1 /*
2 * Copyright (C) 1984-2024 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 * Prompting and other messages.
13 * There are three flavors of prompts, SHORT, MEDIUM and LONG,
14 * selected by the -m/-M options.
15 * There is also the "equals message", printed by the = command.
16 * A prompt is a message composed of various pieces, such as the
17 * name of the file being viewed, the percentage into the file, etc.
18 */
19
20 #include "less.h"
21 #include "position.h"
22
23 extern int pr_type;
24 extern lbool new_file;
25 extern int linenums;
26 extern int hshift;
27 extern int sc_height;
28 extern int jump_sline;
29 extern int less_is_more;
30 extern int header_lines;
31 extern int utf_mode;
32 extern IFILE curr_ifile;
33 #if OSC8_LINK
34 extern char *osc8_path;
35 #endif
36 #if EDITOR
37 extern constant char *editor;
38 extern constant char *editproto;
39 #endif
40
41 /*
42 * Prototypes for the three flavors of prompts.
43 * These strings are expanded by pr_expand().
44 */
45 static constant char s_proto[] =
46 "?n?f%f .?m(%T %i of %m) ..?e(END) ?x- Next\\: %x..%t";
47 static constant char m_proto[] =
48 "?n?f%f .?m(%T %i of %m) ..?e(END) ?x- Next\\: %x.:?pB%pB\\%:byte %bB?s/%s...%t";
49 static constant char M_proto[] =
50 "?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";
51 static constant char e_proto[] =
52 "?f%f .?m(%T %i of %m) .?ltlines %lt-%lb?L/%L. .byte %bB?s/%s. ?e(END) :?pB%pB\\%..%t";
53 static constant char h_proto[] =
54 "HELP -- ?eEND -- Press g to see it again:Press RETURN for more., or q when done";
55 static constant char w_proto[] =
56 "Waiting for data";
57 static constant char more_proto[] =
58 "--More--(?eEND ?x- Next\\: %x.:?pB%pB\\%:byte %bB?s/%s...%t)";
59
60 public char *prproto[3];
61 public char constant *eqproto = e_proto;
62 public char constant *hproto = h_proto;
63 public char constant *wproto = w_proto;
64
65 static char message[PROMPT_SIZE];
66 static char *mp;
67
68 /*
69 * Initialize the prompt prototype strings.
70 */
init_prompt(void)71 public void init_prompt(void)
72 {
73 prproto[0] = save(s_proto);
74 prproto[1] = save(less_is_more ? more_proto : m_proto);
75 prproto[2] = save(M_proto);
76 eqproto = save(e_proto);
77 hproto = save(h_proto);
78 wproto = save(w_proto);
79 }
80
81 /*
82 * Append a string to the end of the message.
83 * nprt means the character *may* be nonprintable
84 * and should be converted to printable form.
85 */
ap_estr(constant char * s,lbool nprt)86 static void ap_estr(constant char *s, lbool nprt)
87 {
88 constant char *es = s + strlen(s);
89 while (*s != '\0')
90 {
91 LWCHAR ch = step_charc(&s, +1, es);
92 constant char *ps;
93 char ubuf[MAX_UTF_CHAR_LEN+1];
94 size_t plen;
95
96 if (nprt)
97 {
98 ps = utf_mode ? prutfchar(ch) : prchar(ch);
99 } else
100 {
101 char *up = ubuf;
102 put_wchar(&up, ch);
103 *up = '\0';
104 ps = ubuf;
105 }
106 plen = strlen(ps);
107 if (mp + plen >= message + PROMPT_SIZE)
108 break;
109 strcpy(mp, ps);
110 mp += plen;
111 }
112 *mp = '\0';
113 }
114
ap_str(constant char * s)115 static void ap_str(constant char *s)
116 {
117 ap_estr(s, FALSE);
118 }
119
120
121 /*
122 * Append a character to the end of the message.
123 */
ap_char(char c)124 static void ap_char(char c)
125 {
126 char buf[2];
127
128 buf[0] = c;
129 buf[1] = '\0';
130 ap_str(buf);
131 }
132
133 /*
134 * Append a POSITION (as a decimal integer) to the end of the message.
