1 /*
2 * Copyright (C) 1984-2015 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 * Process command line options.
13 *
14 * Each option is a single letter which controls a program variable.
15 * The options have defaults which may be changed via
16 * the command line option, toggled via the "-" command,
17 * or queried via the "_" command.
18 */
19
20 #include "less.h"
21 #include "option.h"
22
23 static struct loption *pendopt;
24 public int plusoption = FALSE;
25
26 static char *optstring();
27 static int flip_triple();
28
29 extern int screen_trashed;
30 extern int less_is_more;
31 extern int quit_at_eof;
32 extern char *every_first_cmd;
33 extern int opt_use_backslash;
34
35 /*
36 * Return a printable description of an option.
37 */
38 static char *
opt_desc(o)39 opt_desc(o)
40 struct loption *o;
41 {
42 static char buf[OPTNAME_MAX + 10];
43 if (o->oletter == OLETTER_NONE)
44 SNPRINTF1(buf, sizeof(buf), "--%s", o->onames->oname);
45 else
46 SNPRINTF2(buf, sizeof(buf), "-%c (--%s)", o->oletter, o->onames->oname);
47 return (buf);
48 }
49
50 /*
51 * Return a string suitable for printing as the "name" of an option.
52 * For example, if the option letter is 'x', just return "-x".
53 */
54 public char *
propt(c)55 propt(c)
56 int c;
57 {
58 static char buf[8];
59
60 sprintf(buf, "-%s", prchar(c));
61 return (buf);
62 }
63
64 /*
65 * Scan an argument (either from the command line or from the
66 * LESS environment variable) and process it.
67 */
68 public void
scan_option(s)69 scan_option(s)
70 char *s;
71 {
72 register struct loption *o;
73 register int optc;
74 char *optname;
75 char *printopt;
76 char *str;
77 int set_default;
78 int lc;
79 int err;
80 PARG parg;
81
82 if (s == NULL)
83 return;
84
85 /*
86 * If we have a pending option which requires an argument,
87 * handle it now.
88 * This happens if the previous option was, for example, "-P"
89 * without a following string. In that case, the current
90 * option is simply the argument for the previous option.
91 */
92 if (pendopt != NULL)
93 {
94 switch (pendopt->otype & OTYPE)
95 {
96 case STRING:
97 (*pendopt->ofunc)(INIT, s);
98 break;
99 case NUMBER:
100 printopt = opt_desc(pendopt);
101 *(pendopt->ovar) = getnum(&s, printopt, (int*)NULL);
102 break;
103 }
104 pendopt = NULL;
105 return;
106 }
107
108 set_default = FALSE;
109 optname = NULL;
110
111 while (*s != '\0')
112 {
113 /*
114 * Check some special cases first.
115 */
116 switch (optc = *s++)
117 {
118 case ' ':
119 case '\t':
120 case END_OPTION_STRING:
121 continue;
122 case '-':
123 /*
124 * "--" indicates an option name instead of a letter.
125 */
126 if (*s == '-')
127 {
128 optname = ++s;
129 break;
130 }
131 /*
132 * "-+" means set these options back to their defaults.
133 * (They may have been set otherwise by previous
134 * options.)
135 */
136 set_default = (*s == '+');
137 if (set_default)
138 s++;
139 continue;
140 case '+':
141 /*
142 * An option prefixed by a "+" is ungotten, so
143 * that it is interpreted as less commands
144 * processed at the start of the first input file.
145 * "++" means process the commands at the start of
146 * EVERY input file.
147 */
148 plusoption = TRUE;
149 s = optstring(s, &str, propt('+'), NULL);
150 if (s == NULL)
151 return;
152 if (*str == '+')
153 every_first_cmd = save(str+1);
154 else
155 {
156 ungetcc(CHAR_END_COMMAND);
157 ungetsc(str);
158 }
159 free(str);
160 continue;
161 case '0': case '1': case '2': case '3': case '4':
162 case '5': case '6': case '7': case '8': case '9':
163 /*
164 * Special "more" compatibility form "-<number>"
165 * instead of -z<number> to set the scrolling
166 * window size.
167 */
168 s--;
169 optc = 'z';
170 break;
171 case 'n':
172 if (less_is_more)
173 optc = 'z';
174 break;
175 }
176
177 /*
178 * Not a special case.
179 * Look up the option letter in the option table.
180 */
181 err = 0;
182 if (optname == NULL)
183 {
184 printopt = propt(optc);
185 lc = ASCII_IS_LOWER(optc);
186 o = findopt(optc);
187 } else
188 {
189 printopt = optname;
190 lc = ASCII_IS_LOWER(optname[0]);
191 o = findopt_name(&optname, NULL, &err);
192 s = optname;
193 optname = NULL;
194 if (*s == '\0' || *s == ' ')
195 {
196 /*
197 * The option name matches exactly.
