1/*
2 * Copyright (C) 1984-2007 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 about less, or for information on how to
8 * contact the author, see the README file.
9 */
10
11
12/*
13 * Routines to decode user commands.
14 *
15 * This is all table driven.
16 * A command table is a sequence of command descriptors.
17 * Each command descriptor is a sequence of bytes with the following format:
18 * <c1><c2>...<cN><0><action>
19 * The characters c1,c2,...,cN are the command string; that is,
20 * the characters which the user must type.
21 * It is terminated by a null <0> byte.
22 * The byte after the null byte is the action code associated
23 * with the command string.
24 * If an action byte is OR-ed with A_EXTRA, this indicates
25 * that the option byte is followed by an extra string.
26 *
27 * There may be many command tables.
28 * The first (default) table is built-in.
29 * Other tables are read in from "lesskey" files.
30 * All the tables are linked together and are searched in order.
31 */
32
33#include "less.h"
34#include "cmd.h"
35#include "lesskey.h"
36
37extern int erase_char, erase2_char, kill_char;
38extern int secure;
39
40#define SK(k) \
41 SK_SPECIAL_KEY, (k), 6, 1, 1, 1
42/*
43 * Command table is ordered roughly according to expected
44 * frequency of use, so the common commands are near the beginning.
45 */
46
47static unsigned char cmdtable[] =
48{
49 '\r',0, A_F_LINE,
50 '\n',0, A_F_LINE,
51 'e',0, A_F_LINE,
52 'j',0, A_F_LINE,
53 SK(SK_DOWN_ARROW),0, A_F_LINE,
54 CONTROL('E'),0, A_F_LINE,
55 CONTROL('N'),0, A_F_LINE,
56 'k',0, A_B_LINE,
57 'y',0, A_B_LINE,
58 CONTROL('Y'),0, A_B_LINE,
59 SK(SK_CONTROL_K),0, A_B_LINE,
60 CONTROL('P'),0, A_B_LINE,
61 SK(SK_UP_ARROW),0, A_B_LINE,
62 'J',0, A_FF_LINE,
63 'K',0, A_BF_LINE,
64 'Y',0, A_BF_LINE,
65 'd',0, A_F_SCROLL,
66 CONTROL('D'),0, A_F_SCROLL,
67 'u',0, A_B_SCROLL,
68 CONTROL('U'),0, A_B_SCROLL,
69 ' ',0, A_F_SCREEN,
70 'f',0, A_F_SCREEN,
71 CONTROL('F'),0, A_F_SCREEN,
72 CONTROL('V'),0, A_F_SCREEN,
73 SK(SK_PAGE_DOWN),0, A_F_SCREEN,
74 'b',0, A_B_SCREEN,
75 CONTROL('B'),0, A_B_SCREEN,
76 ESC,'v',0, A_B_SCREEN,
77 SK(SK_PAGE_UP),0, A_B_SCREEN,
78 'z',0, A_F_WINDOW,
79 'w',0, A_B_WINDOW,
80 ESC,' ',0, A_FF_SCREEN,
81 'F',0, A_F_FOREVER,
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 SK(SK_RIGHT_ARROW),0, A_RSHIFT,
98 SK(SK_LEFT_ARROW),0, A_LSHIFT,
99 '{',0, A_F_BRACKET|A_EXTRA, '{','}',0,
100 '}',0, A_B_BRACKET|A_EXTRA, '{','}',0,
101 '(',0, A_F_BRACKET|A_EXTRA, '(',')',0,
102 ')',0, A_B_BRACKET|A_EXTRA, '(',')',0,
103 '[',0, A_F_BRACKET|A_EXTRA, '[',']',0,
104 ']',0, A_B_BRACKET|A_EXTRA, '[',']',0,
105 ESC,CONTROL('F'),0, A_F_BRACKET,
106 ESC,CONTROL('B'),0, A_B_BRACKET,
107 'G',0, A_GOEND,
108 ESC,'>',0, A_GOEND,
109 '>',0, A_GOEND,
110 SK(SK_END),0, A_GOEND,
111 'P',0, A_GOPOS,
112
113 '0',0, A_DIGIT,
114 '1',0, A_DIGIT,
115 '2',0, A_DIGIT,
116 '3',0, A_DIGIT,
117 '4',0, A_DIGIT,
118 '5',0, A_DIGIT,
119 '6',0, A_DIGIT,
120 '7',0, A_DIGIT,
121 '8',0, A_DIGIT,
122 '9',0, A_DIGIT,
123 '.',0, A_DIGIT,
124
125 '=',0, A_STAT,
126 CONTROL('G'),0, A_STAT,
127 ':','f',0, A_STAT,
128 '/',0, A_F_SEARCH,
129 '?',0, A_B_SEARCH,
130 ESC,'/',0, A_F_SEARCH|A_EXTRA, '*',0,
131 ESC,'?',0, A_B_SEARCH|A_EXTRA, '*',0,
132 'n',0, A_AGAIN_SEARCH,
133 ESC,'n',0, A_T_AGAIN_SEARCH,
134 'N',0, A_REVERSE_SEARCH,
135 ESC,'N',0, A_T_REVERSE_SEARCH,
136 'm',0, A_SETMARK,
137 '\'',0, A_GOMARK,
138 CONTROL('X'),CONTROL('X'),0, A_GOMARK,
139 'E',0, A_EXAMINE,
140 ':','e',0, A_EXAMINE,
141 CONTROL('X'),CONTROL('V'),0, A_EXAMINE,
142 ':','n',0, A_NEXT_FILE,
143 ':','p',0, A_PREV_FILE,
144 't',0, A_NEXT_TAG,
145 'T',0, A_PREV_TAG,
146 ':','x',0, A_INDEX_FILE,
147 ':','d',0, A_REMOVE_FILE,
148 '-',0, A_OPT_TOGGLE,
149 ':','t',0, A_OPT_TOGGLE|A_EXTRA, 't',0,
150 's',0, A_OPT_TOGGLE|A_EXTRA, 'o',0,
151 '_',0, A_DISP_OPTION,
152 '|',0, A_PIPE,
153 'v',0, A_VISUAL,
154 '!',0, A_SHELL,
155 '+',0, A_FIRSTCMD,
156
157 'H',0, A_HELP,
158 'h',0, A_HELP,
159 SK(SK_F1),0, A_HELP,
160 'V',0, A_VERSION,
161 'q',0, A_QUIT,
162 'Q',0, A_QUIT,
163 ':','q',0, A_QUIT,
164 ':','Q',0, A_QUIT,
165 'Z','Z',0, A_QUIT
166};
167
168static unsigned char edittable[] =
169{
170 '\t',0, EC_F_COMPLETE, /* TAB */
171 '\17',0, EC_B_COMPLETE, /* BACKTAB */
172 SK(SK_BACKTAB),0, EC_B_COMPLETE, /* BACKTAB */
