1 /* $NetBSD: decode.c,v 1.4 2013/09/04 19:44:21 tron Exp $ */
2
3 /*
4 * Copyright (C) 1984-2012 Mark Nudelman
5 *
6 * You may distribute under the terms of either the GNU General Public
7 * License or the Less License, as specified in the README file.
8 *
9 * For more information, see the README file.
10 */
11
12
13 /*
14 * Routines to decode user commands.
15 *
16 * This is all table driven.
17 * A command table is a sequence of command descriptors.
18 * Each command descriptor is a sequence of bytes with the following format:
19 * <c1><c2>...<cN><0><action>
20 * The characters c1,c2,...,cN are the command string; that is,
21 * the characters which the user must type.
22 * It is terminated by a null <0> byte.
23 * The byte after the null byte is the action code associated
24 * with the command string.
25 * If an action byte is OR-ed with A_EXTRA, this indicates
26 * that the option byte is followed by an extra string.
27 *
28 * There may be many command tables.
29 * The first (default) table is built-in.
30 * Other tables are read in from "lesskey" files.
31 * All the tables are linked together and are searched in order.
32 */
33
34 #include "less.h"
35 #include "cmd.h"
36 #include "lesskey.h"
37
38 extern int erase_char, erase2_char, kill_char;
39 extern int secure;
40
41 #define SK(k) \
42 SK_SPECIAL_KEY, (k), 6, 1, 1, 1
43 /*
44 * Command table is ordered roughly according to expected
45 * frequency of use, so the common commands are near the beginning.
46 */
47
48 static unsigned char cmdtable[] =
49 {
50 '\r',0, A_F_LINE,
51 '\n',0, A_F_LINE,
52 'e',0, A_F_LINE,
53 'j',0, A_F_LINE,
54 SK(SK_DOWN_ARROW),0, A_F_LINE,
55 CONTROL('E'),0, A_F_LINE,
56 CONTROL('N'),0, A_F_LINE,
57 'k',0, A_B_LINE,
58 'y',0, A_B_LINE,
59 CONTROL('Y'),0, A_B_LINE,
60 SK(SK_CONTROL_K),0, A_B_LINE,
61 CONTROL('P'),0, A_B_LINE,
62 SK(SK_UP_ARROW),0, A_B_LINE,
63 'J',0, A_FF_LINE,
64 'K',0, A_BF_LINE,
65 'Y',0, A_BF_LINE,
66 'd',0, A_F_SCROLL,
67 CONTROL('D'),0, A_F_SCROLL,
68 'u',0, A_B_SCROLL,
69 CONTROL('U'),0, A_B_SCROLL,
70 ' ',0, A_F_SCREEN,
71 'f',0, A_F_SCREEN,
72 CONTROL('F'),0, A_F_SCREEN,
73 CONTROL('V'),0, A_F_SCREEN,
74 SK(SK_PAGE_DOWN),0, A_F_SCREEN,
75 'b',0, A_B_SCREEN,
76 CONTROL('B'),0, A_B_SCREEN,
77 ESC,'v',0, A_B_SCREEN,
78 SK(SK_PAGE_UP),0, A_B_SCREEN,
79 'z',0, A_F_WINDOW,
80 'w',0, A_B_WINDOW,
81 ESC,' ',0, A_FF_SCREEN,
82 'F',0, A_F_FOREVER,
83 ESC,'F',0, A_F_UNTIL_HILITE,
84 'R',0, A_FREPAINT,
85 'r',0, A_REPAINT,
86 CONTROL('R'),0, A_REPAINT,
87 CONTROL('L'),0, A_REPAINT,
88 ESC,'u',0, A_UNDO_SEARCH,
89 'g',0, A_GOLINE,
90 SK(SK_HOME),0, A_GOLINE,
91 '<',0, A_GOLINE,
92 ESC,'<',0, A_GOLINE,
93 'p',0, A_PERCENT,
94 '%',0, A_PERCENT,
95 ESC,'[',0, A_LSHIFT,
96 ESC,']',0, A_RSHIFT,
97 ESC,'(',0, A_LSHIFT,
98 ESC,')',0, A_RSHIFT,
99 SK(SK_RIGHT_ARROW),0, A_RSHIFT,