135 */
ap_pos(POSITION pos)136 static void ap_pos(POSITION pos)
137 {
138 char buf[INT_STRLEN_BOUND(pos) + 2];
139
140 postoa(pos, buf, 10);
141 ap_str(buf);
142 }
143
144 /*
145 * Append a line number to the end of the message.
146 */
ap_linenum(LINENUM linenum)147 static void ap_linenum(LINENUM linenum)
148 {
149 char buf[INT_STRLEN_BOUND(linenum) + 2];
150
151 linenumtoa(linenum, buf, 10);
152 ap_str(buf);
153 }
154
155 /*
156 * Append an integer to the end of the message.
157 */
ap_int(int num)158 static void ap_int(int num)
159 {
160 char buf[INT_STRLEN_BOUND(num) + 2];
161
162 inttoa(num, buf, 10);
163 ap_str(buf);
164 }
165
166 /*
167 * Append a question mark to the end of the message.
168 */
ap_quest(void)169 static void ap_quest(void)
170 {
171 ap_str("?");
172 }
173
174 /*
175 * Return the "current" byte offset in the file.
176 */
curr_byte(int where)177 static POSITION curr_byte(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 */
cond(char c,int where)195 static lbool cond(char c, int where)
196 {
197 POSITION len;
198
199 switch (c)
200 {
201 case 'a': /* Anything in the message yet? */
202 return (mp > message);
203 case 'b': /* Current byte offset known? */
204 return (curr_byte(where) != NULL_POSITION);
205 case 'c':
206 return (hshift != 0);
207 case 'e': /* At end of file? */
208 return (eof_displayed());
209 case 'f': /* Filename known? */
210 case 'g':
211 return (strcmp(get_filename(curr_ifile), "-") != 0);
212 case 'l': /* Line number known? */
213 case 'd': /* Same as l */
214 if (!linenums)
215 return FALSE;
216 return (currline(where) != 0);
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() ? TRUE : new_file ? TRUE : FALSE);
229 #else
230 return (new_file ? TRUE : FALSE);
231 #endif
232 case 'p': /* Percent into file (bytes) known? */
233 return (curr_byte(where) != NULL_POSITION && ch_length() > 0);
234 case 'P': /* Percent into file (lines) known? */
235 return (currline(where) != 0 &&
236 (len = ch_length()) > 0 &&
237 find_linenum(len) != 0);
238 case 's': /* Size of file known? */
239 case 'B':
240 return (ch_length() != NULL_POSITION);
241 case 'x': /* Is there a "next" file? */
242 #if TAGS
243 if (ntags())
244 return (FALSE);
245 #endif
246 return (next_ifile(curr_ifile) != NULL_IFILE);
247 }
248 return (FALSE);
249 }
250
251 /*
252 * Decode a "percent" prototype character.
253 * A prototype string may include various "percent" escapes;
254 * that is, a percent sign followed by a single letter.
255 * Here we decode that letter and take the appropriate action,
256 * usually by appending something to the message being built.