173 ESC,'\t',0, EC_B_COMPLETE, /* ESC TAB */
174 CONTROL('L'),0, EC_EXPAND, /* CTRL-L */
175 CONTROL('V'),0, EC_LITERAL, /* BACKSLASH */
176 CONTROL('A'),0, EC_LITERAL, /* BACKSLASH */
177 ESC,'l',0, EC_RIGHT, /* ESC l */
178 SK(SK_RIGHT_ARROW),0, EC_RIGHT, /* RIGHTARROW */
179 ESC,'h',0, EC_LEFT, /* ESC h */
180 SK(SK_LEFT_ARROW),0, EC_LEFT, /* LEFTARROW */
181 ESC,'b',0, EC_W_LEFT, /* ESC b */
182 ESC,SK(SK_LEFT_ARROW),0, EC_W_LEFT, /* ESC LEFTARROW */
183 SK(SK_CTL_LEFT_ARROW),0, EC_W_LEFT, /* CTRL-LEFTARROW */
184 ESC,'w',0, EC_W_RIGHT, /* ESC w */
185 ESC,SK(SK_RIGHT_ARROW),0, EC_W_RIGHT, /* ESC RIGHTARROW */
186 SK(SK_CTL_RIGHT_ARROW),0, EC_W_RIGHT, /* CTRL-RIGHTARROW */
187 ESC,'i',0, EC_INSERT, /* ESC i */
188 SK(SK_INSERT),0, EC_INSERT, /* INSERT */
189 ESC,'x',0, EC_DELETE, /* ESC x */
190 SK(SK_DELETE),0, EC_DELETE, /* DELETE */
191 ESC,'X',0, EC_W_DELETE, /* ESC X */
192 ESC,SK(SK_DELETE),0, EC_W_DELETE, /* ESC DELETE */
193 SK(SK_CTL_DELETE),0, EC_W_DELETE, /* CTRL-DELETE */
194 SK(SK_CTL_BACKSPACE),0, EC_W_BACKSPACE, /* CTRL-BACKSPACE */
195 ESC,'\b',0, EC_W_BACKSPACE, /* ESC BACKSPACE */
196 ESC,'0',0, EC_HOME, /* ESC 0 */
197 SK(SK_HOME),0, EC_HOME, /* HOME */
198 ESC,'$',0, EC_END, /* ESC $ */
199 SK(SK_END),0, EC_END, /* END */
200 ESC,'k',0, EC_UP, /* ESC k */
201 SK(SK_UP_ARROW),0, EC_UP, /* UPARROW */
202 ESC,'j',0, EC_DOWN, /* ESC j */
203 SK(SK_DOWN_ARROW),0, EC_DOWN, /* DOWNARROW */
204};
205
206/*
207 * Structure to support a list of command tables.
208 */
209struct tablelist
210{
211 struct tablelist *t_next;
212 char *t_start;
213 char *t_end;
214};
215
216/*
217 * List of command tables and list of line-edit tables.
218 */
219static struct tablelist *list_fcmd_tables = NULL;
220static struct tablelist *list_ecmd_tables = NULL;
221static struct tablelist *list_var_tables = NULL;
222static struct tablelist *list_sysvar_tables = NULL;
223
224
225/*
226 * Expand special key abbreviations in a command table.
227 */
228 static void
229expand_special_keys(table, len)
230 char *table;
231 int len;
232{
233 register char *fm;
234 register char *to;
235 register int a;
236 char *repl;
237 int klen;
238
239 for (fm = table; fm < table + len; )
240 {
241 /*
242 * Rewrite each command in the table with any
243 * special key abbreviations expanded.
244 */
245 for (to = fm; *fm != '\0'; )
246 {
247 if (*fm != SK_SPECIAL_KEY)
248 {
249 *to++ = *fm++;
250 continue;
251 }
252 /*
253 * After SK_SPECIAL_KEY, next byte is the type
254 * of special key (one of the SK_* contants),
255 * and the byte after that is the number of bytes,
256 * N, reserved by the abbreviation (including the
257 * SK_SPECIAL_KEY and key type bytes).
258 * Replace all N bytes with the actual bytes
259 * output by the special key on this terminal.
260 */
261 repl = special_key_str(fm[1]);
262 klen = fm[2] & 0377;
263 fm += klen;
264 if (repl == NULL || (int) strlen(repl) > klen)
265 repl = "\377";
266 while (*repl != '\0')
267 *to++ = *repl++;
268 }
269 *to++ = '\0';
270 /*
271 * Fill any unused bytes between end of command and
272 * the action byte with A_SKIP.
273 */
274 while (to <= fm)
275 *to++ = A_SKIP;
276 fm++;
277 a = *fm++ & 0377;
278 if (a & A_EXTRA)
279 {
280 while (*fm++ != '\0')
281 continue;
282 }
283 }
284}
285
286/*
287 * Initialize the command lists.
288 */
289 public void
290init_cmds()
291{
292 /*
293 * Add the default command tables.
294 */
295 add_fcmd_table((char*)cmdtable, sizeof(cmdtable));
296 add_ecmd_table((char*)edittable, sizeof(edittable));
297#if USERFILE
298 /*
299 * For backwards compatibility,
300 * try to add tables in the OLD system lesskey file.
301 */
302#ifdef BINDIR
303 add_hometable(NULL, BINDIR "/.sysless", 1);
304#endif
305 /*
306 * Try to add the tables in the system lesskey file.
307 */
308 add_hometable("LESSKEY_SYSTEM", LESSKEYFILE_SYS, 1);
309 /*
310 * Try to add the tables in the standard lesskey file "$HOME/.less".
311 */
312 add_hometable("LESSKEY", LESSKEYFILE, 0);
313#endif
314}
315
316/*
317 * Add a command table.
318 */
319 static int
320add_cmd_table(tlist, buf, len)
321 struct tablelist **tlist;
322 char *buf;
323 int len;
324{
325 register struct tablelist *t;
326
327 if (len == 0)
328 return (0);
329 /*
330 * Allocate a tablelist structure, initialize it,
331 * and link it into the list of tables.
