*
549 * Decode a command from the edittables list.
550 */
551 public int
ecmd_decode(cmd,sp)552 ecmd_decode(cmd, sp)
553 char *cmd;
554 char **sp;
555 {
556 return (cmd_decode(list_ecmd_tables, cmd, sp));
557 }
558
559 /*
560 * Get the value of an environment variable.
561 * Looks first in the lesskey file, then in the real environment.
562 */
563 public char *
lgetenv(var)564 lgetenv(var)
565 char *var;
566 {
567 int a;
568 char *s;
569
570 a = cmd_decode(list_var_tables, var, &s);
571 if (a == EV_OK)
572 return (s);
573 s = getenv(var);
574 if (s != NULL && *s != '\0')
575 return (s);
576 a = cmd_decode(list_sysvar_tables, var, &s);
577 if (a == EV_OK)
578 return (s);
579 return (NULL);
580 }
581
582 #if USERFILE
583 /*
584 * Get an "integer" from a lesskey file.
585 * Integers are stored in a funny format:
586 * two bytes, low order first, in radix KRADIX.
587 */
588 static int
gint(sp)589 gint(sp)
590 char **sp;
591 {
592 int n;
593
594 n = *(*sp)++;
595 n += *(*sp)++ * KRADIX;
596 return (n);
597 }
598
599 /*
600 * Process an old (pre-v241) lesskey file.
601 */
602 static int
old_lesskey(buf,len)603 old_lesskey(buf, len)
604 char *buf;
605 int len;
606 {
607 /*
608 * Old-style lesskey file.
609 * The file must end with either
610 * ...,cmd,0,action
611 * or ...,cmd,0,action|A_EXTRA,string,0
612 * So the last byte or the second to last byte must be zero.
613 */
614 if (buf[len-1] != '\0' && buf[len-2] != '\0')
615 return (-1);
616 add_fcmd_table(buf, len);
617 return (0);
618 }
619
620 /*
621 * Process a new (post-v241) lesskey file.
622 */
623 static int
new_lesskey(buf,len,sysvar)624 new_lesskey(buf, len, sysvar)
625 char *buf;
626 int len;
627 int sysvar;
628 {
629 char *p;
630 int c;
631 int n;
632
633 /*
634 * New-style lesskey file.
635 * Extract the pieces.
636 */
637 if (buf[len-3] != C0_END_LESSKEY_MAGIC ||
638 buf[len-2] != C1_END_LESSKEY_MAGIC ||
639 buf[len-1] != C2_END_LESSKEY_MAGIC)
640 return (-1);
641 p = buf + 4;
642 for (;;)
643 {
644 c = *p++;
645 switch (c)
646 {
647 case CMD_SECTION:
648 n = gint(&p);
649 add_fcmd_table(p, n);
650 p += n;
651 break;
652 case EDIT_SECTION:
653 n = gint(&p);
654 add_ecmd_table(p, n);
655 p += n;
656 break;
657 case VAR_SECTION:
658 n = gint(&p);
659 add_var_table((sysvar) ?
660 &list_sysvar_tables : &list_var_tables, p, n);
661 p += n;
662 break;
663 case END_SECTION:
664 return (0);
665 default:
666 /*
667 * Unrecognized section type.
668 */
669 return (-1);
670 }
671 }
672 }
673
674 /*
675 * Set up a user command table, based on a "lesskey" file.
676 */
677 public int
lesskey(filename,sysvar)678 lesskey(filename, sysvar)
679 char *filename;
680 int sysvar;
681 {
682 char *buf;
683 POSITION len;
684 long n;
685 int f;
686
687 if (secure)
688 return (1);
689 /*
690 * Try to open the lesskey file.
691 */
692 f = open(filename, OPEN_READ);
693 if (f < 0)
694 return (1);
695
696 /*
697 * Read the file into a buffer.
698 * We first figure out the size of the file and allocate space for it.
699 * {{ Minimal error checking is done here.
700 * A garbage .less file will produce strange results.
701 * To avoid a large amount of error checking code here, we
702 * rely on the lesskey program to generate a good .less file. }}
703 */
704 len = filesize(f);
705 if (len == NULL_POSITION || len < 3)
706 {
707 /*
708 * Bad file (valid file must have at least 3 chars).
