xref: /freebsd/contrib/less/opttbl.c (revision 2b8331622f0b212cf3bb4fc4914a501e5321d506)
1 /*
2  * Copyright (C) 1984-2022  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 public int want_filesize;       /* Scan to EOF if necessary to get file size */
67 public int status_line;         /* Highlight entire marked lines */
68 public int header_lines;        /* Freeze header lines at top of screen */
69 public int header_cols;         /* Freeze header columns at left of screen */
70 public int nonum_headers;       /* Don't give headers line numbers */
71 public int redraw_on_quit;      /* Redraw last screen after term deinit */
72 public int def_search_type;     /* */
73 public int exit_F_on_close;     /* Exit F command when input closes */
74 #if HILITE_SEARCH
75 public int hilite_search;       /* Highlight matched search patterns? */
76 #endif
77 
78 public int less_is_more = 0;    /* Make compatible with POSIX more */
79 
80 /*
81  * Long option names.
82  */
83 static struct optname a_optname      = { "search-skip-screen",   NULL };
84 static struct optname b_optname      = { "buffers",              NULL };
85 static struct optname B__optname     = { "auto-buffers",         NULL };
86 static struct optname c_optname      = { "clear-screen",         NULL };
87 static struct optname d_optname      = { "dumb",                 NULL };
88 static struct optname D__optname     = { "color",                NULL };
89 static struct optname e_optname      = { "quit-at-eof",          NULL };
90 static struct optname f_optname      = { "force",                NULL };
91 static struct optname F__optname     = { "quit-if-one-screen",   NULL };
92 #if HILITE_SEARCH
93 static struct optname g_optname      = { "hilite-search",        NULL };
94 #endif
95 static struct optname h_optname      = { "max-back-scroll",      NULL };
96 static struct optname i_optname      = { "ignore-case",          NULL };
97 static struct optname j_optname      = { "jump-target",          NULL };
98 static struct optname J__optname     = { "status-column",        NULL };
99 #if USERFILE
100 static struct optname k_optname      = { "lesskey-file",         NULL };
101 #if HAVE_LESSKEYSRC
102 static struct optname ks_optname     = { "lesskey-src",          NULL };
103 #endif /* HAVE_LESSKEYSRC */
104 #endif
105 static struct optname K__optname     = { "quit-on-intr",         NULL };
106 static struct optname L__optname     = { "no-lessopen",          NULL };
107 static struct optname m_optname      = { "long-prompt",          NULL };
108 static struct optname n_optname      = { "line-numbers",         NULL };
109 #if LOGFILE
110 static struct optname o_optname      = { "log-file",             NULL };
111 static struct optname O__optname     = { "LOG-FILE",             NULL };
112 #endif
113 static struct optname p_optname      = { "pattern",              NULL };
114 static struct optname P__optname     = { "prompt",               NULL };
115 static struct optname q2_optname     = { "silent",               NULL };
116 static struct optname q_optname      = { "quiet",                &q2_optname };
117 static struct optname r_optname      = { "raw-control-chars",    NULL };
118 static struct optname s_optname      = { "squeeze-blank-lines",  NULL };
119 static struct optname S__optname     = { "chop-long-lines",      NULL };
120 #if TAGS
121 static struct optname t_optname      = { "tag",                  NULL };
122 static struct optname T__optname     = { "tag-file",             NULL };
123 #endif
124 static struct optname u_optname      = { "underline-special",    NULL };
125 static struct optname V__optname     = { "version",              NULL };
126 static struct optname w_optname      = { "hilite-unread",        NULL };
127 static struct optname x_optname      = { "tabs",                 NULL };
128 static struct optname X__optname     = { "no-init",              NULL };
129 static struct optname y_optname      = { "max-forw-scroll",      NULL };
130 static struct optname z_optname      = { "window",               NULL };
131 static struct optname quote_optname  = { "quotes",               NULL };
132 static struct optname tilde_optname  = { "tilde",                NULL };
133 static struct optname query_optname  = { "help",                 NULL };
134 static struct optname pound_optname  = { "shift",                NULL };
135 static struct optname keypad_optname = { "no-keypad",            NULL };
136 static struct optname oldbot_optname = { "old-bot",              NULL };
137 static struct optname follow_optname = { "follow-name",          NULL };
138 static struct optname use_backslash_optname = { "use-backslash", NULL };
139 static struct optname rscroll_optname = { "rscroll", NULL };
140 static struct optname nohistdups_optname = { "no-histdups",      NULL };
141 static struct optname mousecap_optname = { "mouse",              NULL };
142 static struct optname wheel_lines_optname = { "wheel-lines",     NULL };
143 static struct optname perma_marks_optname = { "save-marks",      NULL };
144 static struct optname linenum_width_optname = { "line-num-width", NULL };
145 static struct optname status_col_width_optname = { "status-col-width", NULL };
146 static struct optname incr_search_optname = { "incsearch",       NULL };
147 static struct optname use_color_optname = { "use-color",         NULL };
148 static struct optname want_filesize_optname = { "file-size",     NULL };
149 static struct optname status_line_optname = { "status-line",     NULL };
150 static struct optname header_optname = { "header",               NULL };
151 static struct optname nonum_headers_optname = { "no-number-headers", NULL };
152 static struct optname redraw_on_quit_optname = { "redraw-on-quit", NULL };
153 static struct optname search_type_optname = { "search-options", NULL };
154 static struct optname exit_F_on_close_optname = { "exit-follow-on-close", NULL };
155 #if LESSTEST
156 static struct optname ttyin_name_optname = { "tty",              NULL };
157 static struct optname rstat_optname  = { "rstat",                NULL };
158 #endif /*LESSTEST*/
159 
160 
161 /*
162  * Table of all options and their semantics.