332 */
333 if ((t = (struct tablelist *)
334 calloc(1, sizeof(struct tablelist))) == NULL)
335 {
336 return (-1);
337 }
338 expand_special_keys(buf, len);
339 t->t_start = buf;
340 t->t_end = buf + len;
341 t->t_next = *tlist;
342 *tlist = t;
343 return (0);
344}
345
346/*
347 * Add a command table.
348 */
349 public void
350add_fcmd_table(buf, len)
351 char *buf;
352 int len;
353{
354 if (add_cmd_table(&list_fcmd_tables, buf, len) < 0)
355 error("Warning: some commands disabled", NULL_PARG);
356}
357
358/*
359 * Add an editing command table.
360 */
361 public void
362add_ecmd_table(buf, len)
363 char *buf;
364 int len;
365{
366 if (add_cmd_table(&list_ecmd_tables, buf, len) < 0)
367 error("Warning: some edit commands disabled", NULL_PARG);
368}
369
370/*
371 * Add an environment variable table.
372 */
373 static void
374add_var_table(tlist, buf, len)
375 struct tablelist **tlist;
376 char *buf;
377 int len;
378{
379 if (add_cmd_table(tlist, buf, len) < 0)
380 error("Warning: environment variables from lesskey file unavailable", NULL_PARG);
381}
382
383/*
384 * Search a single command table for the command string in cmd.
385 */
386 static int
387cmd_search(cmd, table, endtable, sp)
388 char *cmd;
389 char *table;
390 char *endtable;
391 char **sp;
392{
393 register char *p;
394 register char *q;
395 register int a;
396
397 *sp = NULL;
398 for (p = table, q = cmd; p < endtable; p++, q++)
399 {
400 if (*p == *q)
401 {
402 /*
403 * Current characters match.
404 * If we're at the end of the string, we've found it.
405 * Return the action code, which is the character
406 * after the null at the end of the string
407 * in the command table.
408 */
409 if (*p == '\0')
410 {
411 a = *++p & 0377;
412 while (a == A_SKIP)
413 a = *++p & 0377;
414 if (a == A_END_LIST)
415 {
416 /*
417 * We get here only if the original
418 * cmd string passed in was empty ("").
419 * I don't think that can happen,
420 * but just in case ...
421 */
422 return (A_UINVALID);
423 }
424 /*
425 * Check for an "extra" string.
426 */
427 if (a & A_EXTRA)
428 {
429 *sp = ++p;
430 a &= ~A_EXTRA;
431 }
432 return (a);
433 }
434 } else if (*q == '\0')
435 {
436 /*
437 * Hit the end of the user's command,
438 * but not the end of the string in the command table.
439 * The user's command is incomplete.
440 */
441 return (A_PREFIX);
442 } else
443 {
444 /*
445 * Not a match.
446 * Skip ahead to the next command in the
447 * command table, and reset the pointer
448 * to the beginning of the user's command.
449 */
450 if (*p == '\0' && p[1] == A_END_LIST)
451 {
452 /*
453 * A_END_LIST is a special marker that tells
454 * us to abort the cmd search.
455 */
456 return (A_UINVALID);
457 }
458 while (*p++ != '\0')
459 continue;
460 while (*p == A_SKIP)
461 p++;
462 if (*p & A_EXTRA)
463 while (*++p != '\0')
464 continue;
465 q = cmd-1;
466 }
467 }
468 /*
469 * No match found in the entire command table.
470 */
471 return (A_INVALID);
472}
473
474/*
475 * Decode a command character and return the associated action.
476 * The "extra" string, if any, is returned in sp.
477 */
478 static int
479cmd_decode(tlist, cmd, sp)
480 struct tablelist *tlist;
481 char *cmd;
482 char **sp;
483{
484 register struct tablelist *t;
485 register int action = A_INVALID;
486
487 /*
488 * Search thru all the command tables.
489 * Stop when we find an action which is not A_INVALID.
490 */
491 for (t = tlist; t != NULL; t = t->t_next)
492 {
493 action = cmd_search(cmd, t->t_start, t->t_end, sp);
494 if (action != A_INVALID)
495 break;
496 }
497 if (action == A_UINVALID)
498 action = A_INVALID;
499 return (action);
500}
501
502/*
503 * Decode a command from the cmdtables list.
504 */
505 public int
506fcmd_decode(cmd, sp)
507 char *cmd;
508 char **sp;
509{
510 return (cmd_decode(list_fcmd_tables, cmd, sp));
511}
512
513/*
514 * Decode a command from the edittables list.
515 */
516 public int
517ecmd_decode(cmd, sp)
518 char *cmd;
519 char **sp;
520{
521 return (cmd_decode(list_ecmd_tables, cmd, sp));
522}
523
524/*
525 * Get the value of an environment variable.
526 * Looks first in the lesskey file, then in the real environment.
527 */
528 public char *
529lgetenv(var)
530 char *var;
531{
532 int a;
533 char *s;
534
535 a = cmd_decode(list_var_tables, var, &s);
536 if (a == EV_OK)
537 return (s);
538 s = getenv(var);
539 if (s != NULL && *s != '\0')
540 return (s);
541 a = cmd_decode(list_sysvar_tables, var, &s);
542 if (a == EV_OK)
543 return (s);
544 return (NULL);
545}
546
547#if USERFILE
548/*
549 * Get an "integer" from a lesskey file.
550 * Integers are stored in a funny format:
551 * two bytes, low order first, in radix KRADIX.
552 */
553 static int
554gint(sp)
555 char **sp;
556{
557 int n;
558
559 n = *(*sp)++;
560 n += *(*sp)++ * KRADIX;
561 return (n);
562}
563
564/*
565 * Process an old (pre-v241) lesskey file.
566 */
567 static int
568old_lesskey(buf, len)
569 char *buf;
570 int len;
571{
572 /*
573 * Old-style lesskey file.
574 * The file must end with either
575 * ...,cmd,0,action
576 * or ...,cmd,0,action|A_EXTRA,string,0
577 * So the last byte or the second to last byte must be zero.
578 */
579 if (buf[len-1] != '\0' && buf[len-2] != '\0')
580 return (-1);
581 add_fcmd_table(buf, len);
582 return (0);
583}
584
585/*
586 * Process a new (post-v241) lesskey file.
