1 /*
2 * Copyright (C) 1984-2023 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 int header_lines;
33 extern IFILE curr_ifile;
34 #if EDITOR
35 extern char *editor;
36 extern char *editproto;
37 #endif
38
39 /*
40 * Prototypes for the three flavors of prompts.
41 * These strings are expanded by pr_expand().
42 */
43 static constant char s_proto[] =
44 "?n?f%f .?m(%T %i of %m) ..?e(END) ?x- Next\\: %x..%t";
45 static constant char m_proto[] =
46 "?n?f%f .?m(%T %i of %m) ..?e(END) ?x- Next\\: %x.:?pB%pB\\%:byte %bB?s/%s...%t";
47 static constant char M_proto[] =
48 "?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";
49 static constant char e_proto[] =
50 "?f%f .?m(%T %i of %m) .?ltlines %lt-%lb?L/%L. .byte %bB?s/%s. ?e(END) :?pB%pB\\%..%t";
51 static constant char h_proto[] =
52 "HELP -- ?eEND -- Press g to see it again:Press RETURN for more., or q when done";
53 static constant char w_proto[] =
54 "Waiting for data";
55 static constant char more_proto[] =
56 "--More--(?eEND ?x- Next\\: %x.:?pB%pB\\%:byte %bB?s/%s...%t)";
57
58 public char *prproto[3];
59 public char constant *eqproto = e_proto;
60 public char constant *hproto = h_proto;
61 public char constant *wproto = w_proto;
62
63 static char message[PROMPT_SIZE];
64 static char *mp;
65
66 /*
67 * Initialize the prompt prototype strings.
68 */
init_prompt(void)69 public void init_prompt(void)
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 */
ap_str(char * s)82 static void ap_str(char *s)
83 {
84 int len;
85
86 len = (int) strlen(s);
87 if (mp + len >= message + PROMPT_SIZE)
88 len = (int) (message + PROMPT_SIZE - mp - 1);
89 strncpy(mp, s, len);
90 mp += len;
91 *mp = '\0';
92 }
93
94 /*
95 * Append a character to the end of the message.
96 */
ap_char(char c)97 static void ap_char(char c)
98 {
99 char buf[2];
100
101 buf[0] = c;
102 buf[1] = '\0';
103 ap_str(buf);
104 }
105
106 /*
107 * Append a POSITION (as a decimal integer) to the end of the message.
108 */
ap_pos(POSITION pos)109 static void ap_pos(POSITION pos)
110 {
111 char buf[INT_STRLEN_BOUND(pos) + 2];
112
113 postoa(pos, buf, 10);
114 ap_str(buf);
115 }
116
117 /*
118 * Append a line number to the end of the message.
119 */
ap_linenum(LINENUM linenum)120 static void ap_linenum(LINENUM linenum)
121 {
122 char buf[INT_STRLEN_BOUND(linenum) + 2];
123
124 linenumtoa(linenum, buf, 10);
125 ap_str(buf);
126 }
127
128 /*
129 * Append an integer to the end of the message.
130 */
ap_int(int num)131 static void ap_int(int num)
132 {
133 char buf[INT_STRLEN_BOUND(num) + 2];
134
135 inttoa(num, buf, 10);
136 ap_str(buf);
137 }
138
139 /*
140 * Append a question mark to the end of the message.
141 */
ap_quest(void)142 static void ap_quest(void)
143 {
144 ap_str("?");
145 }
146
147 /*
148 * Return the "current" byte offset in the file.
149 */
curr_byte(int where)150 static POSITION curr_byte(int where)
151 {
152 POSITION pos;
153
154 pos = position(where);
155 while (pos == NULL_POSITION && where >= 0 && where < sc_height-1)
156 pos = position(++where);
157 if (pos == NULL_POSITION)
158 pos = ch_length();
159 return (pos);
160 }
161
162 /*
163 * Return the value of a prototype conditional.
164 * A prototype string may include conditionals which consist of a
165 * question mark followed by a single letter.
166 * Here we decode that letter and return the appropriate boolean value.
167 */
cond(char c,int where)168 static int cond(char c, int where)
169 {
170 POSITION len;
171
172 switch (c)
173 {
174 case 'a': /* Anything in the message yet? */
175 return (mp > message);
176 case 'b': /* Current byte offset known? */
177 return (curr_byte(where) != NULL_POSITION);
178 case 'c':
179 return (hshift != 0);
180 case 'e': /* At end of file? */
181 return (eof_displayed());
182 case 'f': /* Filename known? */
183 case 'g':
184 return (strcmp(get_filename(curr_ifile), "-") != 0);
185 case 'l': /* Line number known? */
186 case 'd': /* Same as l */
187 if (!linenums)
188 return 0;
189 return (currline(where) != 0);
190 case 'L': /* Final line number known? */
191 case 'D': /* Final page number known? */
192 return (linenums && ch_length() != NULL_POSITION);
193 case 'm': /* More than one file? */
194 #if TAGS
195 return (ntags() ? (ntags() > 1) : (nifile() > 1));
196 #else
197 return (nifile() > 1);
198 #endif
199 case 'n': /* First prompt in a new file? */
200 #if TAGS
201 return (ntags() ? 1 : new_file);
202 #else
203 return (new_file);
204 #endif
205 case 'p': /* Percent into file (bytes) known? */
206 return (curr_byte(where) != NULL_POSITION &&
207 ch_length() > 0);
208 case 'P': /* Percent into file (lines) known? */
209 return (currline(where) != 0 &&
210 (len = ch_length()) > 0 &&
211 find_linenum(len) != 0);
212 case 's': /* Size of file known? */
213 case 'B':
214 return (ch_length() != NULL_POSITION);
215 case 'x': /* Is there a "next" file? */
216 #if TAGS
217 if (ntags())
218 return (0);
219 #endif
220 return (next_ifile(curr_ifile) != NULL_IFILE);
221 }
222 return (0);
223 }
224
225 /*
226 * Decode a "percent" prototype character.