709 */
710 close(f);
711 return (-1);
712 }
713 if ((buf = (char *) calloc((int)len, sizeof(char))) == NULL)
714 {
715 close(f);
716 return (-1);
717 }
718 if (lseek(f, (off_t)0, SEEK_SET) == BAD_LSEEK)
719 {
720 free(buf);
721 close(f);
722 return (-1);
723 }
724 n = read(f, buf, (unsigned int) len);
725 close(f);
726 if (n != len)
727 {
728 free(buf);
729 return (-1);
730 }
731
732 /*
733 * Figure out if this is an old-style (before version 241)
734 * or new-style lesskey file format.
735 */
736 if (buf[0] != C0_LESSKEY_MAGIC || buf[1] != C1_LESSKEY_MAGIC ||
737 buf[2] != C2_LESSKEY_MAGIC || buf[3] != C3_LESSKEY_MAGIC)
738 return (old_lesskey(buf, (int)len));
739 return (new_lesskey(buf, (int)len, sysvar));
740 }
741
742 /*
743 * Add the standard lesskey file "$HOME/.less"
744 */
745 public void
add_hometable(envname,def_filename,sysvar)746 add_hometable(envname, def_filename, sysvar)
747 char *envname;
748 char *def_filename;
749 int sysvar;
750 {
751 char *filename;
752 PARG parg;
753
754 if (envname != NULL && (filename = lgetenv(envname)) != NULL)
755 filename = save(filename);
756 else if (sysvar)
757 filename = save(def_filename);
758 else
759 filename = homefile(def_filename);
760 if (filename == NULL)
761 return;
762 if (lesskey(filename, sysvar) < 0)
763 {
764 parg.p_string = filename;
765 error("Cannot use lesskey file \"%s\"", &parg);
766 }
767 free(filename);
768 }
769 #endif
770
771 /*
772 * See if a char is a special line-editing command.
773 */
774 public int
editchar(c,flags)775 editchar(c, flags)
776 int c;
777 int flags;
778 {
779 int action;
780 int nch;
781 char *s;
782 char usercmd[MAX_CMDLEN+1];
783
784 /*
785 * An editing character could actually be a sequence of characters;
786 * for example, an escape sequence sent by pressing the uparrow key.
787 * To match the editing string, we use the command decoder
788 * but give it the edit-commands command table
789 * This table is constructed to match the user's keyboard.
790 */
791 if (c == erase_char || c == erase2_char)
792 return (EC_BACKSPACE);
793 if (c == kill_char)
794 return (EC_LINEKILL);
795
796 /*
797 * Collect characters in a buffer.
798 * Start with the one we have, and get more if we need them.
799 */
800 nch = 0;
801 do {
802 if (nch > 0)
803 c = getcc();
804 usercmd[nch] = c;
805 usercmd[nch+1] = '\0';
806 nch++;
807 action = ecmd_decode(usercmd, &s);
808 } while (action == A_PREFIX);
809
810 if (flags & EC_NORIGHTLEFT)
811 {
812 switch (action)
813 {
814 case EC_RIGHT:
815 case EC_LEFT:
816 action = A_INVALID;
817 break;
818 }
819 }
820 #if CMD_HISTORY
821 if (flags & EC_NOHISTORY)
822 {
823 /*
824 * The caller says there is no history list.
825 * Reject any history-manipulation action.
826 */
827 switch (action)
828 {
829 case EC_UP:
830 case EC_DOWN:
831 action = A_INVALID;
832 break;
833 }
834 }
835 #endif
836 #if TAB_COMPLETE_FILENAME
837 if (flags & EC_NOCOMPLETE)
838 {
839 /*
840 * The caller says we don't want any filename completion cmds.
841 * Reject them.
842 */
843 switch (action)
844 {
845 case EC_F_COMPLETE:
846 case EC_B_COMPLETE:
847 case EC_EXPAND:
848 action = A_INVALID;
849 break;
850 }
851 }
852 #endif
853 if ((flags & EC_PEEK) || action == A_INVALID)
854 {
855 /*
856 * We're just peeking, or we didn't understand the command.
857 * Unget all the characters we read in the loop above.
858 * This does NOT include the original character that was
859 * passed in as a parameter.
860 */
861 while (nch > 1)
862 {
863 ungetcc(usercmd[--nch]);
864 }
865 } else
866 {
867 if (s != NULL)
868 ungetsc(s);
869 }
870 return action;
871 }
872
873