xref: /freebsd/contrib/less/opttbl.c (revision dd41de95a84d979615a2ef11df6850622bf6184e)
1 /*
2  * Copyright (C) 1984-2021  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  * The option table.
13  */
14 
15 #include "less.h"
16 #include "option.h"
17 
18 /*
19  * Variables controlled by command line options.
20  */
21 public int quiet;               /* Should we suppress the audible bell? */
22 public int how_search;          /* Where should forward searches start? */
23 public int top_scroll;          /* Repaint screen from top?
24                                    (alternative is scroll from bottom) */
25 public int pr_type;             /* Type of prompt (short, medium, long) */
26 public int bs_mode;             /* How to process backspaces */
27 public int know_dumb;           /* Don't complain about dumb terminals */
28 public int quit_at_eof;         /* Quit after hitting end of file twice */
29 public int quit_if_one_screen;  /* Quit if EOF on first screen */
30 public int squeeze;             /* Squeeze multiple blank lines into one */
31 public int tabstop;             /* Tab settings */
32 public int back_scroll;         /* Repaint screen on backwards movement */
33 public int forw_scroll;         /* Repaint screen on forward movement */
34 public int caseless;            /* Do "caseless" searches */
35 public int linenums;            /* Use line numbers */
36 public int autobuf;             /* Automatically allocate buffers as needed */
37 public int bufspace;            /* Max buffer space per file (K) */
38 public int ctldisp;             /* Send control chars to screen untranslated */
39 public int force_open;          /* Open the file even if not regular file */
40 public int swindow;             /* Size of scrolling window */
41 public int jump_sline;          /* Screen line of "jump target" */
42 public long jump_sline_fraction = -1;
43 public long shift_count_fraction = -1;
44 public int chopline;            /* Truncate displayed lines at screen width */
45 public int no_init;             /* Disable sending ti/te termcap strings */
46 public int no_keypad;           /* Disable sending ks/ke termcap strings */
47 public int twiddle;             /* Show tildes after EOF */
48 public int show_attn;           /* Hilite first unread line */
49 public int shift_count;         /* Number of positions to shift horizontally */
50 public int status_col;          /* Display a status column */
51 public int use_lessopen;        /* Use the LESSOPEN filter */
52 public int quit_on_intr;        /* Quit on interrupt */
53 public int follow_mode;         /* F cmd Follows file desc or file name? */
54 public int oldbot;              /* Old bottom of screen behavior {{REMOVE}} */
55 public int opt_use_backslash;   /* Use backslash escaping in option parsing */
56 public char rscroll_char;       /* Char which marks chopped lines with -S */
57 public int rscroll_attr;        /* Attribute of rscroll_char */
58 public int no_hist_dups;        /* Remove dups from history list */
59 public int mousecap;            /* Allow mouse for scrolling */
60 public int wheel_lines;         /* Number of lines to scroll on mouse wheel scroll */
61 public int perma_marks;         /* Save marks in history file */
62 public int linenum_width;       /* Width of line numbers */
63 public int status_col_width;    /* Width of status column */
64 public int incr_search;         /* Incremental search */
65 public int use_color;           /* Use UI color */
66 #if HILITE_SEARCH
67 public int hilite_search;       /* Highlight matched search patterns? */
68 #endif
69 
70 public int less_is_more = 0;    /* Make compatible with POSIX more */
71 
72 /*
73  * Long option names.