100 SK(SK_LEFT_ARROW),0, A_LSHIFT,
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 '[',0, A_F_BRACKET|A_EXTRA, '[',']',0,
106 ']',0, A_B_BRACKET|A_EXTRA, '[',']',0,
107 ESC,CONTROL('F'),0, A_F_BRACKET,
108 ESC,CONTROL('B'),0, A_B_BRACKET,
109 'G',0, A_GOEND,
110 ESC,'>',0, A_GOEND,
111 '>',0, A_GOEND,
112 SK(SK_END),0, A_GOEND,
113 'P',0, A_GOPOS,
114
115 '0',0, A_DIGIT,
116 '1',0, A_DIGIT,
117 '2',0, A_DIGIT,
118 '3',0, A_DIGIT,
119 '4',0, A_DIGIT,
120 '5',0, A_DIGIT,
121 '6',0, A_DIGIT,
122 '7',0, A_DIGIT,
123 '8',0, A_DIGIT,
124 '9',0, A_DIGIT,
125 '.',0, A_DIGIT,
126
127 '=',0, A_STAT,
128 CONTROL('G'),0, A_STAT,
129 ':','f',0, A_STAT,
130 '/',0, A_F_SEARCH,
131 '?',0, A_B_SEARCH,
132 ESC,'/',0, A_F_SEARCH|A_EXTRA, '*',0,
133 ESC,'?',0, A_B_SEARCH|A_EXTRA, '*',0,
134 'n',0, A_AGAIN_SEARCH,
135 ESC,'n',0, A_T_AGAIN_SEARCH,
136 'N',0, A_REVERSE_SEARCH,
137 ESC,'N',0, A_T_REVERSE_SEARCH,
138 '&',0, A_FILTER,
139 'm',0, A_SETMARK,
140 '\'',0, A_GOMARK,
141 CONTROL('X'),CONTROL('X'),0, A_GOMARK,
142 'E',0, A_EXAMINE,
143 ':','e',0, A_EXAMINE,
144 CONTROL('X'),CONTROL('V'),0, A_EXAMINE,
145 ':','n',0, A_NEXT_FILE,
146 ':','p',0, A_PREV_FILE,
147 't',0, A_NEXT_TAG,
148 'T',0, A_PREV_TAG,
149 ':','x',0, A_INDEX_FILE,
150 ':','d',0, A_REMOVE_FILE,
151 '-',0, A_OPT_TOGGLE,
152 ':','t',0, A_OPT_TOGGLE|A_EXTRA, 't',0,
153 's',0, A_OPT_TOGGLE|A_EXTRA, 'o',0,
154 '_',0, A_DISP_OPTION,
155 '|',0, A_PIPE,
156 'v',0, A_VISUAL,
157 '!',0, A_SHELL,
158 '+',0, A_FIRSTCMD,
159
160 'H',0, A_HELP,
161 'h',0, A_HELP,
162 SK(SK_F1),0, A_HELP,
163 'V',0, A_VERSION,
164 'q',0, A_QUIT,
165 'Q',0, A_QUIT,
166 ':','q',0, A_QUIT,
167 ':','Q',0, A_QUIT,
168 'Z','Z',0, A_QUIT
169 };
170
171 static unsigned char edittable[] =
172 {
173 '\t',0, EC_F_COMPLETE, /* TAB */
174 '\17',0, EC_B_COMPLETE, /* BACKTAB */
175 SK(SK_BACKTAB),0, EC_B_COMPLETE, /* BACKTAB */
176 ESC,'\t',0, EC_B_COMPLETE, /* ESC TAB */
177 CONTROL('L'),0, EC_EXPAND, /* CTRL-L */
178 CONTROL('V'),0, EC_LITERAL, /* BACKSLASH */
179 CONTROL('A'),0, EC_LITERAL, /* BACKSLASH */
180 ESC,'l',0, EC_RIGHT, /* ESC l */
181 SK(SK_RIGHT_ARROW),0, EC_RIGHT, /* RIGHTARROW */
182 ESC,'h',0, EC_LEFT, /* ESC h */
183 SK(SK_LEFT_ARROW),0, EC_LEFT, /* LEFTARROW */
184 ESC,'b',0, EC_W_LEFT, /* ESC b */
185 ESC,SK(SK_LEFT_ARROW),0, EC_W_LEFT, /* ESC LEFTARROW */
186 SK(SK_CTL_LEFT_ARROW),0, EC_W_LEFT, /* CTRL-LEFTARROW */
187 ESC,'w',0, EC_W_RIGHT, /* ESC w */
188 ESC,SK(SK_RIGHT_ARROW),0, EC_W_RIGHT, /* ESC RIGHTARROW */
189 SK(SK_CTL_RIGHT_ARROW),0, EC_W_RIGHT, /* CTRL-RIGHTARROW */
190 ESC,'i',0, EC_INSERT, /* ESC i */
191 SK(SK_INSERT),0, EC_INSERT, /* INSERT */
192 ESC,'x',0, EC_DELETE, /* ESC x */
193 SK(SK_DELETE),0, EC_DELETE, /* DELETE */
194 ESC,'X',0, EC_W_DELETE, /* ESC X */
195 ESC,SK(SK_DELETE),0, EC_W_DELETE, /* ESC DELETE */
