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
36extern int erase_char, erase2_char, kill_char;
37extern 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
46static 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
176static 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 */
218struct 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 */
228static struct tablelist *list_fcmd_tables = NULL;
229static struct tablelist *list_ecmd_tables = NULL;
230static struct tablelist *list_var_tables = NULL;
231static struct tablelist *list_sysvar_tables = NULL;
232
233
234/*
235 * Expand special key abbreviations in a command table.
236 */
237	static void
238expand_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
299expand_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
313expand_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
326init_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
356add_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
385add_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
397add_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
409add_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
422cmd_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
514cmd_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
541fcmd_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
552ecmd_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 *
564lgetenv(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
589gint(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
603old_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
624new_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
678lesskey(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
746add_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
775editchar(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