1/*
2 * Copyright (C) 1984-2009 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 about less, or for information on how to
8 * contact the author, see the README file.
9 */
10
11
12/*
13 * Process command line options.
14 *
15 * Each option is a single letter which controls a program variable.
16 * The options have defaults which may be changed via
17 * the command line option, toggled via the "-" command,
18 * or queried via the "_" command.
19 */
20
21#include "less.h"
22#include "option.h"
23
24static struct loption *pendopt;
25public int plusoption = FALSE;
26
27static char *propt();
28static char *optstring();
29static int flip_triple();
30
31extern int screen_trashed;
32extern int less_is_more;
33extern int quit_at_eof;
34extern char *every_first_cmd;
35
36/*
37 * Scan an argument (either from the command line or from the
38 * LESS environment variable) and process it.
39 */
40 public void
41scan_option(s)
42 char *s;
43{
44 register struct loption *o;
45 register int optc;
46 char *optname;
47 char *printopt;
48 char *str;
49 int set_default;
50 int lc;
51 int err;
52 PARG parg;
53
54 if (s == NULL)
55 return;
56
57 /*
58 * If we have a pending option which requires an argument,
59 * handle it now.
60 * This happens if the previous option was, for example, "-P"
61 * without a following string. In that case, the current
62 * option is simply the argument for the previous option.
63 */
64 if (pendopt != NULL)
65 {
66 switch (pendopt->otype & OTYPE)
67 {
68 case STRING:
69 (*pendopt->ofunc)(INIT, s);
70 break;
71 case NUMBER:
72 printopt = propt(pendopt->oletter);
73 *(pendopt->ovar) = getnum(&s, printopt, (int*)NULL);
74 break;
75 }
76 pendopt = NULL;
77 return;
78 }
79
80 set_default = FALSE;
81 optname = NULL;
82
83 while (*s != '\0')
84 {
85 /*
86 * Check some special cases first.
87 */
88 switch (optc = *s++)
89 {
90 case ' ':
91 case '\t':
92 case END_OPTION_STRING:
93 continue;
94 case '-':
95 /*
96 * "--" indicates an option name instead of a letter.
97 */
98 if (*s == '-')
99 {
100 optname = ++s;
101 break;
102 }
103 /*
104 * "-+" means set these options back to their defaults.
105 * (They may have been set otherwise by previous
106 * options.)
107 */
108 set_default = (*s == '+');
109 if (set_default)
110 s++;
111 continue;
112 case '+':
113 /*
114 * An option prefixed by a "+" is ungotten, so
115 * that it is interpreted as less commands
116 * processed at the start of the first input file.
117 * "++" means process the commands at the start of
118 * EVERY input file.
119 */
120 plusoption = TRUE;
121 s = optstring(s, &str, propt('+'), NULL);
122 if (*str == '+')
123 every_first_cmd = save(++str);
124 else
125 ungetsc(str);
126 continue;
127 case '0': case '1': case '2': case '3': case '4':
128 case '5': case '6': case '7': case '8': case '9':
129 /*
130 * Special "more" compatibility form "-<number>"
131 * instead of -z<number> to set the scrolling
132 * window size.
133 */
134 s--;
135 optc = 'z';
136 break;
137 case 'n':
138 if (less_is_more)
139 optc = 'z';
140 break;
141 }
142
143 /*
144 * Not a special case.
145 * Look up the option letter in the option table.
146 */
147 err = 0;
148 if (optname == NULL)
149 {
150 printopt = propt(optc);
151 lc = ASCII_IS_LOWER(optc);
152 o = findopt(optc);
153 } else
154 {
155 printopt = optname;
156 lc = ASCII_IS_LOWER(optname[0]);
157 o = findopt_name(&optname, NULL, &err);
158 s = optname;
159 optname = NULL;
160 if (*s == '\0' || *s == ' ')
161 {
162 /*
163 * The option name matches exactly.
164 */
165 ;
166 } else if (*s == '=')
167 {
168 /*
169 * The option name is followed by "=value".
170 */
171 if (o != NULL &&
172 (o->otype & OTYPE) != STRING &&
173 (o->otype & OTYPE) != NUMBER)
174 {
175 parg.p_string = printopt;
176 error("The %s option should not be followed by =",
177 &parg);
178 quit(QUIT_ERROR);
179 }
180 s++;
181 } else
182 {
183 /*
184 * The specified name is longer than the
185 * real option name.