196 SK(SK_CTL_DELETE),0, EC_W_DELETE, /* CTRL-DELETE */
197 SK(SK_CTL_BACKSPACE),0, EC_W_BACKSPACE, /* CTRL-BACKSPACE */
198 ESC,'\b',0, EC_W_BACKSPACE, /* ESC BACKSPACE */
199 ESC,'0',0, EC_HOME, /* ESC 0 */
200 SK(SK_HOME),0, EC_HOME, /* HOME */
201 ESC,'$',0, EC_END, /* ESC $ */
202 SK(SK_END),0, EC_END, /* END */
203 ESC,'k',0, EC_UP, /* ESC k */
204 SK(SK_UP_ARROW),0, EC_UP, /* UPARROW */
205 ESC,'j',0, EC_DOWN, /* ESC j */
206 SK(SK_DOWN_ARROW),0, EC_DOWN, /* DOWNARROW */
207 CONTROL('G'),0, EC_ABORT, /* CTRL-G */
208 };
209
210 /*
211 * Structure to support a list of command tables.
212 */
213 struct tablelist
214 {
215 struct tablelist *t_next;
216 char *t_start;
217 char *t_end;
218 };
219
220 /*
221 * List of command tables and list of line-edit tables.
222 */
223 static struct tablelist *list_fcmd_tables = NULL;
224 static struct tablelist *list_ecmd_tables = NULL;
225 static struct tablelist *list_var_tables = NULL;
226 static struct tablelist *list_sysvar_tables = NULL;
227
228 static int add_cmd_table __P((struct tablelist **, char *, int));
229 static int cmd_decode __P((struct tablelist *, char *, char **));
230 static int gint __P((char **));
231 static int old_lesskey __P((char *, int));
232 static int new_lesskey __P((char *, int, int));
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 register char *fm;
243 register char *to;
244 register 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 * Initialize the command lists.
297 */
298 public void
init_cmds()299 init_cmds()
300 {
301 /*
302 * Add the default command tables.
303 */
304 add_fcmd_table((char*)cmdtable, sizeof(cmdtable));
305 add_ecmd_table((char*)edittable, sizeof(edittable));
306 #if USERFILE
307 /*
308 * For backwards compatibility,
309 * try to add tables in the OLD system lesskey file.
310 */
311 #ifdef BINDIR
312 add_hometable(NULL, BINDIR "/.sysless", 1);
313 #endif
314 /*
315 * Try to add the tables in the system lesskey file.
316 */
317 add_hometable("LESSKEY_SYSTEM", LESSKEYFILE_SYS, 1);
318 /*
319 * Try to add the tables in the standard lesskey file "$HOME/.less".
320 */
321 add_hometable("LESSKEY", LESSKEYFILE, 0);
322 #endif
323 }
324
325 /*
326 * Add a command table.
327 */
328 static int
add_cmd_table(tlist,buf,len)329 add_cmd_table(tlist, buf, len)
330 struct tablelist **tlist;
331 char *buf;
332 int len;
333 {
334 register struct tablelist *t;
335
336 if (len == 0)
337 return (0);
338 /*
339 * Allocate a tablelist structure, initialize it,
340 * and link it into the list of tables.
341 */
342 if ((t = (struct tablelist *)
343 calloc(1, sizeof(struct tablelist))) == NULL)
344 {
345 return (-1);
346 }
347 expand_special_keys(buf, len);
348 t->t_start = buf;
349 t->t_end = buf + len;
350 t->t_next = *tlist;
351 *tlist = t;
352 return (0);
353 }
354
355 /*
356 * Add a command table.