587 */
588 static int
589new_lesskey(buf, len, sysvar)
590 char *buf;
591 int len;
592 int sysvar;
593{
594 char *p;
595 register int c;
596 register int n;
597
598 /*
599 * New-style lesskey file.
600 * Extract the pieces.
601 */
602 if (buf[len-3] != C0_END_LESSKEY_MAGIC ||
603 buf[len-2] != C1_END_LESSKEY_MAGIC ||
604 buf[len-1] != C2_END_LESSKEY_MAGIC)
605 return (-1);
606 p = buf + 4;
607 for (;;)
608 {
609 c = *p++;
610 switch (c)
611 {
612 case CMD_SECTION:
613 n = gint(&p);
614 add_fcmd_table(p, n);
615 p += n;
616 break;
617 case EDIT_SECTION:
618 n = gint(&p);
619 add_ecmd_table(p, n);
620 p += n;
621 break;
622 case VAR_SECTION:
623 n = gint(&p);
624 add_var_table((sysvar) ?
625 &list_sysvar_tables : &list_var_tables, p, n);
626 p += n;
627 break;
628 case END_SECTION:
629 return (0);
630 default:
631 /*
632 * Unrecognized section type.
633 */
634 return (-1);
635 }
636 }
637}
638
639/*
640 * Set up a user command table, based on a "lesskey" file.
641 */
642 public int
643lesskey(filename, sysvar)
644 char *filename;
645 int sysvar;
646{
647 register char *buf;
648 register POSITION len;
649 register long n;
650 register int f;
651
652 if (secure)
653 return (1);
654 /*
655 * Try to open the lesskey file.
656 */
657 filename = shell_unquote(filename);
658 f = open(filename, OPEN_READ);
659 free(filename);
660 if (f < 0)
661 return (1);
662
663 /*
664 * Read the file into a buffer.
665 * We first figure out the size of the file and allocate space for it.
666 * {{ Minimal error checking is done here.
667 * A garbage .less file will produce strange results.
668 * To avoid a large amount of error checking code here, we
669 * rely on the lesskey program to generate a good .less file. }}
670 */
671 len = filesize(f);
672 if (len == NULL_POSITION || len < 3)
673 {
674 /*
675 * Bad file (valid file must have at least 3 chars).
676 */
677 close(f);
678 return (-1);
679 }
680 if ((buf = (char *) calloc((int)len, sizeof(char))) == NULL)
681 {
682 close(f);
683 return (-1);
684 }
685 if (lseek(f, (off_t)0, SEEK_SET) == BAD_LSEEK)
686 {
687 free(buf);
688 close(f);
689 return (-1);
690 }
691 n = read(f, buf, (unsigned int) len);
692 close(f);
693 if (n != len)
694 {
695 free(buf);
696 return (-1);
697 }
698
699 /*
700 * Figure out if this is an old-style (before version 241)
701 * or new-style lesskey file format.
702 */
703 if (buf[0] != C0_LESSKEY_MAGIC || buf[1] != C1_LESSKEY_MAGIC ||
704 buf[2] != C2_LESSKEY_MAGIC || buf[3] != C3_LESSKEY_MAGIC)
705 return (old_lesskey(buf, (int)len));
706 return (new_lesskey(buf, (int)len, sysvar));
707}
708
709/*
710 * Add the standard lesskey file "$HOME/.less"
711 */
712 public void
713add_hometable(envname, def_filename, sysvar)
714 char *envname;
715 char *def_filename;
716 int sysvar;
717{
718 char *filename;
719 PARG parg;
720
721 if (envname != NULL && (filename = lgetenv(envname)) != NULL)
722 filename = save(filename);
723 else if (sysvar)
724 filename = save(def_filename);
725 else
726 filename = homefile(def_filename);
727 if (filename == NULL)
728 return;
729 if (lesskey(filename, sysvar) < 0)
730 {
731 parg.p_string = filename;
732 error("Cannot use lesskey file \"%s\"", &parg);
733 }
734 free(filename);
735}
736#endif
737
738/*
739 * See if a char is a special line-editing command.
740 */
741 public int
742editchar(c, flags)
743 int c;
744 int flags;
745{
746 int action;
747 int nch;
748 char *s;
749 char usercmd[MAX_CMDLEN+1];
750
751 /*
752 * An editing character could actually be a sequence of characters;
753 * for example, an escape sequence sent by pressing the uparrow key.
754 * To match the editing string, we use the command decoder
755 * but give it the edit-commands command table
756 * This table is constructed to match the user's keyboard.
757 */
758 if (c == erase_char || c == erase2_char)
759 return (EC_BACKSPACE);
760 if (c == kill_char)
761 return (EC_LINEKILL);
762
763 /*
764 * Collect characters in a buffer.
765 * Start with the one we have, and get more if we need them.
766 */
767 nch = 0;
768 do {
769 if (nch > 0)
770 c = getcc();
771 usercmd[nch] = c;
772 usercmd[nch+1] = '\0';
773 nch++;
774 action = ecmd_decode(usercmd, &s);
775 } while (action == A_PREFIX);
776
777 if (flags & EC_NORIGHTLEFT)
778 {
779 switch (action)
780 {
781 case EC_RIGHT:
782 case EC_LEFT:
783 action = A_INVALID;
784 break;
785 }
786 }
787#if CMD_HISTORY
788 if (flags & EC_NOHISTORY)
789 {
790 /*
791 * The caller says there is no history list.
792 * Reject any history-manipulation action.
793 */
794 switch (action)
795 {
796 case EC_UP:
797 case EC_DOWN:
798 action = A_INVALID;
799 break;
800 }
801 }
802#endif
803#if TAB_COMPLETE_FILENAME
804 if (flags & EC_NOCOMPLETE)
805 {
806 /*
807 * The caller says we don't want any filename completion cmds.
808 * Reject them.
809 */
810 switch (action)
811 {
812 case EC_F_COMPLETE:
813 case EC_B_COMPLETE:
814 case EC_EXPAND:
815 action = A_INVALID;
816 break;
817 }
818 }
819#endif
820 if ((flags & EC_PEEK) || action == A_INVALID)
821 {
822 /*
823 * We're just peeking, or we didn't understand the command.
824 * Unget all the characters we read in the loop above.
825 * This does NOT include the original character that was
826 * passed in as a parameter.
827 */
828 while (nch > 1)
829 {
830 ungetcc(usercmd[--nch]);
831 }
832 } else
833 {
834 if (s != NULL)
835 ungetsc(s);
836 }
837 return action;
838}
839
2 * Copyright (C) 1984-2007 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 about less, or for information on how to
8 * contact the author, see the README file.
