1 /*
2 * Copyright (C) 1984-2002 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
37 extern int erase_char, kill_char;
38 extern 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
47 static 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
124 '=',0, A_STAT,
125 CONTROL('G'),0, A_STAT,
126 ':','f',0, A_STAT,
127 '/',0, A_F_SEARCH,
128 '?',0, A_B_SEARCH,
129 ESC,'/',0, A_F_SEARCH|A_EXTRA, '*',0,
130 ESC,'?',0, A_B_SEARCH|A_EXTRA, '*',0,
131 'n',0, A_AGAIN_SEARCH,
132 ESC,'n',0, A_T_AGAIN_SEARCH,
133 'N',0, A_REVERSE_SEARCH,
134 ESC,'N',0, A_T_REVERSE_SEARCH,
135 'm',0, A_SETMARK,
136 '\'',0, A_GOMARK,
137 CONTROL('X'),CONTROL('X'),0, A_GOMARK,
138 'E',0, A_EXAMINE,
139 ':','e',0, A_EXAMINE,
140 CONTROL('X'),CONTROL('V'),0, A_EXAMINE,
141 ':','n',0, A_NEXT_FILE,
142 ':','p',0, A_PREV_FILE,
143 't',0, A_NEXT_TAG,
144 'T',0, A_PREV_TAG,
145 ':','x',0, A_INDEX_FILE,
146 ':','d',0, A_REMOVE_FILE,
147 '-',0, A_OPT_TOGGLE,
148 ':','t',0, A_OPT_TOGGLE|A_EXTRA, 't',0,
149 's',0, A_OPT_TOGGLE|A_EXTRA, 'o',0,
150 '_',0, A_DISP_OPTION,
151 '|',0, A_PIPE,
152 'v',0, A_VISUAL,
153 '!',0, A_SHELL,
154 '+',0, A_FIRSTCMD,
155
156 'H',0, A_HELP,
157 'h',0, A_HELP,
158 SK(SK_F1),0, A_HELP,
159 'V',0, A_VERSION,
160 'q',0, A_QUIT,
161 'Q',0, A_QUIT,
162 ':','q',0, A_QUIT,
163 ':','Q',0, A_QUIT,
164 'Z','Z',0, A_QUIT
165 };
166
167 static unsigned char edittable[] =
168 {
169 '\t',0, EC_F_COMPLETE, /* TAB */
170 '\17',0, EC_B_COMPLETE, /* BACKTAB */
171 SK(SK_BACKTAB),0, EC_B_COMPLETE, /* BACKTAB */
172 ESC,'\t',0, EC_B_COMPLETE, /* ESC TAB */
173 CONTROL('L'),0, EC_EXPAND, /* CTRL-L */
174 CONTROL('V'),0, EC_LITERAL, /* BACKSLASH */
175 CONTROL('A'),0, EC_LITERAL, /* BACKSLASH */
176 ESC,'l',0, EC_RIGHT, /* ESC l */
177 SK(SK_RIGHT_ARROW),0, EC_RIGHT, /* RIGHTARROW */
178 ESC,'h',0, EC_LEFT, /* ESC h */
179 SK(SK_LEFT_ARROW),0, EC_LEFT, /* LEFTARROW */
180 ESC,'b',0, EC_W_LEFT, /* ESC b */
181 ESC,SK(SK_LEFT_ARROW),0, EC_W_LEFT, /* ESC LEFTARROW */
182 SK(SK_CTL_LEFT_ARROW),0, EC_W_LEFT, /* CTRL-LEFTARROW */
183 ESC,'w',0, EC_W_RIGHT, /* ESC w */
184 ESC,SK(SK_RIGHT_ARROW),0, EC_W_RIGHT, /* ESC RIGHTARROW */
185 SK(SK_CTL_RIGHT_ARROW),0, EC_W_RIGHT, /* CTRL-RIGHTARROW */
186 ESC,'i',0, EC_INSERT, /* ESC i */
187 SK(SK_INSERT),0, EC_INSERT, /* INSERT */
188 ESC,'x',0, EC_DELETE, /* ESC x */
189 SK(SK_DELETE),0, EC_DELETE, /* DELETE */
190 ESC,'X',0, EC_W_DELETE, /* ESC X */
191 ESC,SK(SK_DELETE),0, EC_W_DELETE, /* ESC DELETE */
192 SK(SK_CTL_DELETE),0, EC_W_DELETE, /* CTRL-DELETE */
193 SK(SK_CTL_BACKSPACE),0, EC_W_BACKSPACE, /* CTRL-BACKSPACE */
194 ESC,'\b',0, EC_W_BACKSPACE, /* ESC BACKSPACE */
195 ESC,'0',0, EC_HOME, /* ESC 0 */
196 SK(SK_HOME),0, EC_HOME, /* HOME */
197 ESC,'$',0, EC_END, /* ESC $ */
198 SK(SK_END),0, EC_END, /* END */
199 ESC,'k',0, EC_UP, /* ESC k */
200 SK(SK_UP_ARROW),0, EC_UP, /* UPARROW */
201 ESC,'j',0, EC_DOWN, /* ESC j */
202 SK(SK_DOWN_ARROW),0, EC_DOWN, /* DOWNARROW */
203 };
204
205 /*
206 * Structure to support a list of command tables.