198 */
199 ;
200 } else if (*s == '=')
201 {
202 /*
203 * The option name is followed by "=value".
204 */
205 if (o != NULL &&
206 (o->otype & OTYPE) != STRING &&
207 (o->otype & OTYPE) != NUMBER)
208 {
209 parg.p_string = printopt;
210 error("The %s option should not be followed by =",
211 &parg);
212 return;
213 }
214 s++;
215 } else
216 {
217 /*
218 * The specified name is longer than the
219 * real option name.
220 */
221 o = NULL;
222 }
223 }
224 if (o == NULL)
225 {
226 parg.p_string = printopt;
227 if (err == OPT_AMBIG)
228 error("%s is an ambiguous abbreviation (\"less --help\" for help)",
229 &parg);
230 else
231 error("There is no %s option (\"less --help\" for help)",
232 &parg);
233 return;
234 }
235
236 str = NULL;
237 switch (o->otype & OTYPE)
238 {
239 case BOOL:
240 if (set_default)
241 *(o->ovar) = o->odefault;
242 else
243 *(o->ovar) = ! o->odefault;
244 break;
245 case TRIPLE:
246 if (set_default)
247 *(o->ovar) = o->odefault;
248 else
249 *(o->ovar) = flip_triple(o->odefault, lc);
250 break;
251 case STRING:
252 if (*s == '\0')
253 {
254 /*
255 * Set pendopt and return.
256 * We will get the string next time
257 * scan_option is called.
258 */
259 pendopt = o;
260 return;
261 }
262 /*
263 * Don't do anything here.
264 * All processing of STRING options is done by
265 * the handling function.
266 */
267 while (*s == ' ')
268 s++;
269 s = optstring(s, &str, printopt, o->odesc[1]);
270 if (s == NULL)
271 return;
272 break;
273 case NUMBER:
274 if (*s == '\0')
275 {
276 pendopt = o;
277 return;
278 }
279 *(o->ovar) = getnum(&s, printopt, (int*)NULL);
280 break;
281 }
282 /*
283 * If the option has a handling function, call it.
284 */
285 if (o->ofunc != NULL)
286 (*o->ofunc)(INIT, str);
287 if (str != NULL)
288 free(str);
289 }
290 }
291
292 /*
293 * Toggle command line flags from within the program.
294 * Used by the "-" and "_" commands.
295 * how_toggle may be:
296 * OPT_NO_TOGGLE just report the current setting, without changing it.
297 * OPT_TOGGLE invert the current setting
298 * OPT_UNSET set to the default value
299 * OPT_SET set to the inverse of the default value
300 */
301 public void
toggle_option(o,lower,s,how_toggle)302 toggle_option(o, lower, s, how_toggle)
303 struct loption *o;
304 int lower;
305 char *s;
306 int how_toggle;
307 {
308 register int num;
309 int no_prompt;
310 int err;
311 PARG parg;
312
313 no_prompt = (how_toggle & OPT_NO_PROMPT);
314 how_toggle &= ~OPT_NO_PROMPT;
315
316 if (o == NULL)
317 {
318 error("No such option", NULL_PARG);
319 return;
320 }
321
322 if (how_toggle == OPT_TOGGLE && (o->otype & NO_TOGGLE))
323 {
324 parg.p_string = opt_desc(o);
325 error("Cannot change the %s option", &parg);
326 return;
327 }
328
329 if (how_toggle == OPT_NO_TOGGLE && (o->otype & NO_QUERY))
330 {
331 parg.p_string = opt_desc(o);
332 error("Cannot query the %s option", &parg);
333 return;
334 }
335
336 /*
337 * Check for something which appears to be a do_toggle
338 * (because the "-" command was used), but really is not.
339 * This could be a string option with no string, or
340 * a number option with no number.
341 */
342 switch (o->otype & OTYPE)
343 {
344 case STRING:
345 case NUMBER:
346 if (how_toggle == OPT_TOGGLE && *s == '\0')
347 how_toggle = OPT_NO_TOGGLE;
348 break;
349 }
350
351 #if HILITE_SEARCH
352 if (how_toggle != OPT_NO_TOGGLE && (o->otype & HL_REPAINT))
353 repaint_hilite(0);
354 #endif
355
356 /*
357 * Now actually toggle (change) the variable.
358 */
359 if (how_toggle != OPT_NO_TOGGLE)
360 {
361 switch (o->otype & OTYPE)
362 {
363 case BOOL:
364 /*
365 * Boolean.