163  *
164  * For BOOL and TRIPLE options, odesc[0], odesc[1], odesc[2] are
165  * the description of the option when set to 0, 1 or 2, respectively.
166  * For NUMBER options, odesc[0] is the prompt to use when entering
167  * a new value, and odesc[1] is the description, which should contain
168  * one %d which is replaced by the value of the number.
169  * For STRING options, odesc[0] is the prompt to use when entering
170  * a new value, and odesc[1], if not NULL, is the set of characters
171  * that are valid in the string.
172  */
173 static struct loption option[] =
174 {
175 	{ 'a', &a_optname,
176 		TRIPLE, OPT_ONPLUS, &how_search, NULL,
177 		{
178 			"Search includes displayed screen",
179 			"Search skips displayed screen",
180 			"Search includes all of displayed screen"
181 		}
182 	},
183 
184 	{ 'b', &b_optname,
185 		NUMBER|INIT_HANDLER, 64, &bufspace, opt_b,
186 		{
187 			"Max buffer space per file (K): ",
188 			"Max buffer space per file: %dK",
189 			NULL
190 		}
191 	},
192 	{ 'B', &B__optname,
193 		BOOL, OPT_ON, &autobuf, NULL,
194 		{
195 			"Don't automatically allocate buffers",
196 			"Automatically allocate buffers when needed",
197 			NULL
198 		}
199 	},
200 	{ 'c', &c_optname,
201 		TRIPLE, OPT_OFF, &top_scroll, NULL,
202 		{
203 			"Repaint by scrolling from bottom of screen",
204 			"Repaint by painting from top of screen",
205 			"Repaint by painting from top of screen"
206 		}
207 	},
208 	{ 'd', &d_optname,
209 		BOOL|NO_TOGGLE, OPT_OFF, &know_dumb, NULL,
210 		{
211 			"Assume intelligent terminal",
212 			"Assume dumb terminal",
213 			NULL
214 		}
215 	},
216 	{ 'D', &D__optname,
217 		STRING|REPAINT|NO_QUERY, 0, NULL, opt_D,
218 		{
219 			"color desc: ",
220 			NULL,
221 			NULL
222 		}
223 	},
224 	{ 'e', &e_optname,
225 		TRIPLE, OPT_OFF, &quit_at_eof, NULL,
226 		{
227 			"Don't quit at end-of-file",
228 			"Quit at end-of-file",
229 			"Quit immediately at end-of-file"
230 		}
231 	},
232 	{ 'f', &f_optname,
233 		BOOL, OPT_OFF, &force_open, NULL,
234 		{
235 			"Open only regular files",
236 			"Open even non-regular files",
237 			NULL
238 		}
239 	},
240 	{ 'F', &F__optname,
241 		BOOL, OPT_OFF, &quit_if_one_screen, NULL,
242 		{
243 			"Don't quit if end-of-file on first screen",
244 			"Quit if end-of-file on first screen",
245 			NULL
246 		}
247 	},
248 #if HILITE_SEARCH
249 	{ 'g', &g_optname,
250 		TRIPLE|HL_REPAINT, OPT_ONPLUS, &hilite_search, NULL,
251 		{
252 			"Don't highlight search matches",
253 			"Highlight matches for previous search only",
254 			"Highlight all matches for previous search pattern",
255 		}
256 	},
257 #endif
258 	{ 'h', &h_optname,
259 		NUMBER, -1, &back_scroll, NULL,
260 		{
261 			"Backwards scroll limit: ",
262 			"Backwards scroll limit is %d lines",
263 			NULL
264 		}
265 	},
266 	{ 'i', &i_optname,
267 		TRIPLE|HL_REPAINT, OPT_OFF, &caseless, opt_i,
268 		{
269 			"Case is significant in searches",
270 			"Ignore case in searches",
271 			"Ignore case in searches and in patterns"
272 		}
273 	},
