1 /* $NetBSD: prompt.c,v 1.4 2013/09/04 19:44:21 tron Exp $ */
2
3 /*
4 * Copyright (C) 1984-2012 Mark Nudelman
5 *
6 * You may distribute under the terms of either the GNU General Public
7 * License or the Less License, as specified in the README file.
8 *
9 * For more information, see the README file.
10 */
11
12
13 /*
14 * Prompting and other messages.
15 * There are three flavors of prompts, SHORT, MEDIUM and LONG,
16 * selected by the -m/-M options.
17 * There is also the "equals message", printed by the = command.
18 * A prompt is a message composed of various pieces, such as the
19 * name of the file being viewed, the percentage into the file, etc.
20 */
21
22 #include "less.h"
23 #include "position.h"
24
25 extern int pr_type;
26 extern int new_file;
27 extern int sc_width;
28 extern int so_s_width, so_e_width;
29 extern int linenums;
30 extern int hshift;
31 extern int sc_height;
32 extern int jump_sline;
33 extern int less_is_more;
34 extern IFILE curr_ifile;
35 #if EDITOR
36 extern char *editor;
37 extern char *editproto;
38 #endif
39
40 /*
41 * Prototypes for the three flavors of prompts.
42 * These strings are expanded by pr_expand().
43 */
44 static constant char s_proto[] =
45 "?n?f%f .?m(%T %i of %m) ..?e(END) ?x- Next\\: %x..%t";
46 static constant char m_proto[] =
47 "?n?f%f .?m(%T %i of %m) ..?e(END) ?x- Next\\: %x.:?pB%pB\\%:byte %bB?s/%s...%t";
48 static constant char M_proto[] =
49 "?f%f .?n?m(%T %i of %m) ..?ltlines %lt-%lb?L/%L. :byte %bB?s/%s. .?e(END) ?x- Next\\: %x.:?pB%pB\\%..%t";
50 static constant char e_proto[] =
51 "?f%f .?m(%T %i of %m) .?ltlines %lt-%lb?L/%L. .byte %bB?s/%s. ?e(END) :?pB%pB\\%..%t";
52 static constant char h_proto[] =
53 "HELP -- ?eEND -- Press g to see it again:Press RETURN for more., or q when done";
54 static constant char w_proto[] =
55 "Waiting for data";
56 static constant char more_proto[] =
57 "--More--(?eEND ?x- Next\\: %x.:?pB%pB\\%:byte %bB?s/%s...%t)";
58
59 public char constant *prproto[3];
60 public char constant *eqproto = e_proto;
61 public char constant *hproto = h_proto;
62 public char constant *wproto = w_proto;
63
64 static char message[PROMPT_SIZE];
65 static char *mp;
66
67 static void ap_pos __P((POSITION));
68 static void ap_int __P((int));
69 static void ap_str __P((char *));
70 static void ap_char __P((int));
71 static void ap_quest __P((void));
72 static POSITION curr_byte __P((int));
73 static int cond __P((int, int));
74 static void protochar __P((int, int, int));
75 static const char *skipcond __P((const char *));
76 static const char *wherechar __P((const char *, int *));
77
78 /*
79 * Initialize the prompt prototype strings.
80 */
81 public void
init_prompt()82 init_prompt()
83 {
84 prproto[0] = save(s_proto);
85 prproto[1] = save(less_is_more ? more_proto : m_proto);
86 prproto[2] = save(M_proto);
87 eqproto = save(e_proto);
88 hproto = save(h_proto);
89 wproto = save(w_proto);
90 }
91
92 /*
93 * Append a string to the end of the message.
94 */
95 static void
ap_str(s)96 ap_str(s)
97 char *s;
98 {
99 int len;
100
101 len = strlen(s);
102 if (mp + len >= message + PROMPT_SIZE)
103 len = message + PROMPT_SIZE - mp - 1;
104 strncpy(mp, s, len);
105 mp += len;
106 *mp = '\0';
107 }
108
109 /*
110 * Append a character to the end of the message.
111 */
112 static void
ap_char(i)113 ap_char(i)
114 int i;
115 {
116 char buf[2];
117 char c = (char)i;
118
119 buf[0] = c;
120 buf[1] = '\0';
121 ap_str(buf);
122 }
123
124 /*
125 * Append a POSITION (as a decimal integer) to the end of the message.