366 */
367 switch (how_toggle)
368 {
369 case OPT_TOGGLE:
370 *(o->ovar) = ! *(o->ovar);
371 break;
372 case OPT_UNSET:
373 *(o->ovar) = o->odefault;
374 break;
375 case OPT_SET:
376 *(o->ovar) = ! o->odefault;
377 break;
378 }
379 break;
380 case TRIPLE:
381 /*
382 * Triple:
383 * If user gave the lower case letter, then switch
384 * to 1 unless already 1, in which case make it 0.
385 * If user gave the upper case letter, then switch
386 * to 2 unless already 2, in which case make it 0.
387 */
388 switch (how_toggle)
389 {
390 case OPT_TOGGLE:
391 *(o->ovar) = flip_triple(*(o->ovar), lower);
392 break;
393 case OPT_UNSET:
394 *(o->ovar) = o->odefault;
395 break;
396 case OPT_SET:
397 *(o->ovar) = flip_triple(o->odefault, lower);
398 break;
399 }
400 break;
401 case STRING:
402 /*
403 * String: don't do anything here.
404 * The handling function will do everything.
405 */
406 switch (how_toggle)
407 {
408 case OPT_SET:
409 case OPT_UNSET:
410 error("Cannot use \"-+\" or \"--\" for a string option",
411 NULL_PARG);
412 return;
413 }
414 break;
415 case NUMBER:
416 /*
417 * Number: set the variable to the given number.
418 */
419 switch (how_toggle)
420 {
421 case OPT_TOGGLE:
422 num = getnum(&s, NULL, &err);
423 if (!err)
424 *(o->ovar) = num;
425 break;
426 case OPT_UNSET:
427 *(o->ovar) = o->odefault;
428 break;
429 case OPT_SET:
430 error("Can't use \"-!\" for a numeric option",
431 NULL_PARG);
432 return;
433 }
434 break;
435 }
436 }
437
438 /*
439 * Call the handling function for any special action
440 * specific to this option.
441 */
442 if (o->ofunc != NULL)
443 (*o->ofunc)((how_toggle==OPT_NO_TOGGLE) ? QUERY : TOGGLE, s);
444
445 #if HILITE_SEARCH
446 if (how_toggle != OPT_NO_TOGGLE && (o->otype & HL_REPAINT))
447 chg_hilite();
448 #endif
449
450 if (!no_prompt)
451 {
452 /*
453 * Print a message describing the new setting.
454 */
455 switch (o->otype & OTYPE)
456 {
457 case BOOL:
458 case TRIPLE:
459 /*
460 * Print the odesc message.
461 */
462 error(o->odesc[*(o->ovar)], NULL_PARG);
463 break;
464 case NUMBER:
465 /*
466 * The message is in odesc[1] and has a %d for
467 * the value of the variable.
468 */
469 parg.p_int = *(o->ovar);
470 error(o->odesc[1], &parg);
471 break;
472 case STRING:
473 /*
474 * Message was already printed by the handling function.
475 */
476 break;
477 }
478 }
479
480 if (how_toggle != OPT_NO_TOGGLE && (o->otype & REPAINT))
481 screen_trashed = TRUE;
482 }
483
484 /*
485 * "Toggle" a triple-valued option.
486 */
487 static int
flip_triple(val,lc)488 flip_triple(val, lc)
489 int val;
490 int lc;
491 {
492 if (lc)
493 return ((val == OPT_ON) ? OPT_OFF : OPT_ON);
494 else
495 return ((val == OPT_ONPLUS) ? OPT_OFF : OPT_ONPLUS);
496 }
497
498 /*
499 * Determine if an option takes a parameter.
500 */
501 public int
opt_has_param(o)502 opt_has_param(o)
503 struct loption *o;
504 {
505 if (o == NULL)
506 return (0);
507 if (o->otype & (BOOL|TRIPLE|NOVAR|NO_TOGGLE))
508 return (0);
509 return (1);
510 }
511
512 /*
513 * Return the prompt to be used for a given option letter.
514 * Only string and number valued options have prompts.
515 */
516 public char *
opt_prompt(o)517 opt_prompt(o)
518 struct loption *o;
519 {
520 if (o == NULL || (o->otype & (STRING|NUMBER)) == 0)
521 return ("?");
522 return (o->odesc[0]);
523 }
524
525 /*
526 * Return whether or not there is a string option pending;
527 * that is, if the previous option was a string-valued option letter
528 * (like -P) without a following string.
529 * In that case, the current option is taken to be the string for
530 * the previous option.
531 */
532 public int
isoptpending()533 isoptpending()
534 {
535 return (pendopt != NULL);
536 }
537
538 /*
539 * Print error message about missing string.