9 */
10
11
12/*
13 * Routines to decode user commands.
14 *
15 * This is all table driven.
16 * A command table is a sequence of command descriptors.
17 * Each command descriptor is a sequence of bytes with the following format:
18 * <c1><c2>...<cN><0><action>
19 * The characters c1,c2,...,cN are the command string; that is,
20 * the characters which the user must type.
21 * It is terminated by a null <0> byte.
22 * The byte after the null byte is the action code associated
23 * with the command string.
24 * If an action byte is OR-ed with A_EXTRA, this indicates
25 * that the option byte is followed by an extra string.
26 *
27 * There may be many command tables.
28 * The first (default) table is built-in.
29 * Other tables are read in from "lesskey" files.
30 * All the tables are linked together and are searched in order.
31 */
32
33#include "less.h"
34#include "cmd.h"
35#include "lesskey.h"
36
37extern int erase_char, erase2_char, kill_char;
38extern int secure;
39
40#define SK(k) \
41 SK_SPECIAL_KEY, (k), 6, 1, 1, 1
42/*
43 * Command table is ordered roughly according to expected
44 * frequency of use, so the common commands are near the beginning.
45 */
46
47static unsigned char cmdtable[] =
48{
49 '\r',0, A_F_LINE,
50 '\n',0, A_F_LINE,
51 'e',0, A_F_LINE,
52 'j',0, A_F_LINE,
53 SK(SK_DOWN_ARROW),0, A_F_LINE,
54 CONTROL('E'),0, A_F_LINE,
55 CONTROL('N'),0, A_F_LINE,
56 'k',0, A_B_LINE,
57 'y',0, A_B_LINE,
58 CONTROL('Y'),0, A_B_LINE,
59 SK(SK_CONTROL_K),0, A_B_LINE,
60 CONTROL('P'),0, A_B_LINE,
61 SK(SK_UP_ARROW),0, A_B_LINE,
62 'J',0, A_FF_LINE,
63 'K',0, A_BF_LINE,
64 'Y',0, A_BF_LINE,
65 'd',0, A_F_SCROLL,
66 CONTROL('D'),0, A_F_SCROLL,
67 'u',0, A_B_SCROLL,
68 CONTROL('U'),0, A_B_SCROLL,
69 ' ',0, A_F_SCREEN,
70 'f',0, A_F_SCREEN,
71 CONTROL('F'),0, A_F_SCREEN,
72 CONTROL('V'),0, A_F_SCREEN,
73 SK(SK_PAGE_DOWN),0, A_F_SCREEN,
74 'b',0, A_B_SCREEN,
75 CONTROL('B'),0, A_B_SCREEN,
76 ESC,'v',0, A_B_SCREEN,
77 SK(SK_PAGE_UP),0, A_B_SCREEN,
78 'z',0, A_F_WINDOW,
79 'w',0, A_B_WINDOW,
80 ESC,' ',0, A_FF_SCREEN,
81 'F',0, A_F_FOREVER,
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 SK(SK_RIGHT_ARROW),0, A_RSHIFT,
98 SK(SK_LEFT_ARROW),0, A_LSHIFT,
99 '{',0, A_F_BRACKET|A_EXTRA, '{','}',0,
100 '}',0, A_B_BRACKET|A_EXTRA, '{','}',0,
101 '(',0, A_F_BRACKET|A_EXTRA, '(',')',0,
102 ')',0, A_B_BRACKET|A_EXTRA, '(',')',0,
103 '[',0, A_F_BRACKET|A_EXTRA, '[',']',0,
104 ']',0, A_B_BRACKET|A_EXTRA, '[',']',0,
105 ESC,CONTROL('F'),0, A_F_BRACKET,
106 ESC,CONTROL('B'),0, A_B_BRACKET,
107 'G',0, A_GOEND,
108 ESC,'>',0, A_GOEND,
109 '>',0, A_GOEND,
110 SK(SK_END),0, A_GOEND,
111 'P',0, A_GOPOS,
112
113 '0',0, A_DIGIT,
114 '1',0, A_DIGIT,
115 '2',0, A_DIGIT,
116 '3',0, A_DIGIT,
117 '4',0, A_DIGIT,
118 '5',0, A_DIGIT,
119 '6',0, A_DIGIT,
120 '7',0, A_DIGIT,
121 '8',0, A_DIGIT,
122 '9',0, A_DIGIT,
123 '.',0, A_DIGIT,
124
125 '=',0, A_STAT,
126 CONTROL('G'),0, A_STAT,
127 ':','f',0, A_STAT,
128 '/',0, A_F_SEARCH,
129 '?',0, A_B_SEARCH,
130 ESC,'/',0, A_F_SEARCH|A_EXTRA, '*',0,
131 ESC,'?',0, A_B_SEARCH|A_EXTRA, '*',0,
132 'n',0, A_AGAIN_SEARCH,
133 ESC,'n',0, A_T_AGAIN_SEARCH,
134 'N',0, A_REVERSE_SEARCH,
135 ESC,'N',0, A_T_REVERSE_SEARCH,
136 'm',0, A_SETMARK,
137 '\'',0, A_GOMARK,
138 CONTROL('X'),CONTROL('X'),0, A_GOMARK,
139 'E',0, A_EXAMINE,
140 ':','e',0, A_EXAMINE,
141 CONTROL('X'),CONTROL('V'),0, A_EXAMINE,
142 ':','n',0, A_NEXT_FILE,
143 ':','p',0, A_PREV_FILE,
144 't',0, A_NEXT_TAG,
145 'T',0, A_PREV_TAG,
146 ':','x',0, A_INDEX_FILE,
147 ':','d',0, A_REMOVE_FILE,
148 '-',0, A_OPT_TOGGLE,
149 ':','t',0, A_OPT_TOGGLE|A_EXTRA, 't',0,
150 's',0, A_OPT_TOGGLE|A_EXTRA, 'o',0,
151 '_',0, A_DISP_OPTION,
152 '|',0, A_PIPE,
153 'v',0, A_VISUAL,
154 '!',0, A_SHELL,
155 '+',0, A_FIRSTCMD,
156
157 'H',0, A_HELP,
158 'h',0, A_HELP,
159 SK(SK_F1),0, A_HELP,
160 'V',0, A_VERSION,
161 'q',0, A_QUIT,
162 'Q',0, A_QUIT,
163 ':','q',0, A_QUIT,
164 ':','Q',0, A_QUIT,
165 'Z','Z',0, A_QUIT
166};
167
168static unsigned char edittable[] =
169{
170 '\t',0, EC_F_COMPLETE, /* TAB */
171 '\17',0, EC_B_COMPLETE, /* BACKTAB */
172 SK(SK_BACKTAB),0, EC_B_COMPLETE, /* BACKTAB */
173 ESC,'\t',0, EC_B_COMPLETE, /* ESC TAB */
174 CONTROL('L'),0, EC_EXPAND, /* CTRL-L */