186 */
187 o = NULL;
188 }
189 }
190 if (o == NULL)
191 {
192 parg.p_string = printopt;
193 if (err == OPT_AMBIG)
194 error("%s is an ambiguous abbreviation (\"less --help\" for help)",
195 &parg);
196 else
197 error("There is no %s option (\"less --help\" for help)",
198 &parg);
199 quit(QUIT_ERROR);
200 }
201
202 str = NULL;
203 switch (o->otype & OTYPE)
204 {
205 case BOOL:
206 if (set_default)
207 *(o->ovar) = o->odefault;
208 else
209 *(o->ovar) = ! o->odefault;
210 break;
211 case TRIPLE:
212 if (set_default)
213 *(o->ovar) = o->odefault;
214 else
215 *(o->ovar) = flip_triple(o->odefault, lc);
216 break;
217 case STRING:
218 if (*s == '\0')
219 {
220 /*
221 * Set pendopt and return.
222 * We will get the string next time
223 * scan_option is called.
224 */
225 pendopt = o;
226 return;
227 }
228 /*
229 * Don't do anything here.
230 * All processing of STRING options is done by
231 * the handling function.
232 */
233 while (*s == ' ')
234 s++;
235 s = optstring(s, &str, printopt, o->odesc[1]);
236 break;
237 case NUMBER:
238 if (*s == '\0')
239 {
240 pendopt = o;
241 return;
242 }
243 *(o->ovar) = getnum(&s, printopt, (int*)NULL);
244 break;
245 }
246 /*
247 * If the option has a handling function, call it.
248 */
249 if (o->ofunc != NULL)
250 (*o->ofunc)(INIT, str);
251 }
252}
253
254/*
255 * Toggle command line flags from within the program.
256 * Used by the "-" and "_" commands.
257 * how_toggle may be:
258 * OPT_NO_TOGGLE just report the current setting, without changing it.
259 * OPT_TOGGLE invert the current setting
260 * OPT_UNSET set to the default value
261 * OPT_SET set to the inverse of the default value
262 */
263 public void
264toggle_option(c, s, how_toggle)
265 int c;
266 char *s;
267 int how_toggle;
268{
269 register struct loption *o;
270 register int num;
271 int no_prompt;
272 int err;
273 PARG parg;
274
275 no_prompt = (how_toggle & OPT_NO_PROMPT);
276 how_toggle &= ~OPT_NO_PROMPT;
277
278 /*
279 * Look up the option letter in the option table.
280 */
281 o = findopt(c);
282 if (o == NULL)
283 {
284 parg.p_string = propt(c);
285 error("There is no %s option", &parg);
286 return;
287 }
288
289 if (how_toggle == OPT_TOGGLE && (o->otype & NO_TOGGLE))
290 {
291 parg.p_string = propt(c);
292 error("Cannot change the %s option", &parg);
293 return;
294 }
295
296 if (how_toggle == OPT_NO_TOGGLE && (o->otype & NO_QUERY))
297 {
298 parg.p_string = propt(c);
299 error("Cannot query the %s option", &parg);
300 return;
301 }
302
303 /*
304 * Check for something which appears to be a do_toggle
305 * (because the "-" command was used), but really is not.
306 * This could be a string option with no string, or
307 * a number option with no number.
308 */
309 switch (o->otype & OTYPE)
310 {
311 case STRING:
312 case NUMBER:
313 if (how_toggle == OPT_TOGGLE && *s == '\0')
314 how_toggle = OPT_NO_TOGGLE;
315 break;
316 }
317
318#if HILITE_SEARCH
319 if (how_toggle != OPT_NO_TOGGLE && (o->otype & HL_REPAINT))
320 repaint_hilite(0);
321#endif
322
323 /*
324 * Now actually toggle (change) the variable.
325 */
326 if (how_toggle != OPT_NO_TOGGLE)
327 {
328 switch (o->otype & OTYPE)
329 {
330 case BOOL:
331 /*
332 * Boolean.
333 */
334 switch (how_toggle)
335 {
336 case OPT_TOGGLE:
337 *(o->ovar) = ! *(o->ovar);
338 break;
339 case OPT_UNSET:
340 *(o->ovar) = o->odefault;
341 break;
342 case OPT_SET:
343 *(o->ovar) = ! o->odefault;
344 break;
345 }
346 break;
347 case TRIPLE:
348 /*
349 * Triple:
350 * If user gave the lower case letter, then switch
351 * to 1 unless already 1, in which case make it 0.
352 * If user gave the upper case letter, then switch
353 * to 2 unless already 2, in which case make it 0.