74  */
75 static struct optname a_optname      = { "search-skip-screen",   NULL };
76 static struct optname b_optname      = { "buffers",              NULL };
77 static struct optname B__optname     = { "auto-buffers",         NULL };
78 static struct optname c_optname      = { "clear-screen",         NULL };
79 static struct optname d_optname      = { "dumb",                 NULL };
80 static struct optname D__optname     = { "color",                NULL };
81 static struct optname e_optname      = { "quit-at-eof",          NULL };
82 static struct optname f_optname      = { "force",                NULL };
83 static struct optname F__optname     = { "quit-if-one-screen",   NULL };
84 #if HILITE_SEARCH
85 static struct optname g_optname      = { "hilite-search",        NULL };
86 #endif
87 static struct optname h_optname      = { "max-back-scroll",      NULL };
88 static struct optname i_optname      = { "ignore-case",          NULL };
89 static struct optname j_optname      = { "jump-target",          NULL };
90 static struct optname J__optname     = { "status-column",        NULL };
91 #if USERFILE
92 static struct optname k_optname      = { "lesskey-file",         NULL };
93 #endif
94 static struct optname K__optname     = { "quit-on-intr",         NULL };
95 static struct optname L__optname     = { "no-lessopen",          NULL };
96 static struct optname m_optname      = { "long-prompt",          NULL };
97 static struct optname n_optname      = { "line-numbers",         NULL };
98 #if LOGFILE
99 static struct optname o_optname      = { "log-file",             NULL };
100 static struct optname O__optname     = { "LOG-FILE",             NULL };
101 #endif
102 static struct optname p_optname      = { "pattern",              NULL };
103 static struct optname P__optname     = { "prompt",               NULL };
104 static struct optname q2_optname     = { "silent",               NULL };
105 static struct optname q_optname      = { "quiet",                &q2_optname };
106 static struct optname r_optname      = { "raw-control-chars",    NULL };
107 static struct optname s_optname      = { "squeeze-blank-lines",  NULL };
108 static struct optname S__optname     = { "chop-long-lines",      NULL };
109 #if TAGS
110 static struct optname t_optname      = { "tag",                  NULL };
111 static struct optname T__optname     = { "tag-file",             NULL };
112 #endif
113 static struct optname u_optname      = { "underline-special",    NULL };
114 static struct optname V__optname     = { "version",              NULL };
115 static struct optname w_optname      = { "hilite-unread",        NULL };
116 static struct optname x_optname      = { "tabs",                 NULL };
117 static struct optname X__optname     = { "no-init",              NULL };
118 static struct optname y_optname      = { "max-forw-scroll",      NULL };
119 static struct optname z_optname      = { "window",               NULL };
120 static struct optname quote_optname  = { "quotes",               NULL };
121 static struct optname tilde_optname  = { "tilde",                NULL };
122 static struct optname query_optname  = { "help",                 NULL };
123 static struct optname pound_optname  = { "shift",                NULL };
124 static struct optname keypad_optname = { "no-keypad",            NULL };
125 static struct optname oldbot_optname = { "old-bot",              NULL };
126 static struct optname follow_optname = { "follow-name",          NULL };
127 static struct optname use_backslash_optname = { "use-backslash", NULL };
128 static struct optname rscroll_optname = { "rscroll", NULL };
129 static struct optname nohistdups_optname = { "no-histdups",      NULL };
130 static struct optname mousecap_optname = { "mouse",              NULL };
131 static struct optname wheel_lines_optname = { "wheel-lines",     NULL };
132 static struct optname perma_marks_optname = { "save-marks",      NULL };
133 static struct optname linenum_width_optname = { "line-num-width", NULL };
134 static struct optname status_col_width_optname = { "status-col-width", NULL };
135 static struct optname incr_search_optname = { "incsearch",       NULL };
136 static struct optname use_color_optname = { "use-color",         NULL };
137 #if LESSTEST
138 static struct optname ttyin_name_optname = { "tty",              NULL };
139 static struct optname rstat_optname  = { "rstat",                NULL };
140 #endif /*LESSTEST*/
141 
142 
143 /*
144  * Table of all options and their semantics.
145  *
146  * For BOOL and TRIPLE options, odesc[0], odesc[1], odesc[2] are
147  * the description of the option when set to 0, 1 or 2, respectively.
148  * For NUMBER options, odesc[0] is the prompt to use when entering
149  * a new value, and odesc[1] is the description, which should contain
150  * one %d which is replaced by the value of the number.
151  * For STRING options, odesc[0] is the prompt to use when entering
152  * a new value, and odesc[1], if not NULL, is the set of characters
153  * that are valid in the string.