175 CONTROL('V'),0, EC_LITERAL, /* BACKSLASH */
176 CONTROL('A'),0, EC_LITERAL, /* BACKSLASH */
177 ESC,'l',0, EC_RIGHT, /* ESC l */
178 SK(SK_RIGHT_ARROW),0, EC_RIGHT, /* RIGHTARROW */
179 ESC,'h',0, EC_LEFT, /* ESC h */
180 SK(SK_LEFT_ARROW),0, EC_LEFT, /* LEFTARROW */
181 ESC,'b',0, EC_W_LEFT, /* ESC b */
182 ESC,SK(SK_LEFT_ARROW),0, EC_W_LEFT, /* ESC LEFTARROW */
183 SK(SK_CTL_LEFT_ARROW),0, EC_W_LEFT, /* CTRL-LEFTARROW */
184 ESC,'w',0, EC_W_RIGHT, /* ESC w */
185 ESC,SK(SK_RIGHT_ARROW),0, EC_W_RIGHT, /* ESC RIGHTARROW */
186 SK(SK_CTL_RIGHT_ARROW),0, EC_W_RIGHT, /* CTRL-RIGHTARROW */
187 ESC,'i',0, EC_INSERT, /* ESC i */
188 SK(SK_INSERT),0, EC_INSERT, /* INSERT */
189 ESC,'x',0, EC_DELETE, /* ESC x */
190 SK(SK_DELETE),0, EC_DELETE, /* DELETE */
191 ESC,'X',0, EC_W_DELETE, /* ESC X */
192 ESC,SK(SK_DELETE),0, EC_W_DELETE, /* ESC DELETE */
193 SK(SK_CTL_DELETE),0, EC_W_DELETE, /* CTRL-DELETE */
194 SK(SK_CTL_BACKSPACE),0, EC_W_BACKSPACE, /* CTRL-BACKSPACE */
195 ESC,'\b',0, EC_W_BACKSPACE, /* ESC BACKSPACE */
196 ESC,'0',0, EC_HOME, /* ESC 0 */
197 SK(SK_HOME),0, EC_HOME, /* HOME */
198 ESC,'$',0, EC_END, /* ESC $ */
199 SK(SK_END),0, EC_END, /* END */
200 ESC,'k',0, EC_UP, /* ESC k */
201 SK(SK_UP_ARROW),0, EC_UP, /* UPARROW */
202 ESC,'j',0, EC_DOWN, /* ESC j */
203 SK(SK_DOWN_ARROW),0, EC_DOWN, /* DOWNARROW */
204};
205
206/*
207 * Structure to support a list of command tables.
208 */
209struct tablelist
210{
211 struct tablelist *t_next;
212 char *t_start;
213 char *t_end;
214};
215
216/*
217 * List of command tables and list of line-edit tables.
218 */
219static struct tablelist *list_fcmd_tables = NULL;
220static struct tablelist *list_ecmd_tables = NULL;
221static struct tablelist *list_var_tables = NULL;
222static struct tablelist *list_sysvar_tables = NULL;
223
224
225/*
226 * Expand special key abbreviations in a command table.
227 */
228 static void
229expand_special_keys(table, len)
230 char *table;
231 int len;
232{
233 register char *fm;
234 register char *to;
235 register int a;
236 char *repl;
237 int klen;
238
239 for (fm = table; fm < table + len; )
240 {
241 /*
242 * Rewrite each command in the table with any
243 * special key abbreviations expanded.
244 */
245 for (to = fm; *fm != '\0'; )
246 {
247 if (*fm != SK_SPECIAL_KEY)
248 {
249 *to++ = *fm++;
250 continue;
251 }
252 /*
253 * After SK_SPECIAL_KEY, next byte is the type
254 * of special key (one of the SK_* contants),
255 * and the byte after that is the number of bytes,
256 * N, reserved by the abbreviation (including the
257 * SK_SPECIAL_KEY and key type bytes).
258 * Replace all N bytes with the actual bytes
259 * output by the special key on this terminal.
260 */
261 repl = special_key_str(fm[1]);
262 klen = fm[2] & 0377;
263 fm += klen;
264 if (repl == NULL || (int) strlen(repl) > klen)
265 repl = "\377";
266 while (*repl != '\0')
267 *to++ = *repl++;
268 }
269 *to++ = '\0';
270 /*
271 * Fill any unused bytes between end of command and
272 * the action byte with A_SKIP.
273 */
274 while (to <= fm)
275 *to++ = A_SKIP;
276 fm++;
277 a = *fm++ & 0377;
278 if (a & A_EXTRA)
279 {
280 while (*fm++ != '\0')
281 continue;
282 }
283 }
284}
285
286/*
287 * Initialize the command lists.
288 */
289 public void
290init_cmds()
291{
292 /*
293 * Add the default command tables.
294 */
295 add_fcmd_table((char*)cmdtable, sizeof(cmdtable));
296 add_ecmd_table((char*)edittable, sizeof(edittable));
297#if USERFILE
298 /*
299 * For backwards compatibility,
300 * try to add tables in the OLD system lesskey file.
301 */
302#ifdef BINDIR
303 add_hometable(NULL, BINDIR "/.sysless", 1);
304#endif
305 /*
306 * Try to add the tables in the system lesskey file.
307 */
308 add_hometable("LESSKEY_SYSTEM", LESSKEYFILE_SYS, 1);
309 /*
310 * Try to add the tables in the standard lesskey file "$HOME/.less".
311 */
312 add_hometable("LESSKEY", LESSKEYFILE, 0);
313#endif
314}
315
316/*
317 * Add a command table.
318 */
319 static int
320add_cmd_table(tlist, buf, len)
321 struct tablelist **tlist;
322 char *buf;
323 int len;
324{
325 register struct tablelist *t;
326
327 if (len == 0)
328 return (0);
329 /*
330 * Allocate a tablelist structure, initialize it,
331 * and link it into the list of tables.