354 */
355 switch (how_toggle)
356 {
357 case OPT_TOGGLE:
358 *(o->ovar) = flip_triple(*(o->ovar),
359 ASCII_IS_LOWER(c));
360 break;
361 case OPT_UNSET:
362 *(o->ovar) = o->odefault;
363 break;
364 case OPT_SET:
365 *(o->ovar) = flip_triple(o->odefault,
366 ASCII_IS_LOWER(c));
367 break;
368 }
369 break;
370 case STRING:
371 /*
372 * String: don't do anything here.
373 * The handling function will do everything.
374 */
375 switch (how_toggle)
376 {
377 case OPT_SET:
378 case OPT_UNSET:
379 error("Cannot use \"-+\" or \"--\" for a string option",
380 NULL_PARG);
381 return;
382 }
383 break;
384 case NUMBER:
385 /*
386 * Number: set the variable to the given number.
387 */
388 switch (how_toggle)
389 {
390 case OPT_TOGGLE:
391 num = getnum(&s, NULL, &err);
392 if (!err)
393 *(o->ovar) = num;
394 break;
395 case OPT_UNSET:
396 *(o->ovar) = o->odefault;
397 break;
398 case OPT_SET:
399 error("Can't use \"-!\" for a numeric option",
400 NULL_PARG);
401 return;
402 }
403 break;
404 }
405 }
406
407 /*
408 * Call the handling function for any special action
409 * specific to this option.
410 */
411 if (o->ofunc != NULL)
412 (*o->ofunc)((how_toggle==OPT_NO_TOGGLE) ? QUERY : TOGGLE, s);
413
414#if HILITE_SEARCH
415 if (how_toggle != OPT_NO_TOGGLE && (o->otype & HL_REPAINT))
416 chg_hilite();
417#endif
418
419 if (!no_prompt)
420 {
421 /*
422 * Print a message describing the new setting.
423 */
424 switch (o->otype & OTYPE)
425 {
426 case BOOL:
427 case TRIPLE:
428 /*
429 * Print the odesc message.
430 */
431 error(o->odesc[*(o->ovar)], NULL_PARG);
432 break;
433 case NUMBER:
434 /*
435 * The message is in odesc[1] and has a %d for
436 * the value of the variable.
437 */
438 parg.p_int = *(o->ovar);
439 error(o->odesc[1], &parg);
440 break;
441 case STRING:
442 /*
443 * Message was already printed by the handling function.
444 */
445 break;
446 }
447 }
448
449 if (how_toggle != OPT_NO_TOGGLE && (o->otype & REPAINT))
450 screen_trashed = TRUE;
451}
452
453/*
454 * "Toggle" a triple-valued option.
455 */
456 static int
457flip_triple(val, lc)
458 int val;
459 int lc;
460{
461 if (lc)
462 return ((val == OPT_ON) ? OPT_OFF : OPT_ON);
463 else
464 return ((val == OPT_ONPLUS) ? OPT_OFF : OPT_ONPLUS);
465}
466
467/*
468 * Return a string suitable for printing as the "name" of an option.
469 * For example, if the option letter is 'x', just return "-x".
470 */
471 static char *
472propt(c)
473 int c;
474{
475 static char buf[8];
476
477 sprintf(buf, "-%s", prchar(c));
478 return (buf);
479}
480
481/*
482 * Determine if an option is a single character option (BOOL or TRIPLE),
483 * or if it a multi-character option (NUMBER).
484 */
485 public int
486single_char_option(c)
487 int c;
488{
489 register struct loption *o;
490
491 o = findopt(c);
492 if (o == NULL)
493 return (TRUE);
494 return ((o->otype & (BOOL|TRIPLE|NOVAR|NO_TOGGLE)) != 0);
495}
496
497/*
498 * Return the prompt to be used for a given option letter.
499 * Only string and number valued options have prompts.
500 */
501 public char *
502opt_prompt(c)
503 int c;
504{
505 register struct loption *o;
506
507 o = findopt(c);
508 if (o == NULL || (o->otype & (STRING|NUMBER)) == 0)
509 return (NULL);
510 return (o->odesc[0]);
511}
512
513/*
514 * Return whether or not there is a string option pending;
515 * that is, if the previous option was a string-valued option letter
516 * (like -P) without a following string.
517 * In that case, the current option is taken to be the string for
518 * the previous option.
519 */
520 public int
521isoptpending()
522{
523 return (pendopt != NULL);
524}
525
526/*
527 * Print error message about missing string.