274 	{ 'j', &j_optname,
275 		STRING, 0, NULL, opt_j,
276 		{
277 			"Target line: ",
278 			"0123456789.-",
279 			NULL
280 		}
281 	},
282 	{ 'J', &J__optname,
283 		BOOL|REPAINT, OPT_OFF, &status_col, NULL,
284 		{
285 			"Don't display a status column",
286 			"Display a status column",
287 			NULL
288 		}
289 	},
290 #if USERFILE
291 	{ 'k', &k_optname,
292 		STRING|NO_TOGGLE|NO_QUERY, 0, NULL, opt_k,
293 		{ NULL, NULL, NULL }
294 	},
295 #if HAVE_LESSKEYSRC
296 	{ OLETTER_NONE, &ks_optname,
297 		STRING|NO_TOGGLE|NO_QUERY, 0, NULL, opt_ks,
298 		{ NULL, NULL, NULL }
299 	},
300 #endif /* HAVE_LESSKEYSRC */
301 #endif
302 	{ 'K', &K__optname,
303 		BOOL, OPT_OFF, &quit_on_intr, NULL,
304 		{
305 			"Interrupt (ctrl-C) returns to prompt",
306 			"Interrupt (ctrl-C) exits less",
307 			NULL
308 		}
309 	},
310 	{ 'L', &L__optname,
311 		BOOL, OPT_ON, &use_lessopen, NULL,
312 		{
313 			"Don't use the LESSOPEN filter",
314 			"Use the LESSOPEN filter",
315 			NULL
316 		}
317 	},
318 	{ 'm', &m_optname,
319 		TRIPLE, OPT_OFF, &pr_type, NULL,
320 		{
321 			"Short prompt",
322 			"Medium prompt",
323 			"Long prompt"
324 		}
325 	},
326 	{ 'n', &n_optname,
327 		TRIPLE|REPAINT, OPT_ON, &linenums, NULL,
328 		{
329 			"Don't use line numbers",
330 			"Use line numbers",
331 			"Constantly display line numbers"
332 		}
333 	},
334 #if LOGFILE
335 	{ 'o', &o_optname,
336 		STRING, 0, NULL, opt_o,
337 		{ "log file: ", NULL, NULL }
338 	},
339 	{ 'O', &O__optname,
340 		STRING, 0, NULL, opt__O,
341 		{ "Log file: ", NULL, NULL }
342 	},
343 #endif
344 	{ 'p', &p_optname,
345 		STRING|NO_TOGGLE|NO_QUERY, 0, NULL, opt_p,
346 		{ NULL, NULL, NULL }
347 	},
348 	{ 'P', &P__optname,
349 		STRING, 0, NULL, opt__P,
350 		{ "prompt: ", NULL, NULL }
351 	},
352 	{ 'q', &q_optname,
353 		TRIPLE, OPT_OFF, &quiet, NULL,
354 		{
355 			"Ring the bell for errors AND at eof/bof",
356 			"Ring the bell for errors but not at eof/bof",
357 			"Never ring the bell"
358 		}
359 	},
360 	{ 'r', &r_optname,
361 		TRIPLE|REPAINT, OPT_OFF, &ctldisp, NULL,
362 		{
363 			"Display control characters as ^X",
364 			"Display control characters directly (not recommended)",
365 			"Display ANSI sequences directly, other control characters as ^X"
366 		}
367 	},
368 	{ 's', &s_optname,
369 		BOOL|REPAINT, OPT_OFF, &squeeze, NULL,
370 		{
371 			"Display all blank lines",
372 			"Squeeze multiple blank lines",
373 			NULL
374 		}
375 	},
376 	{ 'S', &S__optname,
377 		BOOL|REPAINT, OPT_OFF, &chopline, NULL,
378 		{
379 			"Fold long lines",
380 			"Chop long lines",
381 			NULL
382 		}
383 	},
384 #if TAGS
385 	{ 't', &t_optname,
386 		STRING|NO_QUERY, 0, NULL, opt_t,
387 		{ "tag: ", NULL, NULL }
388 	},
389 	{ 'T', &T__optname,
390 		STRING, 0, NULL, opt__T,
391 		{ "tags file: ", NULL, NULL }
392 	},
393 #endif
394 	{ 'u', &u_optname,
395 		TRIPLE|REPAINT, OPT_OFF, &bs_mode, NULL,
396 		{
397 			"Display underlined text in underline mode",
398 			"Backspaces cause overstrike",
399 			"Print backspace as ^H"
400 		}
401 	},
