1 /*
2 * Copyright (C) 1984-2002 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 * Prompting and other messages.
14 * There are three flavors of prompts, SHORT, MEDIUM and LONG,
15 * selected by the -m/-M options.
16 * There is also the "equals message", printed by the = command.
17 * A prompt is a message composed of various pieces, such as the
18 * name of the file being viewed, the percentage into the file, etc.
19 */
20
21 #include "less.h"
22 #include "position.h"
23
24 extern int pr_type;
25 extern int hit_eof;
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 ismore;
32 extern int sc_height;
33 extern int jump_sline;
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 "?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 more_proto[] =
51 "--More--.?e(END) ?x- Next\\: %x.:(?pB%pB\\%:byte %bB?s/%s..).%t";
52 static constant char e_proto[] =
53 "?f%f .?m(%T %i of %m) .?ltlines %lt-%lb?L/%L. .byte %bB?s/%s. ?e(END) :?pB%pB\\%..%t";
54 static constant char h_proto[] =
55 "HELP -- ?eEND -- Press g to see it again:Press RETURN for more., or q when done";
56 static constant char w_proto[] =
57 "Waiting for data";
58
59 public char *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 /*
68 * Initialize the prompt prototype strings.
69 */
70 public void
init_prompt()71 init_prompt()
72 {
73 prproto[0] = save(ismore ? more_proto : s_proto);
74 prproto[1] = save(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 */
84 static void
ap_str(s)85 ap_str(s)
86 char *s;
87 {
88 int len;
89
90 len = strlen(s);
91 if (mp + len >= message + PROMPT_SIZE)
92 len = message + PROMPT_SIZE - mp - 1;
93 strncpy(mp, s, len);
94 mp += len;
95 *mp = '\0';
96 }
97
98 /*
99 * Append a character to the end of the message.
100 */
101 static void
ap_char(c)102 ap_char(c)
103 char c;
104 {
105 char buf[2];
106
107 buf[0] = c;
108 buf[1] = '\0';
109 ap_str(buf);
110 }
111
112 /*
113 * Append a POSITION (as a decimal integer) to the end of the message.
114 */
115 static void
ap_pos(pos)116 ap_pos(pos)
117 POSITION pos;
118 {
119 char buf[INT_STRLEN_BOUND(pos) + 2];
120
121 postoa(pos, buf, sizeof(buf));
122 ap_str(buf);
123 }
124
125 /*
126 * Append a line number to the end of the message.
127 */
128 static void
ap_linenum(linenum)129 ap_linenum(linenum)
130 LINENUM linenum;
131 {
132 char buf[INT_STRLEN_BOUND(linenum) + 2];
133
134 linenumtoa(linenum, buf, sizeof(buf));
135 ap_str(buf);
136 }
137
138 /*
139 * Append an integer to the end of the message.
140 */
141 static void
ap_int(num)142 ap_int(num)
143 int num;
144 {
145 char buf[INT_STRLEN_BOUND(num) + 2];
146
147 inttoa(num, buf, sizeof(buf));
148 ap_str(buf);
149 }
150
151 /*
152 * Append a question mark to the end of the message.
153 */
154 static void
ap_quest()155 ap_quest()
156 {
157 ap_str("?");
158 }
159
160 /*
161 * Return the "current" byte offset in the file.
162 */
163 static POSITION
curr_byte(where)164 curr_byte(where)
165 int where;
166 {
167 POSITION pos;
168
169 pos = position(where);
170 while (pos == NULL_POSITION && where >= 0 && where < sc_height)
171 pos = position(++where);
172 if (pos == NULL_POSITION)
173 pos = ch_length();
174 return (pos);
175 }
176
177 /*
178 * Return the value of a prototype conditional.
179 * A prototype string may include conditionals which consist of a
180 * question mark followed by a single letter.
181 * Here we decode that letter and return the appropriate boolean value.