126 */
127 static void
ap_pos(pos)128 ap_pos(pos)
129 POSITION pos;
130 {
131 char buf[INT_STRLEN_BOUND(pos) + 2];
132
133 postoa(pos, buf);
134 ap_str(buf);
135 }
136
137 /*
138 * Append a line number to the end of the message.
139 */
140 static void
ap_linenum(linenum)141 ap_linenum(linenum)
142 LINENUM linenum;
143 {
144 char buf[INT_STRLEN_BOUND(linenum) + 2];
145
146 linenumtoa(linenum, buf);
147 ap_str(buf);
148 }
149
150 /*
151 * Append an integer to the end of the message.
152 */
153 static void
ap_int(num)154 ap_int(num)
155 int num;
156 {
157 char buf[INT_STRLEN_BOUND(num) + 2];
158
159 inttoa(num, buf);
160 ap_str(buf);
161 }
162
163 /*
164 * Append a question mark to the end of the message.
165 */
166 static void
ap_quest()167 ap_quest()
168 {
169 ap_str("?");
170 }
171
172 /*
173 * Return the "current" byte offset in the file.
174 */
175 static POSITION
curr_byte(where)176 curr_byte(where)
177 int where;
178 {
179 POSITION pos;
180
181 pos = position(where);
182 while (pos == NULL_POSITION && where >= 0 && where < sc_height-1)
183 pos = position(++where);
184 if (pos == NULL_POSITION)
185 pos = ch_length();
186 return (pos);
187 }
188
189 /*
190 * Return the value of a prototype conditional.
191 * A prototype string may include conditionals which consist of a
192 * question mark followed by a single letter.
193 * Here we decode that letter and return the appropriate boolean value.
194 */
195 static int
cond(c,where)196 cond(c, where)
197 char c;
198 int where;
199 {
200 POSITION len;
201
202 switch (c)
203 {
204 case 'a': /* Anything in the message yet? */
205 return (mp > message);
206 case 'b': /* Current byte offset known? */
207 return (curr_byte(where) != NULL_POSITION);
208 case 'c':
209 return (hshift != 0);
210 case 'e': /* At end of file? */
211 return (eof_displayed());
212 case 'f': /* Filename known? */
213 return (strcmp(get_filename(curr_ifile), "-") != 0);
214 case 'l': /* Line number known? */
215 case 'd': /* Same as l */
216 return (linenums);
217 case 'L': /* Final line number known? */
218 case 'D': /* Final page number known? */
219 return (linenums && ch_length() != NULL_POSITION);
220 case 'm': /* More than one file? */
221 #if TAGS
222 return (ntags() ? (ntags() > 1) : (nifile() > 1));
223 #else
224 return (nifile() > 1);
225 #endif
226 case 'n': /* First prompt in a new file? */
227 #if TAGS
228 return (ntags() ? 1 : new_file);
229 #else
230 return (new_file);
231 #endif
232 case 'p': /* Percent into file (bytes) known? */
233 return (curr_byte(where) != NULL_POSITION &&
234 ch_length() > 0);
235 case 'P': /* Percent into file (lines) known? */
236 return (currline(where) != 0 &&
237 (len = ch_length()) > 0 &&
238 find_linenum(len) != 0);
239 case 's': /* Size of file known? */
240 case 'B':
241 return (ch_length() != NULL_POSITION);
242 case 'x': /* Is there a "next" file? */
243 #if TAGS
244 if (ntags())
245 return (0);
246 #endif
247 return (next_ifile(curr_ifile) != NULL_IFILE);
248 }
249 return (0);
250 }
251
252 /*
253 * Decode a "percent" prototype character.
254 * A prototype string may include various "percent" escapes;
255 * that is, a percent sign followed by a single letter.
256 * Here we decode that letter and take the appropriate action,
257 * usually by appending something to the message being built.