402 	{ 'V', &V__optname,
403 		NOVAR, 0, NULL, opt__V,
404 		{ NULL, NULL, NULL }
405 	},
406 	{ 'w', &w_optname,
407 		TRIPLE|REPAINT, OPT_OFF, &show_attn, NULL,
408 		{
409 			"Don't highlight first unread line",
410 			"Highlight first unread line after forward-screen",
411 			"Highlight first unread line after any forward movement",
412 		}
413 	},
414 	{ 'x', &x_optname,
415 		STRING|REPAINT, 0, NULL, opt_x,
416 		{
417 			"Tab stops: ",
418 			"0123456789,",
419 			NULL
420 		}
421 	},
422 	{ 'X', &X__optname,
423 		BOOL|NO_TOGGLE, OPT_OFF, &no_init, NULL,
424 		{
425 			"Send init/deinit strings to terminal",
426 			"Don't use init/deinit strings",
427 			NULL
428 		}
429 	},
430 	{ 'y', &y_optname,
431 		NUMBER, -1, &forw_scroll, NULL,
432 		{
433 			"Forward scroll limit: ",
434 			"Forward scroll limit is %d lines",
435 			NULL
436 		}
437 	},
438 	{ 'z', &z_optname,
439 		NUMBER, -1, &swindow, NULL,
440 		{
441 			"Scroll window size: ",
442 			"Scroll window size is %d lines",
443 			NULL
444 		}
445 	},
446 	{ '"', &quote_optname,
447 		STRING, 0, NULL, opt_quote,
448 		{ "quotes: ", NULL, NULL }
449 	},
450 	{ '~', &tilde_optname,
451 		BOOL|REPAINT, OPT_ON, &twiddle, NULL,
452 		{
453 			"Don't show tildes after end of file",
454 			"Show tildes after end of file",
455 			NULL
456 		}
457 	},
458 	{ '?', &query_optname,
459 		NOVAR, 0, NULL, opt_query,
460 		{ NULL, NULL, NULL }
461 	},
462 	{ '#', &pound_optname,
463 		STRING, 0, NULL, opt_shift,
464 		{
465 			"Horizontal shift: ",
466 			"0123456789.",
467 			NULL
468 		}
469 	},
470 	{ OLETTER_NONE, &keypad_optname,
471 		BOOL|NO_TOGGLE, OPT_OFF, &no_keypad, NULL,
472 		{
473 			"Use keypad mode",
474 			"Don't use keypad mode",
475 			NULL
476 		}
477 	},
478 	{ OLETTER_NONE, &oldbot_optname,
479 		BOOL, OPT_OFF, &oldbot, NULL,
480 		{
481 			"Use new bottom of screen behavior",
482 			"Use old bottom of screen behavior",
483 			NULL
484 		}
485 	},
486 	{ OLETTER_NONE, &follow_optname,
487 		BOOL, FOLLOW_DESC, &follow_mode, NULL,
488 		{
489 			"F command follows file descriptor",
490 			"F command follows file name",
491 			NULL
492 		}
493 	},
494 	{ OLETTER_NONE, &use_backslash_optname,
495 		BOOL, OPT_OFF, &opt_use_backslash, NULL,
496 		{
497 			"Use backslash escaping in command line parameters",
498 			"Don't use backslash escaping in command line parameters",
499 			NULL
500 		}
501 	},
502 	{ OLETTER_NONE, &rscroll_optname,
503 		STRING|REPAINT|INIT_HANDLER, 0, NULL, opt_rscroll,
504 		{ "right scroll character: ", NULL, NULL }
505 	},
506 	{ OLETTER_NONE, &nohistdups_optname,
507 		BOOL, OPT_OFF, &no_hist_dups, NULL,
508 		{
509 			"Allow duplicates in history list",
510 			"Remove duplicates from history list",
511 			NULL
512 		}
513 	},
514 	{ OLETTER_NONE, &mousecap_optname,
515 		TRIPLE, OPT_OFF, &mousecap, opt_mousecap,
516 		{
517 			"Ignore mouse input",
518 			"Use the mouse for scrolling",
519 			"Use the mouse for scrolling (reverse)"
520 		}
521 	},
522 	{ OLETTER_NONE, &wheel_lines_optname,