332 */
333 if ((t = (struct tablelist *)
334 calloc(1, sizeof(struct tablelist))) == NULL)
335 {
336 return (-1);
337 }
338 expand_special_keys(buf, len);
339 t->t_start = buf;
340 t->t_end = buf + len;
341 t->t_next = *tlist;
342 *tlist = t;
343 return (0);
344}
345
346/*
347 * Add a command table.
348 */
349 public void
350add_fcmd_table(buf, len)
351 char *buf;
352 int len;
353{
354 if (add_cmd_table(&list_fcmd_tables, buf, len) < 0)
355 error("Warning: some commands disabled", NULL_PARG);
356}
357
358/*
359 * Add an editing command table.
360 */
361 public void
362add_ecmd_table(buf, len)
363 char *buf;
364 int len;
365{
366 if (add_cmd_table(&list_ecmd_tables, buf, len) < 0)
367 error("Warning: some edit commands disabled", NULL_PARG);
368}
369
370/*
371 * Add an environment variable table.
372 */
373 static void
374add_var_table(tlist, buf, len)
375 struct tablelist **tlist;
376 char *buf;
377 int len;
378{
379 if (add_cmd_table(tlist, buf, len) < 0)
380 error("Warning: environment variables from lesskey file unavailable", NULL_PARG);
381}
382
383/*
384 * Search a single command table for the command string in cmd.
385 */
386 static int
387cmd_search(cmd, table, endtable, sp)
388 char *cmd;
389 char *table;
390 char *endtable;
391 char **sp;
392{
393 register char *p;
394 register char *q;
395 register int a;
396
397 *sp = NULL;
398 for (p = table, q = cmd; p < endtable; p++, q++)
399 {
400 if (*p == *q)
401 {
402 /*
403 * Current characters match.
404 * If we're at the end of the string, we've found it.
405 * Return the action code, which is the character
406 * after the null at the end of the string
407 * in the command table.
408 */
409 if (*p == '\0')
410 {
411 a = *++p & 0377;
412 while (a == A_SKIP)
413 a = *++p & 0377;
414 if (a == A_END_LIST)
415 {
416 /*
417 * We get here only if the original
418 * cmd string passed in was empty ("").
419 * I don't think that can happen,
420 * but just in case ...
421 */
422 return (A_UINVALID);
423 }
424 /*
425 * Check for an "extra" string.
426 */
427 if (a & A_EXTRA)
428 {
429 *sp = ++p;
430 a &= ~A_EXTRA;
431 }
432 return (a);
433 }
434 } else if (*q == '\0')
435 {
436 /*
437 * Hit the end of the user's command,
438 * but not the end of the string in the command table.
439 * The user's command is incomplete.
440 */
441 return (A_PREFIX);
442 } else
443 {
444 /*
445 * Not a match.
446 * Skip ahead to the next command in the
447 * command table, and reset the pointer
448 * to the beginning of the user's command.
449 */
450 if (*p == '\0' && p[1] == A_END_LIST)
451 {
452 /*
453 * A_END_LIST is a special marker that tells
454 * us to abort the cmd search.
455 */
456 return (A_UINVALID);
457 }
458 while (*p++ != '\0')
459 continue;
460 while (*p == A_SKIP)
461 p++;
462 if (*p & A_EXTRA)
463 while (*++p != '\0')
464 continue;
465 q = cmd-1;
466 }
467 }
468 /*
469 * No match found in the entire command table.
470 */
471 return (A_INVALID);
472}
473
474/*
475 * Decode a command character and return the associated action.
476 * The "extra" string, if any, is returned in sp.
477 */
478 static int
479cmd_decode(tlist, cmd, sp)
480 struct tablelist *tlist;
481 char *cmd;
482 char **sp;
483{
484 register struct tablelist *t;
485 register int action = A_INVALID;
486
487 /*
488 * Search thru all the command tables.
489 * Stop when we find an action which is not A_INVALID.
490 */
491 for (t = tlist; t != NULL; t = t->t_next)
492 {
493 action = cmd_search(cmd, t->t_start, t->t_end, sp);
494 if (action != A_INVALID)
495 break;
496 }
497 if (action == A_UINVALID)
498 action = A_INVALID;
499 return (action);
500}
501
502/*
503 * Decode a command from the cmdtables list.
504 */
505 public int
506fcmd_decode(cmd, sp)
507 char *cmd;
508 char **sp;
509{
510 return (cmd_decode(list_fcmd_tables, cmd, sp));
511}
512
513/*
514 * Decode a command from the edittables list.
515 */
516 public int
517ecmd_decode(cmd, sp)
518 char *cmd;
519 char **sp;
520{
521 return (cmd_decode(list_ecmd_tables, cmd, sp));
522}
523
524/*
525 * Get the value of an environment variable.
526 * Looks first in the lesskey file, then in the real environment.
527 */
528 public char *
529lgetenv(var)
530 char *var;
531{
532 int a;
533 char *s;
534
535 a = cmd_decode(list_var_tables, var, &s);
536 if (a == EV_OK)
537 return (s);
538 s = getenv(var);
539 if (s != NULL && *s != '\0')
540 return (s);
541 a = cmd_decode(list_sysvar_tables, var, &s);
542 if (a == EV_OK)
543 return (s);
544 return (NULL);
545}
546
547#if USERFILE
548/*
549 * Get an "integer" from a lesskey file.
550 * Integers are stored in a funny format:
551 * two bytes, low order first, in radix KRADIX.
552 */
553 static int
554gint(sp)
555 char **sp;
556{
557 int n;
558
559 n = *(*sp)++;
560 n += *(*sp)++ * KRADIX;
561 return (n);
562}
563
564/*
565 * Process an old (pre-v241) lesskey file.
566 */
567 static int
568old_lesskey(buf, len)
569 char *buf;
570 int len;
571{
572 /*
573 * Old-style lesskey file.
574 * The file must end with either
575 * ...,cmd,0,action
576 * or ...,cmd,0,action|A_EXTRA,string,0
577 * So the last byte or the second to last byte must be zero.
578 */
579 if (buf[len-1] != '\0' && buf[len-2] != '\0')
580 return (-1);
581 add_fcmd_table(buf, len);
582 return (0);
583}
584
585/*
586 * Process a new (post-v241) lesskey file.