258 */
259 static void
protochar(c,where,iseditproto)260 protochar(c, where, iseditproto)
261 int c;
262 int where;
263 int iseditproto;
264 {
265 POSITION pos;
266 POSITION len;
267 int n;
268 LINENUM linenum;
269 LINENUM last_linenum;
270 IFILE h;
271
272 #undef PAGE_NUM
273 #define PAGE_NUM(linenum) ((((linenum) - 1) / (sc_height - 1)) + 1)
274
275 switch (c)
276 {
277 case 'b': /* Current byte offset */
278 pos = curr_byte(where);
279 if (pos != NULL_POSITION)
280 ap_pos(pos);
281 else
282 ap_quest();
283 break;
284 case 'c':
285 ap_int(hshift);
286 break;
287 case 'd': /* Current page number */
288 linenum = currline(where);
289 if (linenum > 0 && sc_height > 1)
290 ap_linenum(PAGE_NUM(linenum));
291 else
292 ap_quest();
293 break;
294 case 'D': /* Final page number */
295 /* Find the page number of the last byte in the file (len-1). */
296 len = ch_length();
297 if (len == NULL_POSITION)
298 ap_quest();
299 else if (len == 0)
300 /* An empty file has no pages. */
301 ap_linenum(0);
302 else
303 {
304 linenum = find_linenum(len - 1);
305 if (linenum <= 0)
306 ap_quest();
307 else
308 ap_linenum(PAGE_NUM(linenum));
309 }
310 break;
311 #if EDITOR
312 case 'E': /* Editor name */
313 ap_str(editor);
314 break;
315 #endif
316 case 'f': /* File name */
317 ap_str(get_filename(curr_ifile));
318 break;
319 case 'F': /* Last component of file name */
320 ap_str(last_component(get_filename(curr_ifile)));
321 break;
322 case 'i': /* Index into list of files */
323 #if TAGS
324 if (ntags())
325 ap_int(curr_tag());
326 else
327 #endif
328 ap_int(get_index(curr_ifile));
329 break;
330 case 'l': /* Current line number */
331 linenum = currline(where);
332 if (linenum != 0)
333 ap_linenum(linenum);
334 else
335 ap_quest();
336 break;
337 case 'L': /* Final line number */
338 len = ch_length();
339 if (len == NULL_POSITION || len == ch_zero() ||
340 (linenum = find_linenum(len)) <= 0)
341 ap_quest();
342 else
343 ap_linenum(linenum-1);
344 break;
345 case 'm': /* Number of files */
346 #if TAGS
347 n = ntags();
348 if (n)
349 ap_int(n);
350 else
351 #endif
352 ap_int(nifile());
353 break;
354 case 'p': /* Percent into file (bytes) */
355 pos = curr_byte(where);
356 len = ch_length();
357 if (pos != NULL_POSITION && len > 0)
358 ap_int(percentage(pos,len));
359 else
360 ap_quest();
361 break;
362 case 'P': /* Percent into file (lines) */
363 linenum = currline(where);
364 if (linenum == 0 ||
365 (len = ch_length()) == NULL_POSITION || len == ch_zero() ||
366 (last_linenum = find_linenum(len)) <= 0)
367 ap_quest();
368 else
369 ap_int(percentage(linenum, last_linenum));
370 break;
371 case 's': /* Size of file */
372 case 'B':
373 len = ch_length();
374 if (len != NULL_POSITION)
375 ap_pos(len);
376 else
377 ap_quest();
378 break;
379 case 't': /* Truncate trailing spaces in the message */
380 while (mp > message && mp[-1] == ' ')
381 mp--;
382 *mp = '\0';
383 break;
384 case 'T': /* Type of list */
385 #if TAGS
386 if (ntags())
387 ap_str("tag");
388 else
389 #endif
390 ap_str("file");
391 break;
392 case 'x': /* Name of next file */
393 h = next_ifile(curr_ifile);
394 if (h != NULL_IFILE)
395 ap_str(get_filename(h));
396 else
397 ap_quest();
398 break;
399 }
400 }
401
402 /*
403 * Skip a false conditional.
404 * When a false condition is found (either a false IF or the ELSE part
405 * of a true IF), this routine scans the prototype string to decide
406 * where to resume parsing the string.
407 * We must keep track of nested IFs and skip them properly.
408 */
409 static constant char *
skipcond(p)410 skipcond(p)
411 register constant char *p;
412 {
413 register int iflevel;
414
415 /*
416 * We came in here after processing a ? or :,
417 * so we start nested one level deep.
418 */
419 iflevel = 1;
420
421 for (;;) switch (*++p)
422 {
423 case '?':
424 /*
425 * Start of a nested IF.