182 */
183 static int
cond(c,where)184 cond(c, where)
185 char c;
186 int where;
187 {
188 POSITION len;
189
190 switch (c)
191 {
192 case 'a': /* Anything in the message yet? */
193 return (mp > message);
194 case 'b': /* Current byte offset known? */
195 return (curr_byte(where) != NULL_POSITION);
196 case 'c':
197 return (hshift != 0);
198 case 'e': /* At end of file? */
199 return (hit_eof);
200 case 'f': /* Filename known? */
201 return (strcmp(get_filename(curr_ifile), "-") != 0);
202 case 'l': /* Line number known? */
203 case 'd': /* Same as l */
204 return (linenums);
205 case 'L': /* Final line number known? */
206 case 'D': /* Same as L */
207 return (linenums && ch_length() != NULL_POSITION);
208 case 'm': /* More than one file? */
209 #if TAGS
210 return (ntags() ? (ntags() > 1) : (nifile() > 1));
211 #else
212 return (nifile() > 1);
213 #endif
214 case 'n': /* First prompt in a new file? */
215 #if TAGS
216 return (ntags() ? 1 : new_file);
217 #else
218 return (new_file);
219 #endif
220 case 'p': /* Percent into file (bytes) known? */
221 return (curr_byte(where) != NULL_POSITION &&
222 ch_length() > 0);
223 case 'P': /* Percent into file (lines) known? */
224 return (currline(where) != 0 &&
225 (len = ch_length()) > 0 &&
226 find_linenum(len) != 0);
227 case 's': /* Size of file known? */
228 case 'B':
229 return (ch_length() != NULL_POSITION);
230 case 'x': /* Is there a "next" file? */
231 #if TAGS
232 if (ntags())
233 return (0);
234 #endif
235 return (next_ifile(curr_ifile) != NULL_IFILE);
236 }
237 return (0);
238 }
239
240 /*
241 * Decode a "percent" prototype character.
242 * A prototype string may include various "percent" escapes;
243 * that is, a percent sign followed by a single letter.
244 * Here we decode that letter and take the appropriate action,
245 * usually by appending something to the message being built.
246 */
247 static void
protochar(c,where,iseditproto)248 protochar(c, where, iseditproto)
249 int c;
250 int where;
251 int iseditproto;
252 {
253 POSITION pos;
254 POSITION len;
255 int n;
256 LINENUM linenum;
257 LINENUM last_linenum;
258 IFILE h;
259
260 switch (c)
261 {
262 case 'b': /* Current byte offset */
263 pos = curr_byte(where);
264 if (pos != NULL_POSITION)
265 ap_pos(pos);
266 else
267 ap_quest();
268 break;
269 case 'c':
270 ap_int(hshift);
271 break;
272 case 'd': /* Current page number */
273 linenum = currline(where);
274 if (linenum > 0 && sc_height > 1)
275 ap_linenum(((linenum - 1) / (sc_height - 1)) + 1);
276 else
277 ap_quest();
278 break;
279 case 'D': /* Last page number */
280 len = ch_length();
281 if (len == NULL_POSITION || len == ch_zero() ||
282 (linenum = find_linenum(len)) <= 0)
283 ap_quest();
284 else
285 ap_linenum(((linenum - 1) / (sc_height - 1)) + 1);
286 break;
287 #if EDITOR
288 case 'E': /* Editor name */
289 ap_str(editor);
290 break;
291 #endif
292 case 'f': /* File name */
293 ap_str(get_filename(curr_ifile));
294 break;
295 case 'i': /* Index into list of files */
296 #if TAGS
297 if (ntags())
298 ap_int(curr_tag());
299 else
300 #endif
301 ap_int(get_index(curr_ifile));
302 break;
303 case 'l': /* Current line number */
304 linenum = currline(where);
305 if (linenum != 0)
306 ap_linenum(linenum);
307 else
308 ap_quest();
309 break;
310 case 'L': /* Final line number */
311 len = ch_length();
312 if (len == NULL_POSITION || len == ch_zero() ||
313 (linenum = find_linenum(len)) <= 0)
314 ap_quest();
315 else
316 ap_linenum(linenum-1);
317 break;
318 case 'm': /* Number of files */
319 #if TAGS
320 n = ntags();
321 if (n)
322 ap_int(n);
323 else
324 #endif
325 ap_int(nifile());
326 break;
327 case 'p': /* Percent into file (bytes) */
328 pos = curr_byte(where);
329 len = ch_length();
330 if (pos != NULL_POSITION && len > 0)
331 ap_int(percentage(pos,len));
332 else
333 ap_quest();
334 break;
335 case 'P': /* Percent into file (lines) */
336 linenum = currline(where);
337 if (linenum == 0 ||
338 (len = ch_length()) == NULL_POSITION || len == ch_zero() ||
339 (last_linenum = find_linenum(len)) <= 0)
340 ap_quest();
341 else
342 ap_int(percentage(linenum, last_linenum));
343 break;
344 case 's': /* Size of file */
345 case 'B':
346 len = ch_length();
347 if (len != NULL_POSITION)
348 ap_pos(len);
349 else
350 ap_quest();
351 break;
352 case 't': /* Truncate trailing spaces in the message */
353 while (mp > message && mp[-1] == ' ')
354 mp--;
355 break;
356 case 'T': /* Type of list */
357 #if TAGS
358 if (ntags())
359 ap_str("tag");
360 else
361 #endif
362 ap_str("file");
363 break;
364 case 'x': /* Name of next file */
365 h = next_ifile(curr_ifile);
366 if (h != NULL_IFILE)
367 ap_str(get_filename(h));
368 else
369 ap_quest();
370 break;
371 }
372 }
373
374 /*
375 * Skip a false conditional.