587 */
588 static int
589new_lesskey(buf, len, sysvar)
590 char *buf;
591 int len;
592 int sysvar;
593{
594 char *p;
595 register int c;
596 register int n;
597
598 /*
599 * New-style lesskey file.
600 * Extract the pieces.
601 */
602 if (buf[len-3] != C0_END_LESSKEY_MAGIC ||
603 buf[len-2] != C1_END_LESSKEY_MAGIC ||
604 buf[len-1] != C2_END_LESSKEY_MAGIC)
605 return (-1);
606 p = buf + 4;
607 for (;;)
608 {
609 c = *p++;
610 switch (c)
611 {
612 case CMD_SECTION:
613 n = gint(&p);
614 add_fcmd_table(p, n);
615 p += n;
616 break;
617 case EDIT_SECTION:
618 n = gint(&p);
619 add_ecmd_table(p, n);
620 p += n;
621 break;
622 case VAR_SECTION:
623 n = gint(&p);
624 add_var_table((sysvar) ?
625 &list_sysvar_tables : &list_var_tables, p, n);
626 p += n;
627 break;
628 case END_SECTION:
629 return (0);
630 default:
631 /*
632 * Unrecognized section type.
633 */
634 return (-1);
635 }
636 }
637}
638
639/*
640 * Set up a user command table, based on a "lesskey" file.
641 */
642 public int
643lesskey(filename, sysvar)
644 char *filename;
645 int sysvar;
646{
647 register char *buf;
648 register POSITION len;
649 register long n;
650 register int f;
651
652 if (secure)
653 return (1);
654 /*
655 * Try to open the lesskey file.
656 */
657 filename = shell_unquote(filename);
658 f = open(filename, OPEN_READ);
659 free(filename);
660 if (f < 0)
661 return (1);
662
663 /*
664 * Read the file into a buffer.
665 * We first figure out the size of the file and allocate space for it.
666 * {{ Minimal error checking is done here.
667 * A garbage .less file will produce strange results.
668 * To avoid a large amount of error checking code here, we
669 * rely on the lesskey program to generate a good .less file. }}
670 */
671 len = filesize(f);
672 if (len == NULL_POSITION || len < 3)
673 {
674 /*
675 * Bad file (valid file must have at least 3 chars).
676 */
677 close(f);
678 return (-1);
679 }
680 if ((buf = (char *) calloc((int)len, sizeof(char))) == NULL)
681 {
682 close(f);
683 return (-1);
684 }
685 if (lseek(f, (off_t)0, SEEK_SET) == BAD_LSEEK)
686 {
687 free(buf);
688 close(f);
689 return (-1);
690 }
691 n = read(f, buf, (unsigned int) len);
692 close(f);
693 if (n != len)
694 {
695 free(buf);
696 return (-1);
697 }
698
699 /*
700 * Figure out if this is an old-style (before version 241)
701 * or new-style lesskey file format.
702 */
703 if (buf[0] != C0_LESSKEY_MAGIC || buf[1] != C1_LESSKEY_MAGIC ||
704 buf[2] != C2_LESSKEY_MAGIC || buf[3] != C3_LESSKEY_MAGIC)
705 return (old_lesskey(buf, (int)len));
706 return (new_lesskey(buf, (int)len, sysvar));
707}
708
709/*
710 * Add the standard lesskey file "$HOME/.less"
711 */
712 public void
713add_hometable(envname, def_filename, sysvar)
714 char *envname;
715 char *def_filename;
716 int sysvar;
717{
718 char *filename;
719 PARG parg;
720
721 if (envname != NULL && (filename = lgetenv(envname)) != NULL)
722 filename = save(filename);
723 else if (sysvar)
724 filename = save(def_filename);
725 else
726 filename = homefile(def_filename);
727 if (filename == NULL)
728 return;
729 if (lesskey(filename, sysvar) < 0)
730 {
731 parg.p_string = filename;
732 error("Cannot use lesskey file \"%s\"", &parg);
733 }
734 free(filename);
735}
736#endif
737
738/*
739 * See if a char is a special line-editing command.
740 */
741 public int
742editchar(c, flags)
743 int c;
744 int flags;
745{
746 int action;
747 int nch;
748 char *s;
749 char usercmd[MAX_CMDLEN+1];
750
751 /*
752 * An editing character could actually be a sequence of characters;
753 * for example, an escape sequence sent by pressing the uparrow key.
754 * To match the editing string, we use the command decoder
755 * but give it the edit-commands command table
756 * This table is constructed to match the user's keyboard.
757 */
758 if (c == erase_char || c == erase2_char)
759 return (EC_BACKSPACE);
760 if (c == kill_char)
761 return (EC_LINEKILL);
762
763 /*
764 * Collect characters in a buffer.
765 * Start with the one we have, and get more if we need them.
766 */
767 nch = 0;
768 do {
769 if (nch > 0)
770 c = getcc();
771 usercmd[nch] = c;
772 usercmd[nch+1] = '\0';
773 nch++;
774 action = ecmd_decode(usercmd, &s);
775 } while (action == A_PREFIX);
776
777 if (flags & EC_NORIGHTLEFT)
778 {
779 switch (action)
780 {
781 case EC_RIGHT:
782 case EC_LEFT:
783 action = A_INVALID;
784 break;
785 }
786 }
787#if CMD_HISTORY
788 if (flags & EC_NOHISTORY)
789 {
790 /*
791 * The caller says there is no history list.
792 * Reject any history-manipulation action.
793 */
794 switch (action)
795 {
796 case EC_UP:
797 case EC_DOWN:
798 action = A_INVALID;
799 break;
800 }
801 }
802#endif
803#if TAB_COMPLETE_FILENAME
804 if (flags & EC_NOCOMPLETE)
805 {
806 /*
807 * The caller says we don't want any filename completion cmds.
808 * Reject them.
809 */
810 switch (action)
811 {
812 case EC_F_COMPLETE:
813 case EC_B_COMPLETE:
814 case EC_EXPAND:
815 action = A_INVALID;
816 break;
817 }
818 }
819#endif
820 if ((flags & EC_PEEK) || action == A_INVALID)
821 {
822 /*
823 * We're just peeking, or we didn't understand the command.
824 * Unget all the characters we read in the loop above.
825 * This does NOT include the original character that was
826 * passed in as a parameter.
827 */
828 while (nch > 1)
829 {
830 ungetcc(usercmd[--nch]);
831 }
832 } else
833 {
834 if (s != NULL)
835 ungetsc(s);
836 }
837 return action;
838}
839