426 */
427 iflevel++;
428 break;
429 case ':':
430 /*
431 * Else.
432 * If this matches the IF we came in here with,
433 * then we're done.
434 */
435 if (iflevel == 1)
436 return (p);
437 break;
438 case '.':
439 /*
440 * Endif.
441 * If this matches the IF we came in here with,
442 * then we're done.
443 */
444 if (--iflevel == 0)
445 return (p);
446 break;
447 case '\\':
448 /*
449 * Backslash escapes the next character.
450 */
451 ++p;
452 break;
453 case '\0':
454 /*
455 * Whoops. Hit end of string.
456 * This is a malformed conditional, but just treat it
457 * as if all active conditionals ends here.
458 */
459 return (p-1);
460 }
461 /*NOTREACHED*/
462 }
463
464 /*
465 * Decode a char that represents a position on the screen.
466 */
467 static constant char *
wherechar(p,wp)468 wherechar(p, wp)
469 char constant *p;
470 int *wp;
471 {
472 switch (*p)
473 {
474 case 'b': case 'd': case 'l': case 'p': case 'P':
475 switch (*++p)
476 {
477 case 't': *wp = TOP; break;
478 case 'm': *wp = MIDDLE; break;
479 case 'b': *wp = BOTTOM; break;
480 case 'B': *wp = BOTTOM_PLUS_ONE; break;
481 case 'j': *wp = adjsline(jump_sline); break;
482 default: *wp = TOP; p--; break;
483 }
484 }
485 return (p);
486 }
487
488 /*
489 * Construct a message based on a prototype string.
490 */
491 public char *
pr_expand(proto,maxwidth)492 pr_expand(proto, maxwidth)
493 constant char *proto;
494 int maxwidth;
495 {
496 register constant char *p;
497 register int c;
498 int where;
499
500 mp = message;
501
502 if (*proto == '\0')
503 return ("");
504
505 for (p = proto; *p != '\0'; p++)
506 {
507 switch (*p)
508 {
509 default: /* Just put the character in the message */
510 ap_char(*p);
511 break;
512 case '\\': /* Backslash escapes the next character */
513 p++;
514 ap_char(*p);
515 break;
516 case '?': /* Conditional (IF) */
517 if ((c = *++p) == '\0')
518 --p;
519 else
520 {
521 where = 0;
522 p = wherechar(p, &where);
523 if (!cond(c, where))
524 p = skipcond(p);
525 }
526 break;
527 case ':': /* ELSE */
528 p = skipcond(p);
529 break;
530 case '.': /* ENDIF */
531 break;
532 case '%': /* Percent escape */
533 if ((c = *++p) == '\0')
534 --p;
535 else
536 {
537 where = 0;
538 p = wherechar(p, &where);
539 protochar(c, where,
540 #if EDITOR
541 (proto == editproto));
542 #else
543 0);
544 #endif
545
546 }
547 break;
548 }
549 }
550
551 if (mp == message)
552 return ("");
553 if (maxwidth > 0 && mp >= message + maxwidth)
554 {
555 /*
556 * Message is too long.
557 * Return just the final portion of it.
558 */
559 return (mp - maxwidth);
560 }
561 return (message);
562 }
563
564 /*
565 * Return a message suitable for printing by the "=" command.
566 */
567 public char *
eq_message()568 eq_message()
569 {
570 return (pr_expand(eqproto, 0));
571 }
572
573 /*
574 * Return a prompt.
575 * This depends on the prompt type (SHORT, MEDIUM, LONG), etc.
576 * If we can't come up with an appropriate prompt, return NULL
577 * and the caller will prompt with a colon.
578 */
579 public char *
pr_string()580 pr_string()
581 {
582 char *prompt;
583 int type;
584
585 type = (!less_is_more) ? pr_type : pr_type ? 0 : 1;
586 prompt = pr_expand((ch_getflags() & CH_HELPFILE) ?
587 hproto : prproto[type],
588 sc_width-so_s_width-so_e_width-2);
589 new_file = 0;
590 return (prompt);
591 }
592
593 /*
594 * Return a message suitable for printing while waiting in the F command.
595 */
596 public char *
wait_message()597 wait_message()
598 {
599 return (pr_expand(wproto, sc_width-so_s_width-so_e_width-2));
600 }
601