207 */
208 struct tablelist
209 {
210 struct tablelist *t_next;
211 char *t_start;
212 char *t_end;
213 };
214
215 /*
216 * List of command tables and list of line-edit tables.
217 */
218 static struct tablelist *list_fcmd_tables = NULL;
219 static struct tablelist *list_ecmd_tables = NULL;
220 static struct tablelist *list_var_tables = NULL;
221 static struct tablelist *list_sysvar_tables = NULL;
222
223
224 /*
225 * Expand special key abbreviations in a command table.
226 */
227 static void
expand_special_keys(table,len)228 expand_special_keys(table, len)
229 char *table;
230 int len;
231 {
232 register char *fm;
233 register char *to;
234 register int a;
235 char *repl;
236 int klen;
237
238 for (fm = table; fm < table + len; )
239 {
240 /*
241 * Rewrite each command in the table with any
242 * special key abbreviations expanded.
243 */
244 for (to = fm; *fm != '\0'; )
245 {
246 if (*fm != SK_SPECIAL_KEY)
247 {
248 *to++ = *fm++;
249 continue;
250 }
251 /*
252 * After SK_SPECIAL_KEY, next byte is the type
253 * of special key (one of the SK_* contants),
254 * and the byte after that is the number of bytes,
255 * N, reserved by the abbreviation (including the
256 * SK_SPECIAL_KEY and key type bytes).
257 * Replace all N bytes with the actual bytes
258 * output by the special key on this terminal.
259 */
260 repl = special_key_str(fm[1]);
261 klen = fm[2] & 0377;
262 fm += klen;
263 if (repl == NULL || (int) strlen(repl) > klen)
264 repl = "\377";
265 while (*repl != '\0')
266 *to++ = *repl++;
267 }
268 *to++ = '\0';
269 /*
270 * Fill any unused bytes between end of command and
271 * the action byte with A_SKIP.
272 */
273 while (to <= fm)
274 *to++ = A_SKIP;
275 fm++;
276 a = *fm++ & 0377;
277 if (a & A_EXTRA)
278 {
279 while (*fm++ != '\0')
280 continue;
281 }
282 }
283 }
284
285 /*
286 * Initialize the command lists.
287 */
288 public void
init_cmds()289 init_cmds()
290 {
291 /*
292 * Add the default command tables.
293 */
294 add_fcmd_table((char*)cmdtable, sizeof(cmdtable));
295 add_ecmd_table((char*)edittable, sizeof(edittable));
296 #if USERFILE
297 /*
298 * For backwards compatibility,
299 * try to add tables in the OLD system lesskey file.
300 */
301 #ifdef BINDIR
302 add_hometable(NULL, BINDIR "/.sysless", 1);
303 #endif
304 /*
305 * Try to add the tables in the system lesskey file.
306 */
307 add_hometable("LESSKEY_SYSTEM", LESSKEYFILE_SYS, 1);
308 /*
309 * Try to add the tables in the standard lesskey file "$HOME/.less".
310 */
311 add_hometable("LESSKEY", LESSKEYFILE, 0);
312 #endif
313 }
314
315 /*
316 * Add a command table.
317 */
318 static int
add_cmd_table(tlist,buf,len)319 add_cmd_table(tlist, buf, len)
320 struct tablelist **tlist;
321 char *buf;
322 int len;
323 {
324 register struct tablelist *t;
325
326 if (len == 0)
327 return (0);
328 /*
329 * Allocate a tablelist structure, initialize it,
330 * and link it into the list of tables.