376 * When a false condition is found (either a false IF or the ELSE part
377 * of a true IF), this routine scans the prototype string to decide
378 * where to resume parsing the string.
379 * We must keep track of nested IFs and skip them properly.
380 */
381 static char *
skipcond(p)382 skipcond(p)
383 register char *p;
384 {
385 register int iflevel;
386
387 /*
388 * We came in here after processing a ? or :,
389 * so we start nested one level deep.
390 */
391 iflevel = 1;
392
393 for (;;) switch (*++p)
394 {
395 case '?':
396 /*
397 * Start of a nested IF.
398 */
399 iflevel++;
400 break;
401 case ':':
402 /*
403 * Else.
404 * If this matches the IF we came in here with,
405 * then we're done.
406 */
407 if (iflevel == 1)
408 return (p);
409 break;
410 case '.':
411 /*
412 * Endif.
413 * If this matches the IF we came in here with,
414 * then we're done.
415 */
416 if (--iflevel == 0)
417 return (p);
418 break;
419 case '\\':
420 /*
421 * Backslash escapes the next character.
422 */
423 ++p;
424 break;
425 case '\0':
426 /*
427 * Whoops. Hit end of string.
428 * This is a malformed conditional, but just treat it
429 * as if all active conditionals ends here.
430 */
431 return (p-1);
432 }
433 /*NOTREACHED*/
434 }
435
436 /*
437 * Decode a char that represents a position on the screen.
438 */
439 static char *
wherechar(p,wp)440 wherechar(p, wp)
441 char *p;
442 int *wp;
443 {
444 switch (*p)
445 {
446 case 'b': case 'd': case 'l': case 'p': case 'P':
447 switch (*++p)
448 {
449 case 't': *wp = TOP; break;
450 case 'm': *wp = MIDDLE; break;
451 case 'b': *wp = BOTTOM; break;
452 case 'B': *wp = BOTTOM_PLUS_ONE; break;
453 case 'j': *wp = adjsline(jump_sline); break;
454 default: *wp = TOP; p--; break;
455 }
456 }
457 return (p);
458 }
459
460 /*
461 * Construct a message based on a prototype string.
462 */
463 public char *
pr_expand(proto,maxwidth)464 pr_expand(proto, maxwidth)
465 char *proto;
466 int maxwidth;
467 {
468 register char *p;
469 register int c;
470 int where;
471
472 mp = message;
473
474 if (*proto == '\0')
475 return ("");
476
477 for (p = proto; *p != '\0'; p++)
478 {
479 switch (*p)
480 {
481 default: /* Just put the character in the message */
482 ap_char(*p);
483 break;
484 case '\\': /* Backslash escapes the next character */
485 p++;
486 ap_char(*p);
487 break;
488 case '?': /* Conditional (IF) */
489 if ((c = *++p) == '\0')
490 --p;
491 else
492 {
493 where = 0;
494 p = wherechar(p, &where);
495 if (!cond(c, where))
496 p = skipcond(p);
497 }
498 break;
499 case ':': /* ELSE */
500 p = skipcond(p);
501 break;
502 case '.': /* ENDIF */
503 break;
504 case '%': /* Percent escape */
505 if ((c = *++p) == '\0')
506 --p;
507 else
508 {
509 where = 0;
510 p = wherechar(p, &where);
511 protochar(c, where,
512 #if EDITOR
513 (proto == editproto));
514 #else
515 0);
516 #endif
517
518 }
519 break;
520 }
521 }
522
523 if (mp == message)
524 return (NULL);
525 if (maxwidth > 0 && mp >= message + maxwidth)
526 {
527 /*
528 * Message is too long.
529 * Return just the final portion of it.
530 */
531 return (mp - maxwidth);
532 }
533 return (message);
534 }
535
536 /*
537 * Return a message suitable for printing by the "=" command.
538 */
539 public char *
eq_message()540 eq_message()
541 {
542 return (pr_expand(eqproto, 0));
543 }
544
545 /*
546 * Return a prompt.
547 * This depends on the prompt type (SHORT, MEDIUM, LONG), etc.
548 * If we can't come up with an appropriate prompt, return NULL
549 * and the caller will prompt with a colon.
550 */
551 public char *
pr_string()552 pr_string()
553 {
554 char *prompt;
555
556 prompt = pr_expand(prproto[pr_type], sc_width-so_s_width-so_e_width-2);
557 new_file = 0;
558 return (prompt);
559 }
560
561 /*
562 * Return a message suitable for printing while waiting in the F command.
563 */
564 public char *
wait_message()565 wait_message()
566 {
567 return (pr_expand(wproto, sc_width-so_s_width-so_e_width-2));
568 }
569