154  */
155 static struct loption option[] =
156 {
157 	{ 'a', &a_optname,
158 		TRIPLE, OPT_ONPLUS, &how_search, NULL,
159 		{
160 			"Search includes displayed screen",
161 			"Search skips displayed screen",
162 			"Search includes all of displayed screen"
163 		}
164 	},
165 
166 	{ 'b', &b_optname,
167 		NUMBER|INIT_HANDLER, 64, &bufspace, opt_b,
168 		{
169 			"Max buffer space per file (K): ",
170 			"Max buffer space per file: %dK",
171 			NULL
172 		}
173 	},
174 	{ 'B', &B__optname,
175 		BOOL, OPT_ON, &autobuf, NULL,
176 		{
177 			"Don't automatically allocate buffers",
178 			"Automatically allocate buffers when needed",
179 			NULL
180 		}
181 	},
182 	{ 'c', &c_optname,
183 		TRIPLE, OPT_OFF, &top_scroll, NULL,
184 		{
185 			"Repaint by scrolling from bottom of screen",
186 			"Repaint by painting from top of screen",
187 			"Repaint by painting from top of screen"
188 		}
189 	},
190 	{ 'd', &d_optname,
191 		BOOL|NO_TOGGLE, OPT_OFF, &know_dumb, NULL,
192 		{
193 			"Assume intelligent terminal",
194 			"Assume dumb terminal",
195 			NULL
196 		}
197 	},
198 	{ 'D', &D__optname,
199 		STRING|REPAINT|NO_QUERY, 0, NULL, opt_D,
200 		{
201 			"color desc: ",
202 			NULL,
203 			NULL
204 		}
205 	},
206 	{ 'e', &e_optname,
207 		TRIPLE, OPT_OFF, &quit_at_eof, NULL,
208 		{
209 			"Don't quit at end-of-file",
210 			"Quit at end-of-file",
211 			"Quit immediately at end-of-file"
212 		}
213 	},
214 	{ 'f', &f_optname,
215 		BOOL, OPT_OFF, &force_open, NULL,
216 		{
217 			"Open only regular files",
218 			"Open even non-regular files",
219 			NULL
220 		}
221 	},
222 	{ 'F', &F__optname,
223 		BOOL, OPT_OFF, &quit_if_one_screen, NULL,
224 		{
225 			"Don't quit if end-of-file on first screen",
226 			"Quit if end-of-file on first screen",
227 			NULL
228 		}
229 	},
230 #if HILITE_SEARCH
231 	{ 'g', &g_optname,
232 		TRIPLE|HL_REPAINT, OPT_ONPLUS, &hilite_search, NULL,
233 		{
234 			"Don't highlight search matches",
235 			"Highlight matches for previous search only",
236 			"Highlight all matches for previous search pattern",
237 		}
238 	},
239 #endif
240 	{ 'h', &h_optname,
241 		NUMBER, -1, &back_scroll, NULL,
242 		{
243 			"Backwards scroll limit: ",
244 			"Backwards scroll limit is %d lines",
245 			NULL
246 		}
247 	},
248 	{ 'i', &i_optname,
249 		TRIPLE|HL_REPAINT, OPT_OFF, &caseless, opt_i,
250 		{
251 			"Case is significant in searches",
252 			"Ignore case in searches",
253 			"Ignore case in searches and in patterns"
254 		}
255 	},
256 	{ 'j', &j_optname,
257 		STRING, 0, NULL, opt_j,
258 		{
259 			"Target line: ",
260 			"0123456789.-",
261 			NULL
262 		}
263 	},
264 	{ 'J', &J__optname,
265 		BOOL|REPAINT, OPT_OFF, &status_col, NULL,
266 		{
267 			"Don't display a status column",
268 			"Display a status column",
269 			NULL
270 		}
271 	},
272 #if USERFILE
273 	{ 'k', &k_optname,
274 		STRING|NO_TOGGLE|NO_QUERY, 0, NULL, opt_k,
275 		{ NULL, NULL, NULL }
276 	},
277 #endif
278 	{ 'K', &K__optname,
279 		BOOL, OPT_OFF, &quit_on_intr, NULL,
280 		{
281 			"Interrupt (ctrl-C) returns to prompt",
282 			"Interrupt (ctrl-C) exits less",
283 			NULL
284 		}
285 	},
286 	{ 'L', &L__optname,
287 		BOOL, OPT_ON, &use_lessopen, NULL,
288 		{
289 			"Don't use the LESSOPEN filter",
290 			"Use the LESSOPEN filter",
291 			NULL
292 		}
293 	},
294 	{ 'm', &m_optname,