523 		NUMBER|INIT_HANDLER, 0, &wheel_lines, opt_wheel_lines,
524 		{
525 			"Lines to scroll on mouse wheel: ",
526 			"Scroll %d line(s) on mouse wheel",
527 			NULL
528 		}
529 	},
530 	{ OLETTER_NONE, &perma_marks_optname,
531 		BOOL, OPT_OFF, &perma_marks, NULL,
532 		{
533 			"Don't save marks in history file",
534 			"Save marks in history file",
535 			NULL
536 		}
537 	},
538 	{ OLETTER_NONE, &linenum_width_optname,
539 		NUMBER|REPAINT, MIN_LINENUM_WIDTH, &linenum_width, opt_linenum_width,
540 		{
541 			"Line number width: ",
542 			"Line number width is %d chars",
543 			NULL
544 		}
545 	},
546 	{ OLETTER_NONE, &status_col_width_optname,
547 		NUMBER|REPAINT, 2, &status_col_width, opt_status_col_width,
548 		{
549 			"Status column width: ",
550 			"Status column width is %d chars",
551 			NULL
552 		}
553 	},
554 	{ OLETTER_NONE, &incr_search_optname,
555 		BOOL, OPT_OFF, &incr_search, NULL,
556 		{
557 			"Incremental search is off",
558 			"Incremental search is on",
559 			NULL
560 		}
561 	},
562 	{ OLETTER_NONE, &use_color_optname,
563 		BOOL|REPAINT, OPT_OFF, &use_color, NULL,
564 		{
565 			"Don't use color",
566 			"Use color",
567 			NULL
568 		}
569 	},
570 	{ OLETTER_NONE, &want_filesize_optname,
571 		BOOL|REPAINT, OPT_OFF, &want_filesize, opt_filesize,
572 		{
573 			"Don't get size of each file",
574 			"Get size of each file",
575 			NULL
576 		}
577 	},
578 	{ OLETTER_NONE, &status_line_optname,
579 		BOOL|REPAINT, OPT_OFF, &status_line, NULL,
580 		{
581 			"Don't color each line with its status column color",
582 			"Color each line with its status column color",
583 			NULL
584 		}
585 	},
586 	{ OLETTER_NONE, &header_optname,
587 		STRING|REPAINT, 0, NULL, opt_header,
588 		{
589 			"Header lines: ",
590 			NULL,
591 			NULL
592 		}
593 	},
594 	{ OLETTER_NONE, &nonum_headers_optname,
595 		BOOL|REPAINT, 0, &nonum_headers, NULL,
596 		{
597 			"Number header lines",
598 			"Don't number header lines",
599 			NULL
600 		}
601 	},
602 	{ OLETTER_NONE, &redraw_on_quit_optname,
603 		BOOL, OPT_OFF, &redraw_on_quit, NULL,
604 		{
605 			"Don't redraw screen when quitting",
606 			"Redraw last screen when quitting",
607 			NULL
608 		}
609 	},
610 	{ OLETTER_NONE, &search_type_optname,
611 		STRING, 0, NULL, opt_search_type,
612 		{
613 			"Search options: ",
614 			NULL,
615 			NULL
616 		}
617 	},
618 	{ OLETTER_NONE, &exit_F_on_close_optname,
619 		BOOL, OPT_OFF, &exit_F_on_close, NULL,
620 		{
621 			"Don't exit F command when input closes",
622 			"Exit F command when input closes",
623 			NULL
624 		}
625 	},
626 #if LESSTEST
627 	{ OLETTER_NONE, &ttyin_name_optname,
628 		STRING|NO_TOGGLE, 0, NULL, opt_ttyin_name,
629 		{
630 			NULL,
631 			NULL,
632 			NULL
633 		}
634 	},
635 	{ OLETTER_NONE, &rstat_optname,
636 		STRING|NO_TOGGLE, 0, NULL, opt_rstat,
637 		{
638 			NULL,
639 			NULL,
640 			NULL
641 		}
642 	},
643 #endif /*LESSTEST*/
644 	{ '\0', NULL, NOVAR, 0, NULL, NULL, { NULL, NULL, NULL } }
645 };
646 
647 
648 /*
649  * Initialize each option to its default value.
