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