295 		TRIPLE, OPT_OFF, &pr_type, NULL,
296 		{
297 			"Short prompt",
298 			"Medium prompt",
299 			"Long prompt"
300 		}
301 	},
302 	{ 'n', &n_optname,
303 		TRIPLE|REPAINT, OPT_ON, &linenums, NULL,
304 		{
305 			"Don't use line numbers",
306 			"Use line numbers",
307 			"Constantly display line numbers"
308 		}
309 	},
310 #if LOGFILE
311 	{ 'o', &o_optname,
312 		STRING, 0, NULL, opt_o,
313 		{ "log file: ", NULL, NULL }
314 	},
315 	{ 'O', &O__optname,
316 		STRING, 0, NULL, opt__O,
317 		{ "Log file: ", NULL, NULL }
318 	},
319 #endif
320 	{ 'p', &p_optname,
321 		STRING|NO_TOGGLE|NO_QUERY, 0, NULL, opt_p,
322 		{ NULL, NULL, NULL }
323 	},
324 	{ 'P', &P__optname,
325 		STRING, 0, NULL, opt__P,
326 		{ "prompt: ", NULL, NULL }
327 	},
328 	{ 'q', &q_optname,
329 		TRIPLE, OPT_OFF, &quiet, NULL,
330 		{
331 			"Ring the bell for errors AND at eof/bof",
332 			"Ring the bell for errors but not at eof/bof",
333 			"Never ring the bell"
334 		}
335 	},
336 	{ 'r', &r_optname,
337 		TRIPLE|REPAINT, OPT_OFF, &ctldisp, NULL,
338 		{
339 			"Display control characters as ^X",
340 			"Display control characters directly",
341 			"Display control characters directly, processing ANSI sequences"
342 		}
343 	},
344 	{ 's', &s_optname,
345 		BOOL|REPAINT, OPT_OFF, &squeeze, NULL,
346 		{
347 			"Display all blank lines",
348 			"Squeeze multiple blank lines",
349 			NULL
350 		}
351 	},
352 	{ 'S', &S__optname,
353 		BOOL|REPAINT, OPT_OFF, &chopline, NULL,
354 		{
355 			"Fold long lines",
356 			"Chop long lines",
357 			NULL
358 		}
359 	},
360 #if TAGS
361 	{ 't', &t_optname,
362 		STRING|NO_QUERY, 0, NULL, opt_t,
363 		{ "tag: ", NULL, NULL }
364 	},
365 	{ 'T', &T__optname,
366 		STRING, 0, NULL, opt__T,
367 		{ "tags file: ", NULL, NULL }
368 	},
369 #endif
370 	{ 'u', &u_optname,
371 		TRIPLE|REPAINT, OPT_OFF, &bs_mode, NULL,
372 		{
373 			"Display underlined text in underline mode",
374 			"Backspaces cause overstrike",
375 			"Print backspace as ^H"
376 		}
377 	},
378 	{ 'V', &V__optname,
379 		NOVAR, 0, NULL, opt__V,
380 		{ NULL, NULL, NULL }
381 	},
382 	{ 'w', &w_optname,
383 		TRIPLE|REPAINT, OPT_OFF, &show_attn, NULL,
384 		{
385 			"Don't highlight first unread line",
386 			"Highlight first unread line after forward-screen",
387 			"Highlight first unread line after any forward movement",
388 		}
389 	},
390 	{ 'x', &x_optname,
391 		STRING|REPAINT, 0, NULL, opt_x,
392 		{
393 			"Tab stops: ",
394 			"0123456789,",
395 			NULL
396 		}
397 	},
398 	{ 'X', &X__optname,
399 		BOOL|NO_TOGGLE, OPT_OFF, &no_init, NULL,
400 		{
401 			"Send init/deinit strings to terminal",
402 			"Don't use init/deinit strings",
403 			NULL
404 		}
405 	},
406 	{ 'y', &y_optname,
407 		NUMBER, -1, &forw_scroll, NULL,
408 		{
409 			"Forward scroll limit: ",
410 			"Forward scroll limit is %d lines",
411 			NULL
412 		}
413 	},
414 	{ 'z', &z_optname,
415 		NUMBER, -1, &swindow, NULL,
416 		{
417 			"Scroll window size: ",
418 			"Scroll window size is %d lines",
419 			NULL
420 		}
421 	},
422 	{ '"', &quote_optname,
423 		STRING, 0, NULL, opt_quote,
424 		{ "quotes: ", NULL, NULL }
425 	},
426 	{ '~', &tilde_optname,
427 		BOOL|REPAINT, OPT_ON, &twiddle, NULL,
428 		{
429 			"Don't show tildes after end of file",
430 			"Show tildes after end of file",
431 			NULL
432 		}
433 	},
434 	{ '?', &query_optname,