357 */
358 public void
add_fcmd_table(buf,len)359 add_fcmd_table(buf, len)
360 char *buf;
361 int len;
362 {
363 if (add_cmd_table(&list_fcmd_tables, buf, len) < 0)
364 error("Warning: some commands disabled", NULL_PARG);
365 }
366
367 /*
368 * Add an editing command table.
369 */
370 public void
add_ecmd_table(buf,len)371 add_ecmd_table(buf, len)
372 char *buf;
373 int len;
374 {
375 if (add_cmd_table(&list_ecmd_tables, buf, len) < 0)
376 error("Warning: some edit commands disabled", NULL_PARG);
377 }
378
379 /*
380 * Add an environment variable table.
381 */
382 static void
add_var_table(tlist,buf,len)383 add_var_table(tlist, buf, len)
384 struct tablelist **tlist;
385 char *buf;
386 int len;
387 {
388 if (add_cmd_table(tlist, buf, len) < 0)
389 error("Warning: environment variables from lesskey file unavailable", NULL_PARG);
390 }
391
392 /*
393 * Search a single command table for the command string in cmd.
394 */
395 static int
cmd_search(cmd,table,endtable,sp)396 cmd_search(cmd, table, endtable, sp)
397 char *cmd;
398 char *table;
399 char *endtable;
400 char **sp;
401 {
402 register char *p;
403 register char *q;
404 register int a;
405
406 *sp = NULL;
407 for (p = table, q = cmd; p < endtable; p++, q++)
408 {
409 if (*p == *q)
410 {
411 /*
412 * Current characters match.
413 * If we're at the end of the string, we've found it.
414 * Return the action code, which is the character
415 * after the null at the end of the string
416 * in the command table.
417 */
418 if (*p == '\0')
419 {
420 a = *++p & 0377;
421 while (a == A_SKIP)
422 a = *++p & 0377;
423 if (a == A_END_LIST)
424 {
425 /*
426 * We get here only if the original
427 * cmd string passed in was empty ("").
428 * I don't think that can happen,
429 * but just in case ...
430 */
431 return (A_UINVALID);
432 }
433 /*
434 * Check for an "extra" string.
435 */
436 if (a & A_EXTRA)
437 {
438 *sp = ++p;
439 a &= ~A_EXTRA;
440 }
441 return (a);
442 }
443 } else if (*q == '\0')
444 {
445 /*
446 * Hit the end of the user's command,
447 * but not the end of the string in the command table.
448 * The user's command is incomplete.
449 */
450 return (A_PREFIX);
451 } else
452 {
453 /*
454 * Not a match.
455 * Skip ahead to the next command in the
456 * command table, and reset the pointer
457 * to the beginning of the user's command.
458 */
459 if (*p == '\0' && p[1] == A_END_LIST)
460 {
461 /*
462 * A_END_LIST is a special marker that tells
463 * us to abort the cmd search.
464 */
465 return (A_UINVALID);
466 }
467 while (*p++ != '\0')
468 continue;
469 while (*p == A_SKIP)
470 p++;
471 if (*p & A_EXTRA)
472 while (*++p != '\0')
473 continue;
474 q = cmd-1;
475 }
476 }
477 /*
478 * No match found in the entire command table.
479 */
480 return (A_INVALID);
481 }
482
483 /*
484 * Decode a command character and return the associated action.
485 * The "extra" string, if any, is returned in sp.
486 */
487 static int
cmd_decode(tlist,cmd,sp)488 cmd_decode(tlist, cmd, sp)
489 struct tablelist *tlist;
490 char *cmd;
491 char **sp;
492 {
493 register struct tablelist *t;
494 register int action = A_INVALID;
495
496 /*
497 * Search thru all the command tables.
498 * Stop when we find an action which is not A_INVALID.
499 */
500 for (t = tlist; t != NULL; t = t->t_next)
501 {
502 action = cmd_search(cmd, t->t_start, t->t_end, sp);
503 if (action != A_INVALID)
504 break;
505 }
506 if (action == A_UINVALID)
507 action = A_INVALID;
508 return (action);
509 }
510
511 /*
512 * Decode a command from the cmdtables list.
513 */
514 public int
fcmd_decode(cmd,sp)515 fcmd_decode(cmd, sp)
516 char *cmd;
517 char **sp;
518 {
519 return (cmd_decode(list_fcmd_tables, cmd, sp));
520 }
521
522 /*
523 * Decode a command from the edittables list.