257 */
protochar(char c,int where)258 static void protochar(char c, int where)
259 {
260 POSITION pos;
261 POSITION len;
262 int n;
263 LINENUM linenum;
264 LINENUM last_linenum;
265 IFILE h;
266 char *s;
267
268 #undef PAGE_NUM
269 #define PAGE_NUM(linenum) ((((linenum) - 1) / (sc_height - header_lines - 1)) + 1)
270
271 switch (c)
272 {
273 case 'b': /* Current byte offset */
274 pos = curr_byte(where);
275 if (pos != NULL_POSITION)
276 ap_pos(pos);
277 else
278 ap_quest();
279 break;
280 case 'c':
281 ap_int(hshift);
282 break;
283 case 'd': /* Current page number */
284 linenum = currline(where);
285 if (linenum > 0 && sc_height > header_lines + 1)
286 ap_linenum(PAGE_NUM(linenum));
287 else
288 ap_quest();
289 break;
290 case 'D': /* Final page number */
291 /* Find the page number of the last byte in the file (len-1). */
292 len = ch_length();
293 if (len == NULL_POSITION)
294 ap_quest();
295 else if (len == 0)
296 /* An empty file has no pages. */
297 ap_linenum(0);
298 else
299 {
300 linenum = find_linenum(len - 1);
301 if (linenum <= 0)
302 ap_quest();
303 else
304 ap_linenum(PAGE_NUM(linenum));
305 }
306 break;
307 #if EDITOR
308 case 'E': /* Editor name */
309 ap_str(editor);
310 break;
311 #endif
312 case 'f': /* File name */
313 ap_estr(get_filename(curr_ifile), TRUE);
314 break;
315 case 'F': /* Last component of file name */
316 ap_estr(last_component(get_filename(curr_ifile)), TRUE);
317 break;
318 case 'g': /* Shell-escaped file name */
319 s = shell_quote(get_filename(curr_ifile));
320 ap_str(s);
321 free(s);
322 break;
323 case 'i': /* Index into list of files */
324 #if TAGS
325 if (ntags())
326 ap_int(curr_tag());
327 else
328 #endif
329 ap_int(get_index(curr_ifile));
330 break;
331 case 'l': /* Current line number */
332 linenum = currline(where);
333 if (linenum != 0)
334 ap_linenum(vlinenum(linenum));
335 else
336 ap_quest();
337 break;
338 case 'L': /* Final line number */
339 len = ch_length();
340 if (len == NULL_POSITION || len == ch_zero() ||
341 (linenum = find_linenum(len)) <= 0)
342 ap_quest();
343 else
344 ap_linenum(vlinenum(linenum-1));
345 break;
346 case 'm': /* Number of files */
347 #if TAGS
348 n = ntags();
349 if (n)
350 ap_int(n);
351 else
352 #endif
353 ap_int(nifile());
354 break;
355 case 'o': /* path (URI without protocol) of selected OSC8 link */
356 #if OSC8_LINK
357 if (osc8_path != NULL)
358 ap_str(osc8_path);
359 else
360 #endif
361 ap_quest();
362 break;
363 case 'p': /* Percent into file (bytes) */
364 pos = curr_byte(where);
365 len = ch_length();
366 if (pos != NULL_POSITION && len > 0)
367 ap_int(percentage(pos,len));
368 else
369 ap_quest();
370 break;
371 case 'P': /* Percent into file (lines) */
372 linenum = currline(where);
373 if (linenum == 0 ||
374 (len = ch_length()) == NULL_POSITION || len == ch_zero() ||
375 (last_linenum = find_linenum(len)) <= 0)
376 ap_quest();
377 else
378 ap_int(percentage(linenum, last_linenum));
379 break;
380 case 's': /* Size of file */
381 case 'B':
382 len = ch_length();
383 if (len != NULL_POSITION)
384 ap_pos(len);
385 else
386 ap_quest();
387 break;
388 case 't': /* Truncate trailing spaces in the message */
389 while (mp > message && mp[-1] == ' ')
390 mp--;
391 *mp = '\0';
392 break;
393 case 'T': /* Type of list */
394 #if TAGS
395 if (ntags())
396 ap_str("tag");
397 else
398 #endif
399 ap_str("file");
400 break;
401 case 'x': /* Name of next file */
402 h = next_ifile(curr_ifile);
403 if (h != NULL_IFILE)
404 ap_str(get_filename(h));
405 else
406 ap_quest();
407 break;
408 }
409 }
410
411 /*
412 * Skip a false conditional.
413 * When a false condition is found (either a false IF or the ELSE part
414 * of a true IF), this routine scans the prototype string to decide
415 * where to resume parsing the string.
416 * We must keep track of nested IFs and skip them properly.
417 */
skipcond(constant char * p)418 static constant char * skipcond(constant char *p)
419 {
420 int iflevel;
421
422 /*
423 * We came in here after processing a ? or :,
424 * so we start nested one level deep.