540 */
541 static void
nostring(printopt)542 nostring(printopt)
543 char *printopt;
544 {
545 PARG parg;
546 parg.p_string = printopt;
547 error("Value is required after %s", &parg);
548 }
549
550 /*
551 * Print error message if a STRING type option is not followed by a string.
552 */
553 public void
nopendopt()554 nopendopt()
555 {
556 nostring(opt_desc(pendopt));
557 }
558
559 /*
560 * Scan to end of string or to an END_OPTION_STRING character.
561 * In the latter case, replace the char with a null char.
562 * Return a pointer to the remainder of the string, if any.
563 */
564 static char *
optstring(s,p_str,printopt,validchars)565 optstring(s, p_str, printopt, validchars)
566 char *s;
567 char **p_str;
568 char *printopt;
569 char *validchars;
570 {
571 register char *p;
572 register char *out;
573
574 if (*s == '\0')
575 {
576 nostring(printopt);
577 return (NULL);
578 }
579 /* Alloc could be more than needed, but not worth trimming. */
580 *p_str = (char *) ecalloc(strlen(s)+1, sizeof(char));
581 out = *p_str;
582
583 for (p = s; *p != '\0'; p++)
584 {
585 if (opt_use_backslash && *p == '\\' && p[1] != '\0')
586 {
587 /* Take next char literally. */
588 ++p;
589 } else
590 {
591 if (*p == END_OPTION_STRING ||
592 (validchars != NULL && strchr(validchars, *p) == NULL))
593 /* End of option string. */
594 break;
595 }
596 *out++ = *p;
597 }
598 *out = '\0';
599 return (p);
600 }
601
602 /*
603 */
604 static int
num_error(printopt,errp)605 num_error(printopt, errp)
606 char *printopt;
607 int *errp;
608 {
609 PARG parg;
610
611 if (errp != NULL)
612 {
613 *errp = TRUE;
614 return (-1);
615 }
616 if (printopt != NULL)
617 {
618 parg.p_string = printopt;
619 error("Number is required after %s", &parg);
620 }
621 return (-1);
622 }
623
624 /*
625 * Translate a string into a number.
626 * Like atoi(), but takes a pointer to a char *, and updates
627 * the char * to point after the translated number.
628 */
629 public int
getnum(sp,printopt,errp)630 getnum(sp, printopt, errp)
631 char **sp;
632 char *printopt;
633 int *errp;
634 {
635 register char *s;
636 register int n;
637 register int neg;
638
639 s = skipsp(*sp);
640 neg = FALSE;
641 if (*s == '-')
642 {
643 neg = TRUE;
644 s++;
645 }
646 if (*s < '0' || *s > '9')
647 return (num_error(printopt, errp));
648
649 n = 0;
650 while (*s >= '0' && *s <= '9')
651 n = 10 * n + *s++ - '0';
652 *sp = s;
653 if (errp != NULL)
654 *errp = FALSE;
655 if (neg)
656 n = -n;
657 return (n);
658 }
659
660 /*
661 * Translate a string into a fraction, represented by the part of a
662 * number which would follow a decimal point.
663 * The value of the fraction is returned as parts per NUM_FRAC_DENOM.
664 * That is, if "n" is returned, the fraction intended is n/NUM_FRAC_DENOM.
665 */
666 public long
getfraction(sp,printopt,errp)667 getfraction(sp, printopt, errp)
668 char **sp;
669 char *printopt;
670 int *errp;
671 {
672 register char *s;
673 long frac = 0;
674 int fraclen = 0;
675
676 s = skipsp(*sp);
677 if (*s < '0' || *s > '9')
678 return (num_error(printopt, errp));
679
680 for ( ; *s >= '0' && *s <= '9'; s++)
681 {
682 frac = (frac * 10) + (*s - '0');
683 fraclen++;
684 }
685 if (fraclen > NUM_LOG_FRAC_DENOM)
686 while (fraclen-- > NUM_LOG_FRAC_DENOM)
687 frac /= 10;
688 else
689 while (fraclen++ < NUM_LOG_FRAC_DENOM)
690 frac *= 10;
691 *sp = s;
692 if (errp != NULL)
693 *errp = FALSE;
694 return (frac);
695 }
696
697
698 /*
699 * Get the value of the -e flag.
700 */
701 public int
get_quit_at_eof()702 get_quit_at_eof()
703 {
704 if (!less_is_more)
705 return quit_at_eof;
706 /* When less_is_more is set, the -e flag semantics are different. */
707 return quit_at_eof ? OPT_ONPLUS : OPT_ON;
708 }
709