524 */
525 public int
ecmd_decode(cmd,sp)526 ecmd_decode(cmd, sp)
527 char *cmd;
528 char **sp;
529 {
530 return (cmd_decode(list_ecmd_tables, cmd, sp));
531 }
532
533 /*
534 * Get the value of an environment variable.
535 * Looks first in the lesskey file, then in the real environment.
536 */
537 public char *
lgetenv(var)538 lgetenv(var)
539 char *var;
540 {
541 int a;
542 char *s;
543
544 a = cmd_decode(list_var_tables, var, &s);
545 if (a == EV_OK)
546 return (s);
547 s = getenv(var);
548 if (s != NULL && *s != '\0')
549 return (s);
550 a = cmd_decode(list_sysvar_tables, var, &s);
551 if (a == EV_OK)
552 return (s);
553 return (NULL);
554 }
555
556 #if USERFILE
557 /*
558 * Get an "integer" from a lesskey file.
559 * Integers are stored in a funny format:
560 * two bytes, low order first, in radix KRADIX.
561 */
562 static int
gint(sp)563 gint(sp)
564 char **sp;
565 {
566 int n;
567
568 n = *(*sp)++;
569 n += *(*sp)++ * KRADIX;
570 return (n);
571 }
572
573 /*
574 * Process an old (pre-v241) lesskey file.
575 */
576 static int
old_lesskey(buf,len)577 old_lesskey(buf, len)
578 char *buf;
579 int len;
580 {
581 /*
582 * Old-style lesskey file.
583 * The file must end with either
584 * ...,cmd,0,action
585 * or ...,cmd,0,action|A_EXTRA,string,0
586 * So the last byte or the second to last byte must be zero.
587 */
588 if (buf[len-1] != '\0' && buf[len-2] != '\0')
589 return (-1);
590 add_fcmd_table(buf, len);
591 return (0);
592 }
593
594 /*
595 * Process a new (post-v241) lesskey file.
596 */
597 static int
new_lesskey(buf,len,sysvar)598 new_lesskey(buf, len, sysvar)
599 char *buf;
600 int len;
601 int sysvar;
602 {
603 char *p;
604 register int c;
605 register int n;
606
607 /*
608 * New-style lesskey file.
609 * Extract the pieces.
610 */
611 if (buf[len-3] != C0_END_LESSKEY_MAGIC ||
612 buf[len-2] != C1_END_LESSKEY_MAGIC ||
613 buf[len-1] != C2_END_LESSKEY_MAGIC)
614 return (-1);
615 p = buf + 4;
616 for (;;)
617 {
618 c = *p++;
619 switch (c)
620 {
621 case CMD_SECTION:
622 n = gint(&p);
623 add_fcmd_table(p, n);
624 p += n;
625 break;
626 case EDIT_SECTION:
627 n = gint(&p);
628 add_ecmd_table(p, n);
629 p += n;
630 break;
631 case VAR_SECTION:
632 n = gint(&p);
633 add_var_table((sysvar) ?
634 &list_sysvar_tables : &list_var_tables, p, n);
635 p += n;
636 break;
637 case END_SECTION:
638 return (0);
639 default:
640 /*
641 * Unrecognized section type.
642 */
643 return (-1);
644 }
645 }
646 }
647
648 /*
649 * Set up a user command table, based on a "lesskey" file.
650 */
651 public int
lesskey(filename,sysvar)652 lesskey(filename, sysvar)
653 char *filename;
654 int sysvar;
655 {
656 register char *buf;
657 register POSITION len;
658 register long n;
659 register int f;
660
661 if (secure)
662 return (1);
663 /*
664 * Try to open the lesskey file.
665 */
666 filename = shell_unquote(filename);
667 f = open(filename, OPEN_READ);
668 free(filename);
669 if (f < 0)
670 return (1);
671
672 /*
673 * Read the file into a buffer.
674 * We first figure out the size of the file and allocate space for it.
675 * {{ Minimal error checking is done here.
676 * A garbage .less file will produce strange results.
677 * To avoid a large amount of error checking code here, we
678 * rely on the lesskey program to generate a good .less file. }}
679 */
680 len = filesize(f);
681 if (len == NULL_POSITION || len < 3)
682 {
683 /*
684 * Bad file (valid file must have at least 3 chars).