331 */
332 if ((t = (struct tablelist *)
333 calloc(1, sizeof(struct tablelist))) == NULL)
334 {
335 return (-1);
336 }
337 expand_special_keys(buf, len);
338 t->t_start = buf;
339 t->t_end = buf + len;
340 t->t_next = *tlist;
341 *tlist = t;
342 return (0);
343 }
344
345 /*
346 * Add a command table.
347 */
348 public void
add_fcmd_table(buf,len)349 add_fcmd_table(buf, len)
350 char *buf;
351 int len;
352 {
353 if (add_cmd_table(&list_fcmd_tables, buf, len) < 0)
354 error("Warning: some commands disabled", NULL_PARG);
355 }
356
357 /*
358 * Add an editing command table.
359 */
360 public void
add_ecmd_table(buf,len)361 add_ecmd_table(buf, len)
362 char *buf;
363 int len;
364 {
365 if (add_cmd_table(&list_ecmd_tables, buf, len) < 0)
366 error("Warning: some edit commands disabled", NULL_PARG);
367 }
368
369 /*
370 * Add an environment variable table.
371 */
372 static void
add_var_table(tlist,buf,len)373 add_var_table(tlist, buf, len)
374 struct tablelist **tlist;
375 char *buf;
376 int len;
377 {
378 if (add_cmd_table(tlist, buf, len) < 0)
379 error("Warning: environment variables from lesskey file unavailable", NULL_PARG);
380 }
381
382 /*
383 * Search a single command table for the command string in cmd.
384 */
385 static int
cmd_search(cmd,table,endtable,sp)386 cmd_search(cmd, table, endtable, sp)
387 char *cmd;
388 char *table;
389 char *endtable;
390 char **sp;
391 {
392 register char *p;
393 register char *q;
394 register int a;
395
396 *sp = NULL;
397 for (p = table, q = cmd; p < endtable; p++, q++)
398 {
399 if (*p == *q)
400 {
401 /*
402 * Current characters match.
403 * If we're at the end of the string, we've found it.
404 * Return the action code, which is the character
405 * after the null at the end of the string
406 * in the command table.
407 */
408 if (*p == '\0')
409 {
410 a = *++p & 0377;
411 while (a == A_SKIP)
412 a = *++p & 0377;
413 if (a == A_END_LIST)
414 {
415 /*
416 * We get here only if the original
417 * cmd string passed in was empty ("").
418 * I don't think that can happen,
419 * but just in case ...
420 */
421 return (A_UINVALID);
422 }
423 /*
424 * Check for an "extra" string.
425 */
426 if (a & A_EXTRA)
427 {
428 *sp = ++p;
429 a &= ~A_EXTRA;
430 }
431 return (a);
432 }
433 } else if (*q == '\0')
434 {
435 /*
436 * Hit the end of the user's command,
437 * but not the end of the string in the command table.
438 * The user's command is incomplete.
439 */
440 return (A_PREFIX);
441 } else
442 {
443 /*
444 * Not a match.
445 * Skip ahead to the next command in the
446 * command table, and reset the pointer
447 * to the beginning of the user's command.
448 */
449 if (*p == '\0' && p[1] == A_END_LIST)
450 {
451 /*
452 * A_END_LIST is a special marker that tells
453 * us to abort the cmd search.
454 */
455 return (A_UINVALID);
456 }
457 while (*p++ != '\0')
458 continue;
459 while (*p == A_SKIP)
460 p++;
461 if (*p & A_EXTRA)
462 while (*++p != '\0')
463 continue;
464 q = cmd-1;
465 }
466 }
467 /*
468 * No match found in the entire command table.
469 */
470 return (A_INVALID);
471 }
472
473 /*
474 * Decode a command character and return the associated action.
475 * The "extra" string, if any, is returned in sp.
476 */
477 static int
cmd_decode(tlist,cmd,sp)478 cmd_decode(tlist, cmd, sp)
479 struct tablelist *tlist;
480 char *cmd;
481 char **sp;
482 {
483 register struct tablelist *t;
484 register int action = A_INVALID;
485
486 /*
487 * Search thru all the command tables.
488 * Stop when we find an action which is not A_INVALID.
489 */
490 for (t = tlist; t != NULL; t = t->t_next)
491 {
492 action = cmd_search(cmd, t->t_start, t->t_end, sp);
493 if (action != A_INVALID)
494 break;
495 }
496 if (action == A_UINVALID)
497 action = A_INVALID;
498 return (action);
499 }
500
501 /*
502 * Decode a command from the cmdtables list.