425 */
426 iflevel = 1;
427
428 for (;;) switch (*++p)
429 {
430 case '?':
431 /*
432 * Start of a nested IF.
433 */
434 iflevel++;
435 break;
436 case ':':
437 /*
438 * Else.
439 * If this matches the IF we came in here with,
440 * then we're done.
441 */
442 if (iflevel == 1)
443 return (p);
444 break;
445 case '.':
446 /*
447 * Endif.
448 * If this matches the IF we came in here with,
449 * then we're done.
450 */
451 if (--iflevel == 0)
452 return (p);
453 break;
454 case '\\':
455 /*
456 * Backslash escapes the next character.
457 */
458 if (p[1] != '\0')
459 ++p;
460 break;
461 case '\0':
462 /*
463 * Whoops. Hit end of string.
464 * This is a malformed conditional, but just treat it
465 * as if all active conditionals ends here.
466 */
467 return (p-1);
468 }
469 /*NOTREACHED*/
470 }
471
472 /*
473 * Decode a char that represents a position on the screen.
474 */
wherechar(char constant * p,int * wp)475 static constant char * wherechar(char constant *p, int *wp)
476 {
477 switch (*p)
478 {
479 case 'b': case 'd': case 'l': case 'p': case 'P':
480 switch (*++p)
481 {
482 case 't': *wp = TOP; break;
483 case 'm': *wp = MIDDLE; break;
484 case 'b': *wp = BOTTOM; break;
485 case 'B': *wp = BOTTOM_PLUS_ONE; break;
486 case 'j': *wp = sindex_from_sline(jump_sline); break;
487 default: *wp = TOP; p--; break;
488 }
489 }
490 return (p);
491 }
492
493 /*
494 * Construct a message based on a prototype string.
495 */
pr_expand(constant char * proto)496 public constant char * pr_expand(constant char *proto)
497 {
498 constant char *p;
499 char c;
500 int where;
501
502 mp = message;
503
504 if (*proto == '\0')
505 return ("");
506
507 for (p = proto; *p != '\0'; p++)
508 {
509 switch (*p)
510 {
511 default: /* Just put the character in the message */
512 ap_char(*p);
513 break;
514 case '\\': /* Backslash escapes the next character */
515 if (p[1] != '\0')
516 ap_char(*++p);
517 break;
518 case '?': /* Conditional (IF) */
519 if ((c = *++p) == '\0')
520 --p;
521 else
522 {
523 where = 0;
524 p = wherechar(p, &where);
525 if (!cond(c, where))
526 p = skipcond(p);
527 }
528 break;
529 case ':': /* ELSE */
530 p = skipcond(p);
531 break;
532 case '.': /* ENDIF */
533 break;
534 case '%': /* Percent escape */
535 if ((c = *++p) == '\0')
536 --p;
537 else
538 {
539 where = 0;
540 p = wherechar(p, &where);
541 protochar(c, where);
542 }
543 break;
544 }
545 }
546
547 if (mp == message)
548 return ("");
549 return (message);
550 }
551
552 /*
553 * Return a message suitable for printing by the "=" command.
554 */
eq_message(void)555 public constant char * eq_message(void)
556 {
557 return (pr_expand(eqproto));
558 }
559
560 /*
561 * Return a prompt.
562 * This depends on the prompt type (SHORT, MEDIUM, LONG), etc.
563 * If we can't come up with an appropriate prompt, return NULL
564 * and the caller will prompt with a colon.
565 */
pr_string(void)566 public constant char * pr_string(void)
567 {
568 constant char *prompt;
569 int type;
570
571 type = (!less_is_more) ? pr_type : pr_type ? 0 : 1;
572 prompt = pr_expand((ch_getflags() & CH_HELPFILE) ?
573 hproto : prproto[type]);
574 new_file = FALSE;
575 return (prompt);
576 }
577
578 /*
579 * Return a message suitable for printing while waiting in the F command.
580 */
wait_message(void)581 public constant char * wait_message(void)
582 {
583 return (pr_expand(wproto));
584 }
585