528 */
529 static void
530nostring(printopt)
531 char *printopt;
532{
533 PARG parg;
534 parg.p_string = printopt;
535 error("Value is required after %s", &parg);
536}
537
538/*
539 * Print error message if a STRING type option is not followed by a string.
540 */
541 public void
542nopendopt()
543{
544 nostring(propt(pendopt->oletter));
545}
546
547/*
548 * Scan to end of string or to an END_OPTION_STRING character.
549 * In the latter case, replace the char with a null char.
550 * Return a pointer to the remainder of the string, if any.
551 */
552 static char *
553optstring(s, p_str, printopt, validchars)
554 char *s;
555 char **p_str;
556 char *printopt;
557 char *validchars;
558{
559 register char *p;
560
561 if (*s == '\0')
562 {
563 nostring(printopt);
564 quit(QUIT_ERROR);
565 }
566 *p_str = s;
567 for (p = s; *p != '\0'; p++)
568 {
569 if (*p == END_OPTION_STRING ||
570 (validchars != NULL && strchr(validchars, *p) == NULL))
571 {
572 switch (*p)
573 {
574 case END_OPTION_STRING:
575 case ' ': case '\t': case '-':
576 /* Replace the char with a null to terminate string. */
577 *p++ = '\0';
578 break;
579 default:
580 /* Cannot replace char; make a copy of the string. */
581 *p_str = (char *) ecalloc(p-s+1, sizeof(char));
582 strncpy(*p_str, s, p-s);
583 (*p_str)[p-s] = '\0';
584 break;
585 }
586 break;
587 }
588 }
589 return (p);
590}
591
592/*
593 */
594 static int
595num_error(printopt, errp)
596 char *printopt;
597 int *errp;
598{
599 PARG parg;
600
601 if (errp != NULL)
602 {
603 *errp = TRUE;
604 return (-1);
605 }
606 if (printopt != NULL)
607 {
608 parg.p_string = printopt;
609 error("Number is required after %s", &parg);
610 }
611 quit(QUIT_ERROR);
612 /* NOTREACHED */
613 return (-1);
614}
615
616/*
617 * Translate a string into a number.
618 * Like atoi(), but takes a pointer to a char *, and updates
619 * the char * to point after the translated number.
620 */
621 public int
622getnum(sp, printopt, errp)
623 char **sp;
624 char *printopt;
625 int *errp;
626{
627 register char *s;
628 register int n;
629 register int neg;
630
631 s = skipsp(*sp);
632 neg = FALSE;
633 if (*s == '-')
634 {
635 neg = TRUE;
636 s++;
637 }
638 if (*s < '0' || *s > '9')
639 return (num_error(printopt, errp));
640
641 n = 0;
642 while (*s >= '0' && *s <= '9')
643 n = 10 * n + *s++ - '0';
644 *sp = s;
645 if (errp != NULL)
646 *errp = FALSE;
647 if (neg)
648 n = -n;
649 return (n);
650}
651
652/*
653 * Translate a string into a fraction, represented by the part of a
654 * number which would follow a decimal point.
655 * The value of the fraction is returned as parts per NUM_FRAC_DENOM.
656 * That is, if "n" is returned, the fraction intended is n/NUM_FRAC_DENOM.
657 */
658 public long
659getfraction(sp, printopt, errp)
660 char **sp;
661 char *printopt;
662 int *errp;
663{
664 register char *s;
665 long frac = 0;
666 int fraclen = 0;
667
668 s = skipsp(*sp);
669 if (*s < '0' || *s > '9')
670 return (num_error(printopt, errp));
671
672 for ( ; *s >= '0' && *s <= '9'; s++)
673 {
674 frac = (frac * 10) + (*s - '0');
675 fraclen++;
676 }
677 if (fraclen > NUM_LOG_FRAC_DENOM)
678 while (fraclen-- > NUM_LOG_FRAC_DENOM)
679 frac /= 10;
680 else
681 while (fraclen++ < NUM_LOG_FRAC_DENOM)
682 frac *= 10;
683 *sp = s;
684 if (errp != NULL)
685 *errp = FALSE;
686 return (frac);
687}
688
689
690/*
691 * Get the value of the -e flag.
692 */
693 public int
694get_quit_at_eof()
695{
696 if (!less_is_more)
697 return quit_at_eof;
698 /* When less_is_more is set, the -e flag semantics are different. */
699 return quit_at_eof ? OPT_ON : OPT_ONPLUS;
700}