650  */
651 	public void
652 init_option(VOID_PARAM)
653 {
654 	struct loption *o;
655 	char *p;
656 
657 	p = lgetenv("LESS_IS_MORE");
658 	if (!isnullenv(p))
659 		less_is_more = 1;
660 
661 	for (o = option;  o->oletter != '\0';  o++)
662 	{
663 		/*
664 		 * Set each variable to its default.
665 		 */
666 		if (o->ovar != NULL)
667 			*(o->ovar) = o->odefault;
668 		if (o->otype & INIT_HANDLER)
669 			(*(o->ofunc))(INIT, (char *) NULL);
670 	}
671 }
672 
673 /*
674  * Find an option in the option table, given its option letter.
675  */
676 	public struct loption *
677 findopt(c)
678 	int c;
679 {
680 	struct loption *o;
681 
682 	for (o = option;  o->oletter != '\0';  o++)
683 	{
684 		if (o->oletter == c)
685 			return (o);
686 		if ((o->otype & TRIPLE) && ASCII_TO_UPPER(o->oletter) == c)
687 			return (o);
688 	}
689 	return (NULL);
690 }
691 
692 /*
693  *
694  */
695 	static int
696 is_optchar(c)
697 	char c;
698 {
699 	if (ASCII_IS_UPPER(c))
700 		return 1;
701 	if (ASCII_IS_LOWER(c))
702 		return 1;
703 	if (c == '-')
704 		return 1;
705 	return 0;
706 }
707 
708 /*
709  * Find an option in the option table, given its option name.
710  * p_optname is the (possibly partial) name to look for, and
711  * is updated to point after the matched name.
712  * p_oname if non-NULL is set to point to the full option name.
713  */
714 	public struct loption *
715 findopt_name(p_optname, p_oname, p_err)
716 	char **p_optname;
717 	char **p_oname;
718 	int *p_err;
719 {
720 	char *optname = *p_optname;
721 	struct loption *o;
722 	struct optname *oname;
723 	int len;
724 	int uppercase;
725 	struct loption *maxo = NULL;
726 	struct optname *maxoname = NULL;
727 	int maxlen = 0;
728 	int ambig = 0;
729 	int exact = 0;
730 
731 	/*
732 	 * Check all options.
733 	 */
734 	for (o = option;  o->oletter != '\0';  o++)
735 	{
736 		/*
737 		 * Check all names for this option.
738 		 */
739 		for (oname = o->onames;  oname != NULL;  oname = oname->onext)
740 		{
741 			/*
742 			 * Try normal match first (uppercase == 0),
743 			 * then, then if it's a TRIPLE option,
744 			 * try uppercase match (uppercase == 1).
745 			 */
746 			for (uppercase = 0;  uppercase <= 1;  uppercase++)
747 			{
748 				len = sprefix(optname, oname->oname, uppercase);
749 				if (len <= 0 || is_optchar(optname[len]))
750 				{
751 					/*
752 					 * We didn't use all of the option name.
753 					 */
754 					continue;
755 				}
756 				if (!exact && len == maxlen)
757 					/*
758 					 * Already had a partial match,
759 					 * and now there's another one that
760 					 * matches the same length.
761 					 */
762 					ambig = 1;
763 				else if (len > maxlen)
764 				{
765 					/*
766 					 * Found a better match than
767 					 * the one we had.
768 					 */
769 					maxo = o;
770 					maxoname = oname;
771 					maxlen = len;
772 					ambig = 0;
773 					exact = (len == (int)strlen(oname->oname));
774 				}
775 				if (!(o->otype & TRIPLE))
776 					break;
777 			}
778 		}
779 	}
780 	if (ambig)
781 	{
782 		/*
783 		 * Name matched more than one option.
784 		 */
785 		if (p_err != NULL)
786 			*p_err = OPT_AMBIG;
787 		return (NULL);
788 	}
789 	*p_optname = optname + maxlen;
790 	if (p_oname != NULL)
791 		*p_oname = maxoname == NULL ? NULL : maxoname->oname;
792 	return (maxo);
793 }
794