685 */
686 close(f);
687 return (-1);
688 }
689 if ((buf = (char *) calloc((int)len, sizeof(char))) == NULL)
690 {
691 close(f);
692 return (-1);
693 }
694 if (lseek(f, (off_t)0, SEEK_SET) == BAD_LSEEK)
695 {
696 free(buf);
697 close(f);
698 return (-1);
699 }
700 n = read(f, buf, (unsigned int) len);
701 close(f);
702 if (n != len)
703 {
704 free(buf);
705 return (-1);
706 }
707
708 /*
709 * Figure out if this is an old-style (before version 241)
710 * or new-style lesskey file format.
711 */
712 if (buf[0] != C0_LESSKEY_MAGIC || buf[1] != C1_LESSKEY_MAGIC ||
713 buf[2] != C2_LESSKEY_MAGIC || buf[3] != C3_LESSKEY_MAGIC)
714 return (old_lesskey(buf, (int)len));
715 return (new_lesskey(buf, (int)len, sysvar));
716 }
717
718 /*
719 * Add the standard lesskey file "$HOME/.less"
720 */
721 public void
add_hometable(envname,def_filename,sysvar)722 add_hometable(envname, def_filename, sysvar)
723 char *envname;
724 char *def_filename;
725 int sysvar;
726 {
727 char *filename;
728 PARG parg;
729
730 if (envname != NULL && (filename = lgetenv(envname)) != NULL)
731 filename = save(filename);
732 else if (sysvar)
733 filename = save(def_filename);
734 else
735 filename = homefile(def_filename);
736 if (filename == NULL)
737 return;
738 if (lesskey(filename, sysvar) < 0)
739 {
740 parg.p_string = filename;
741 error("Cannot use lesskey file \"%s\"", &parg);
742 }
743 free(filename);
744 }
745 #endif
746
747 /*
748 * See if a char is a special line-editing command.
749 */
750 public int
editchar(c,flags)751 editchar(c, flags)
752 int c;
753 int flags;
754 {
755 int action;
756 int nch;
757 char *s = NULL; /* XXX: GCC */
758 char usercmd[MAX_CMDLEN+1];
759
760 /*
761 * An editing character could actually be a sequence of characters;
762 * for example, an escape sequence sent by pressing the uparrow key.
763 * To match the editing string, we use the command decoder
764 * but give it the edit-commands command table
765 * This table is constructed to match the user's keyboard.
766 */
767 if (c == erase_char || c == erase2_char)
768 return (EC_BACKSPACE);
769 if (c == kill_char)
770 return (EC_LINEKILL);
771
772 /*
773 * Collect characters in a buffer.
774 * Start with the one we have, and get more if we need them.
775 */
776 nch = 0;
777 do {
778 if (nch > 0)
779 c = getcc();
780 usercmd[nch] = c;
781 usercmd[nch+1] = '\0';
782 nch++;
783 action = ecmd_decode(usercmd, &s);
784 } while (action == A_PREFIX);
785
786 if (flags & EC_NORIGHTLEFT)
787 {
788 switch (action)
789 {
790 case EC_RIGHT:
791 case EC_LEFT:
792 action = A_INVALID;
793 break;
794 }
795 }
796 #if CMD_HISTORY
797 if (flags & EC_NOHISTORY)
798 {
799 /*
800 * The caller says there is no history list.
801 * Reject any history-manipulation action.
802 */
803 switch (action)
804 {
805 case EC_UP:
806 case EC_DOWN:
807 action = A_INVALID;
808 break;
809 }
810 }
811 #endif
812 #if TAB_COMPLETE_FILENAME
813 if (flags & EC_NOCOMPLETE)
814 {
815 /*
816 * The caller says we don't want any filename completion cmds.
817 * Reject them.
818 */
819 switch (action)
820 {
821 case EC_F_COMPLETE:
822 case EC_B_COMPLETE:
823 case EC_EXPAND:
824 action = A_INVALID;
825 break;
826 }
827 }
828 #endif
829 if ((flags & EC_PEEK) || action == A_INVALID)
830 {
831 /*
832 * We're just peeking, or we didn't understand the command.
833 * Unget all the characters we read in the loop above.
834 * This does NOT include the original character that was
835 * passed in as a parameter.
836 */
837 while (nch > 1)
838 {
839 ungetcc(usercmd[--nch]);
840 }
841 } else
842 {
843 if (s != NULL)
844 ungetsc(s);
845 }
846 return action;
847 }
848
849