435 		NOVAR, 0, NULL, opt_query,
436 		{ NULL, NULL, NULL }
437 	},
438 	{ '#', &pound_optname,
439 		STRING, 0, NULL, opt_shift,
440 		{
441 			"Horizontal shift: ",
442 			"0123456789.",
443 			NULL
444 		}
445 	},
446 	{ OLETTER_NONE, &keypad_optname,
447 		BOOL|NO_TOGGLE, OPT_OFF, &no_keypad, NULL,
448 		{
449 			"Use keypad mode",
450 			"Don't use keypad mode",
451 			NULL
452 		}
453 	},
454 	{ OLETTER_NONE, &oldbot_optname,
455 		BOOL, OPT_OFF, &oldbot, NULL,
456 		{
457 			"Use new bottom of screen behavior",
458 			"Use old bottom of screen behavior",
459 			NULL
460 		}
461 	},
462 	{ OLETTER_NONE, &follow_optname,
463 		BOOL, FOLLOW_DESC, &follow_mode, NULL,
464 		{
465 			"F command follows file descriptor",
466 			"F command follows file name",
467 			NULL
468 		}
469 	},
470 	{ OLETTER_NONE, &use_backslash_optname,
471 		BOOL, OPT_OFF, &opt_use_backslash, NULL,
472 		{
473 			"Use backslash escaping in command line parameters",
474 			"Don't use backslash escaping in command line parameters",
475 			NULL
476 		}
477 	},
478 	{ OLETTER_NONE, &rscroll_optname,
479 		STRING|REPAINT|INIT_HANDLER, 0, NULL, opt_rscroll,
480 		{ "right scroll character: ", NULL, NULL }
481 	},
482 	{ OLETTER_NONE, &nohistdups_optname,
483 		BOOL, OPT_OFF, &no_hist_dups, NULL,
484 		{
485 			"Allow duplicates in history list",
486 			"Remove duplicates from history list",
487 			NULL
488 		}
489 	},
490 	{ OLETTER_NONE, &mousecap_optname,
491 		TRIPLE, OPT_OFF, &mousecap, opt_mousecap,
492 		{
493 			"Ignore mouse input",
494 			"Use the mouse for scrolling",
495 			"Use the mouse for scrolling (reverse)"
496 		}
497 	},
498 	{ OLETTER_NONE, &wheel_lines_optname,
499 		NUMBER|INIT_HANDLER, 0, &wheel_lines, opt_wheel_lines,
500 		{
501 			"Lines to scroll on mouse wheel: ",
502 			"Scroll %d line(s) on mouse wheel",
503 			NULL
504 		}
505 	},
506 	{ OLETTER_NONE, &perma_marks_optname,
507 		BOOL, OPT_OFF, &perma_marks, NULL,
508 		{
509 			"Don't save marks in history file",
510 			"Save marks in history file",
511 			NULL
512 		}
513 	},
514 	{ OLETTER_NONE, &linenum_width_optname,
515 		NUMBER|REPAINT, MIN_LINENUM_WIDTH, &linenum_width, opt_linenum_width,
516 		{
517 			"Line number width: ",
518 			"Line number width is %d chars",
519 			NULL
520 		}
521 	},
522 	{ OLETTER_NONE, &status_col_width_optname,
523 		NUMBER|REPAINT, 2, &status_col_width, opt_status_col_width,
524 		{
525 			"Status column width: ",
526 			"Status column width is %d chars",
527 			NULL
528 		}
529 	},
530 	{ OLETTER_NONE, &incr_search_optname,
531 		BOOL, OPT_OFF, &incr_search, NULL,
532 		{
533 			"Incremental search is off",
534 			"Incremental search is on",
535 			NULL
536 		}
537 	},
538 	{ OLETTER_NONE, &use_color_optname,
539 		BOOL|REPAINT, OPT_OFF, &use_color, NULL,
540 		{
541 			"Don't use color",
542 			"Use color",
543 			NULL
544 		}
545 	},
546 #if LESSTEST
547 	{ OLETTER_NONE, &ttyin_name_optname,
548 		STRING|NO_TOGGLE, 0, NULL, opt_ttyin_name,
549 		{
550 			NULL,
551 			NULL,
552 			NULL
553 		}
554 	},
555 	{ OLETTER_NONE, &rstat_optname,
556 		STRING|NO_TOGGLE, 0, NULL, opt_rstat,
557 		{
558 			NULL,
559 			NULL,
560 			NULL
561 		}
562 	},
563 #endif /*LESSTEST*/
564 	{ '\0', NULL, NOVAR, 0, NULL, NULL, { NULL, NULL, NULL } }
565 };
566 
567 
568 /*
569  * Initialize each option to its default value.