503 */
504 public int
fcmd_decode(cmd,sp)505 fcmd_decode(cmd, sp)
506 char *cmd;
507 char **sp;
508 {
509 return (cmd_decode(list_fcmd_tables, cmd, sp));
510 }
511
512 /*
513 * Decode a command from the edittables list.
514 */
515 public int
ecmd_decode(cmd,sp)516 ecmd_decode(cmd, sp)
517 char *cmd;
518 char **sp;
519 {
520 return (cmd_decode(list_ecmd_tables, cmd, sp));
521 }
522
523 /*
524 * Get the value of an environment variable.
525 * Looks first in the lesskey file, then in the real environment.
526 */
527 public char *
lgetenv(var)528 lgetenv(var)
529 char *var;
530 {
531 int a;
532 char *s;
533
534 a = cmd_decode(list_var_tables, var, &s);
535 if (a == EV_OK)
536 return (s);
537 s = getenv(var);
538 if (s != NULL && *s != '\0')
539 return (s);
540 a = cmd_decode(list_sysvar_tables, var, &s);
541 if (a == EV_OK)
542 return (s);
543 return (NULL);
544 }
545
546 #if USERFILE
547 /*
548 * Get an "integer" from a lesskey file.
549 * Integers are stored in a funny format:
550 * two bytes, low order first, in radix KRADIX.
551 */
552 static int
gint(sp)553 gint(sp)
554 char **sp;
555 {
556 int n;
557
558 n = *(*sp)++;
559 n += *(*sp)++ * KRADIX;
560 return (n);
561 }
562
563 /*
564 * Process an old (pre-v241) lesskey file.
565 */
566 static int
old_lesskey(buf,len)567 old_lesskey(buf, len)
568 char *buf;
569 int len;
570 {
571 /*
572 * Old-style lesskey file.
573 * The file must end with either
574 * ...,cmd,0,action
575 * or ...,cmd,0,action|A_EXTRA,string,0
576 * So the last byte or the second to last byte must be zero.
577 */
578 if (buf[len-1] != '\0' && buf[len-2] != '\0')
579 return (-1);
580 add_fcmd_table(buf, len);
581 return (0);
582 }
583
584 /*
585 * Process a new (post-v241) lesskey file.
586 */
587 static int
new_lesskey(buf,len,sysvar)588 new_lesskey(buf, len, sysvar)
589 char *buf;
590 int len;
591 int sysvar;
592 {
593 char *p;
594 register int c;
595 register int n;
596
597 /*
598 * New-style lesskey file.
599 * Extract the pieces.
600 */
601 if (buf[len-3] != C0_END_LESSKEY_MAGIC ||
602 buf[len-2] != C1_END_LESSKEY_MAGIC ||
603 buf[len-1] != C2_END_LESSKEY_MAGIC)
604 return (-1);
605 p = buf + 4;
606 for (;;)
607 {
608 c = *p++;
609 switch (c)
610 {
611 case CMD_SECTION:
612 n = gint(&p);
613 add_fcmd_table(p, n);
614 p += n;
615 break;
616 case EDIT_SECTION:
617 n = gint(&p);
618 add_ecmd_table(p, n);
619 p += n;
620 break;
621 case VAR_SECTION:
622 n = gint(&p);
623 add_var_table((sysvar) ?
624 &list_sysvar_tables : &list_var_tables, p, n);
625 p += n;
626 break;
627 case END_SECTION:
628 return (0);
629 default:
630 /*
631 * Unrecognized section type.
632 */
633 return (-1);
634 }
635 }
636 }
637
638 /*
639 * Set up a user command table, based on a "lesskey" file.
640 */
641 public int
lesskey(filename,sysvar)642 lesskey(filename, sysvar)
643 char *filename;
644 int sysvar;
645 {
646 register char *buf;
647 register POSITION len;
648 register long n;
649 register int f;
650
651 if (secure)
652 return (1);
653 /*
654 * Try to open the lesskey file.
655 */
656 filename = shell_unquote(filename);
657 f = open(filename, OPEN_READ);
658 free(filename);
659 if (f < 0)
660 return (1);
661
662 /*
663 * Read the file into a buffer.
664 * We first figure out the size of the file and allocate space for it.
665 * {{ Minimal error checking is done here.
666 * A garbage .less file will produce strange results.
667 * To avoid a large amount of error checking code here, we
668 * rely on the lesskey program to generate a good .less file. }}
669 */
670 len = filesize(f);
671 if (len == NULL_POSITION || len < 3)
672 {
673 /*
674 * Bad file (valid file must have at least 3 chars).
