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 */
21public int quiet;               /* Should we suppress the audible bell? */
22public int how_search;          /* Where should forward searches start? */
23public int top_scroll;          /* Repaint screen from top?
24                                   (alternative is scroll from bottom) */
25public int pr_type;             /* Type of prompt (short, medium, long) */
26public int bs_mode;             /* How to process backspaces */
27public int know_dumb;           /* Don't complain about dumb terminals */
28public int quit_at_eof;         /* Quit after hitting end of file twice */
29public int quit_if_one_screen;  /* Quit if EOF on first screen */
30public int squeeze;             /* Squeeze multiple blank lines into one */
31public int tabstop;             /* Tab settings */
32public int back_scroll;         /* Repaint screen on backwards movement */
33public int forw_scroll;         /* Repaint screen on forward movement */
34public int caseless;            /* Do "caseless" searches */
35public int linenums;            /* Use line numbers */
36public int autobuf;             /* Automatically allocate buffers as needed */
37public int bufspace;            /* Max buffer space per file (K) */
38public int ctldisp;             /* Send control chars to screen untranslated */
39public int force_open;          /* Open the file even if not regular file */
40public int swindow;             /* Size of scrolling window */
41public int jump_sline;          /* Screen line of "jump target" */
42public long jump_sline_fraction = -1;
43public long shift_count_fraction = -1;
44public int chopline;            /* Truncate displayed lines at screen width */
45public int no_init;             /* Disable sending ti/te termcap strings */
46public int no_keypad;           /* Disable sending ks/ke termcap strings */
47public int twiddle;             /* Show tildes after EOF */
48public int show_attn;           /* Hilite first unread line */
49public int shift_count;         /* Number of positions to shift horizontally */
50public int status_col;          /* Display a status column */
51public int use_lessopen;        /* Use the LESSOPEN filter */
52public int quit_on_intr;        /* Quit on interrupt */
53public int follow_mode;         /* F cmd Follows file desc or file name? */
54public int oldbot;              /* Old bottom of screen behavior {{REMOVE}} */
55public int opt_use_backslash;   /* Use backslash escaping in option parsing */
56public char rscroll_char;       /* Char which marks chopped lines with -S */
57public int rscroll_attr;        /* Attribute of rscroll_char */
58public int no_hist_dups;        /* Remove dups from history list */
59public int mousecap;            /* Allow mouse for scrolling */
60public int wheel_lines;         /* Number of lines to scroll on mouse wheel scroll */
61public int perma_marks;         /* Save marks in history file */
62public int linenum_width;       /* Width of line numbers */
63public int status_col_width;    /* Width of status column */
64public int incr_search;         /* Incremental search */
65public int use_color;           /* Use UI color */
66#if HILITE_SEARCH
67public int hilite_search;       /* Highlight matched search patterns? */
68#endif
69
70public int less_is_more = 0;    /* Make compatible with POSIX more */
71
72/*
73 * Long option names.
74 */
75static struct optname a_optname      = { "search-skip-screen",   NULL };
76static struct optname b_optname      = { "buffers",              NULL };
77static struct optname B__optname     = { "auto-buffers",         NULL };
78static struct optname c_optname      = { "clear-screen",         NULL };
79static struct optname d_optname      = { "dumb",                 NULL };
80static struct optname D__optname     = { "color",                NULL };
81static struct optname e_optname      = { "quit-at-eof",          NULL };
82static struct optname f_optname      = { "force",                NULL };
83static struct optname F__optname     = { "quit-if-one-screen",   NULL };
84#if HILITE_SEARCH
85static struct optname g_optname      = { "hilite-search",        NULL };
86#endif
87static struct optname h_optname      = { "max-back-scroll",      NULL };
88static struct optname i_optname      = { "ignore-case",          NULL };
89static struct optname j_optname      = { "jump-target",          NULL };
90static struct optname J__optname     = { "status-column",        NULL };
91#if USERFILE
92static struct optname k_optname      = { "lesskey-file",         NULL };
93#endif
94static struct optname K__optname     = { "quit-on-intr",         NULL };
95static struct optname L__optname     = { "no-lessopen",          NULL };
96static struct optname m_optname      = { "long-prompt",          NULL };
97static struct optname n_optname      = { "line-numbers",         NULL };
98#if LOGFILE
99static struct optname o_optname      = { "log-file",             NULL };
100static struct optname O__optname     = { "LOG-FILE",             NULL };
101#endif
102static struct optname p_optname      = { "pattern",              NULL };
103static struct optname P__optname     = { "prompt",               NULL };
104static struct optname q2_optname     = { "silent",               NULL };
105static struct optname q_optname      = { "quiet",                &q2_optname };
106static struct optname r_optname      = { "raw-control-chars",    NULL };
107static struct optname s_optname      = { "squeeze-blank-lines",  NULL };
108static struct optname S__optname     = { "chop-long-lines",      NULL };
109#if TAGS
110static struct optname t_optname      = { "tag",                  NULL };
111static struct optname T__optname     = { "tag-file",             NULL };
112#endif
113static struct optname u_optname      = { "underline-special",    NULL };
114static struct optname V__optname     = { "version",              NULL };
115static struct optname w_optname      = { "hilite-unread",        NULL };
116static struct optname x_optname      = { "tabs",                 NULL };
117static struct optname X__optname     = { "no-init",              NULL };
118static struct optname y_optname      = { "max-forw-scroll",      NULL };
119static struct optname z_optname      = { "window",               NULL };
120static struct optname quote_optname  = { "quotes",               NULL };
121static struct optname tilde_optname  = { "tilde",                NULL };
122static struct optname query_optname  = { "help",                 NULL };
123static struct optname pound_optname  = { "shift",                NULL };
124static struct optname keypad_optname = { "no-keypad",            NULL };
125static struct optname oldbot_optname = { "old-bot",              NULL };
126static struct optname follow_optname = { "follow-name",          NULL };
127static struct optname use_backslash_optname = { "use-backslash", NULL };
128static struct optname rscroll_optname = { "rscroll", NULL };
129static struct optname nohistdups_optname = { "no-histdups",      NULL };
130static struct optname mousecap_optname = { "mouse",              NULL };
131static struct optname wheel_lines_optname = { "wheel-lines",     NULL };
132static struct optname perma_marks_optname = { "save-marks",      NULL };
133static struct optname linenum_width_optname = { "line-num-width", NULL };
134static struct optname status_col_width_optname = { "status-col-width", NULL };
135static struct optname incr_search_optname = { "incsearch",       NULL };
136static struct optname use_color_optname = { "use-color",         NULL };
137#if LESSTEST
138static struct optname ttyin_name_optname = { "tty",              NULL };
139static 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 */
155static 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
572init_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 *
597findopt(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
616is_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 *
635findopt_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