570  */
571 	public void
572 init_option(VOID_PARAM)
573 {
574 	struct loption *o;
575 	char *p;
576 
577 	p = lgetenv("LESS_IS_MORE");
578 	if (!isnullenv(p))
579 		less_is_more = 1;
580 
581 	for (o = option;  o->oletter != '\0';  o++)
582 	{
583 		/*
584 		 * Set each variable to its default.
585 		 */
586 		if (o->ovar != NULL)
587 			*(o->ovar) = o->odefault;
588 		if (o->otype & INIT_HANDLER)
589 			(*(o->ofunc))(INIT, (char *) NULL);
590 	}
591 }
592 
593 /*
594  * Find an option in the option table, given its option letter.
595  */
596 	public struct loption *
597 findopt(c)
598 	int c;
599 {
600 	struct loption *o;
601 
602 	for (o = option;  o->oletter != '\0';  o++)
603 	{
604 		if (o->oletter == c)
605 			return (o);
606 		if ((o->otype & TRIPLE) && ASCII_TO_UPPER(o->oletter) == c)
607 			return (o);
608 	}
609 	return (NULL);
610 }
611 
612 /*
613  *
614  */
615 	static int
616 is_optchar(c)
617 	char c;
618 {
619 	if (ASCII_IS_UPPER(c))
620 		return 1;
621 	if (ASCII_IS_LOWER(c))
622 		return 1;
623 	if (c == '-')
624 		return 1;
625 	return 0;
626 }
627 
628 /*
629  * Find an option in the option table, given its option name.
630  * p_optname is the (possibly partial) name to look for, and
631  * is updated to point after the matched name.
632  * p_oname if non-NULL is set to point to the full option name.
633  */
634 	public struct loption *
635 findopt_name(p_optname, p_oname, p_err)
636 	char **p_optname;
637 	char **p_oname;
638 	int *p_err;
639 {
640 	char *optname = *p_optname;
641 	struct loption *o;
642 	struct optname *oname;
643 	int len;
644 	int uppercase;
645 	struct loption *maxo = NULL;
646 	struct optname *maxoname = NULL;
647 	int maxlen = 0;
648 	int ambig = 0;
649 	int exact = 0;
650 
651 	/*
652 	 * Check all options.
653 	 */
654 	for (o = option;  o->oletter != '\0';  o++)
655 	{
656 		/*
657 		 * Check all names for this option.
658 		 */
659 		for (oname = o->onames;  oname != NULL;  oname = oname->onext)
660 		{
661 			/*
662 			 * Try normal match first (uppercase == 0),
663 			 * then, then if it's a TRIPLE option,
664 			 * try uppercase match (uppercase == 1).
665 			 */
666 			for (uppercase = 0;  uppercase <= 1;  uppercase++)
667 			{
668 				len = sprefix(optname, oname->oname, uppercase);
669 				if (len <= 0 || is_optchar(optname[len]))
670 				{
671 					/*
672 					 * We didn't use all of the option name.
673 					 */
674 					continue;
675 				}
676 				if (!exact && len == maxlen)
677 					/*
678 					 * Already had a partial match,
679 					 * and now there's another one that
680 					 * matches the same length.
681 					 */
682 					ambig = 1;
683 				else if (len > maxlen)
684 				{
685 					/*
686 					 * Found a better match than
687 					 * the one we had.
688 					 */
689 					maxo = o;
690 					maxoname = oname;
691 					maxlen = len;
692 					ambig = 0;
693 					exact = (len == (int)strlen(oname->oname));
694 				}
695 				if (!(o->otype & TRIPLE))
696 					break;
697 			}
698 		}
699 	}
700 	if (ambig)
701 	{
702 		/*
703 		 * Name matched more than one option.
704 		 */
705 		if (p_err != NULL)
706 			*p_err = OPT_AMBIG;
707 		return (NULL);
708 	}
709 	*p_optname = optname + maxlen;
710 	if (p_oname != NULL)
711 		*p_oname = maxoname == NULL ? NULL : maxoname->oname;
712 	return (maxo);
713 }
714