675 */
676 close(f);
677 return (-1);
678 }
679 if ((buf = (char *) calloc((int)len, sizeof(char))) == NULL)
680 {
681 close(f);
682 return (-1);
683 }
684 if (lseek(f, (off_t)0, 0) == BAD_LSEEK)
685 {
686 free(buf);
687 close(f);
688 return (-1);
689 }
690 n = read(f, buf, (unsigned int) len);
691 close(f);
692 if (n != len)
693 {
694 free(buf);
695 return (-1);
696 }
697
698 /*
699 * Figure out if this is an old-style (before version 241)
700 * or new-style lesskey file format.
701 */
702 if (buf[0] != C0_LESSKEY_MAGIC || buf[1] != C1_LESSKEY_MAGIC ||
703 buf[2] != C2_LESSKEY_MAGIC || buf[3] != C3_LESSKEY_MAGIC)
704 return (old_lesskey(buf, (int)len));
705 return (new_lesskey(buf, (int)len, sysvar));
706 }
707
708 /*
709 * Add the standard lesskey file "$HOME/.less"
710 */
711 public void
add_hometable(envname,def_filename,sysvar)712 add_hometable(envname, def_filename, sysvar)
713 char *envname;
714 char *def_filename;
715 int sysvar;
716 {
717 char *filename;
718 PARG parg;
719
720 if (envname != NULL && (filename = lgetenv(envname)) != NULL)
721 filename = save(filename);
722 else if (sysvar)
723 filename = save(def_filename);
724 else
725 filename = homefile(def_filename);
726 if (filename == NULL)
727 return;
728 if (lesskey(filename, sysvar) < 0)
729 {
730 parg.p_string = filename;
731 error("Cannot use lesskey file \"%s\"", &parg);
732 }
733 free(filename);
734 }
735 #endif
736
737 /*
738 * See if a char is a special line-editing command.
739 */
740 public int
editchar(c,flags)741 editchar(c, flags)
742 int c;
743 int flags;
744 {
745 int action;
746 int nch;
747 char *s;
748 char usercmd[MAX_CMDLEN+1];
749
750 /*
751 * An editing character could actually be a sequence of characters;
752 * for example, an escape sequence sent by pressing the uparrow key.
753 * To match the editing string, we use the command decoder
754 * but give it the edit-commands command table
755 * This table is constructed to match the user's keyboard.
756 */
757 if (c == erase_char)
758 return (EC_BACKSPACE);
759 if (c == kill_char)
760 return (EC_LINEKILL);
761
762 /*
763 * Collect characters in a buffer.
764 * Start with the one we have, and get more if we need them.
765 */
766 nch = 0;
767 do {
768 if (nch > 0)
769 c = getcc();
770 usercmd[nch] = c;
771 usercmd[nch+1] = '\0';
772 nch++;
773 action = ecmd_decode(usercmd, &s);
774 } while (action == A_PREFIX);
775
776 if (flags & EC_NORIGHTLEFT)
777 {
778 switch (action)
779 {
780 case EC_RIGHT:
781 case EC_LEFT:
782 action = A_INVALID;
783 break;
784 }
785 }
786 #if CMD_HISTORY
787 if (flags & EC_NOHISTORY)
788 {
789 /*
790 * The caller says there is no history list.
791 * Reject any history-manipulation action.
792 */
793 switch (action)
794 {
795 case EC_UP:
796 case EC_DOWN:
797 action = A_INVALID;
798 break;
799 }
800 }
801 #endif
802 #if TAB_COMPLETE_FILENAME
803 if (flags & EC_NOCOMPLETE)
804 {
805 /*
806 * The caller says we don't want any filename completion cmds.
807 * Reject them.
808 */
809 switch (action)
810 {
811 case EC_F_COMPLETE:
812 case EC_B_COMPLETE:
813 case EC_EXPAND:
814 action = A_INVALID;
815 break;
816 }
817 }
818 #endif
819 if ((flags & EC_PEEK) || action == A_INVALID)
820 {
821 /*
822 * We're just peeking, or we didn't understand the command.
823 * Unget all the characters we read in the loop above.
824 * This does NOT include the original character that was
825 * passed in as a parameter.
826 */
827 while (nch > 1)
828 {
829 ungetcc(usercmd[--nch]);
830 }
831 } else
832 {
833 if (s != NULL)
834 ungetsc(s);
835 }
836 return action;
837 }
838
839