227 * A prototype string may include various "percent" escapes;
228 * that is, a percent sign followed by a single letter.
229 * Here we decode that letter and take the appropriate action,
230 * usually by appending something to the message being built.
231 */
protochar(int c,int where,int iseditproto)232 static void protochar(int c, int where, int iseditproto)
233 {
234 POSITION pos;
235 POSITION len;
236 int n;
237 LINENUM linenum;
238 LINENUM last_linenum;
239 IFILE h;
240 char *s;
241
242 #undef PAGE_NUM
243 #define PAGE_NUM(linenum) ((((linenum) - 1) / (sc_height - header_lines - 1)) + 1)
244
245 switch (c)
246 {
247 case 'b': /* Current byte offset */
248 pos = curr_byte(where);
249 if (pos != NULL_POSITION)
250 ap_pos(pos);
251 else
252 ap_quest();
253 break;
254 case 'c':
255 ap_int(hshift);
256 break;
257 case 'd': /* Current page number */
258 linenum = currline(where);
259 if (linenum > 0 && sc_height > header_lines + 1)
260 ap_linenum(PAGE_NUM(linenum));
261 else
262 ap_quest();
263 break;
264 case 'D': /* Final page number */
265 /* Find the page number of the last byte in the file (len-1). */
266 len = ch_length();
267 if (len == NULL_POSITION)
268 ap_quest();
269 else if (len == 0)
270 /* An empty file has no pages. */
271 ap_linenum(0);
272 else
273 {
274 linenum = find_linenum(len - 1);
275 if (linenum <= 0)
276 ap_quest();
277 else
278 ap_linenum(PAGE_NUM(linenum));
279 }
280 break;
281 #if EDITOR
282 case 'E': /* Editor name */
283 ap_str(editor);
284 break;
285 #endif
286 case 'f': /* File name */
287 ap_str(get_filename(curr_ifile));
288 break;
289 case 'F': /* Last component of file name */
290 ap_str(last_component(get_filename(curr_ifile)));
291 break;
292 case 'g': /* Shell-escaped file name */
293 s = shell_quote(get_filename(curr_ifile));
294 ap_str(s);
295 free(s);
296 break;
297 case 'i': /* Index into list of files */
298 #if TAGS
299 if (ntags())
300 ap_int(curr_tag());
301 else
302 #endif
303 ap_int(get_index(curr_ifile));
304 break;
305 case 'l': /* Current line number */
306 linenum = currline(where);
307 if (linenum != 0)
308 ap_linenum(vlinenum(linenum));
309 else
310 ap_quest();
311 break;
312 case 'L': /* Final line number */
313 len = ch_length();
314 if (len == NULL_POSITION || len == ch_zero() ||
315 (linenum = find_linenum(len)) <= 0)
316 ap_quest();
317 else
318 ap_linenum(vlinenum(linenum-1));
319 break;
320 case 'm': /* Number of files */
321 #if TAGS
322 n = ntags();
323 if (n)
324 ap_int(n);
325 else
326 #endif
327 ap_int(nifile());
328 break;
329 case 'p': /* Percent into file (bytes) */
330 pos = curr_byte(where);
331 len = ch_length();
332 if (pos != NULL_POSITION && len > 0)
333 ap_int(percentage(pos,len));
334 else
335 ap_quest();
336 break;
337 case 'P': /* Percent into file (lines) */
338 linenum = currline(where);
339 if (linenum == 0 ||
340 (len = ch_length()) == NULL_POSITION || len == ch_zero() ||
341 (last_linenum = find_linenum(len)) <= 0)
342 ap_quest();
343 else
344 ap_int(percentage(linenum, last_linenum));
345 break;
346 case 's': /* Size of file */
347 case 'B':
348 len = ch_length();
349 if (len != NULL_POSITION)
350 ap_pos(len);
351 else
352 ap_quest();
353 break;
354 case 't': /* Truncate trailing spaces in the message */
355 while (mp > message && mp[-1] == ' ')
356 mp--;
357 *mp = '\0';
358 break;
359 case 'T': /* Type of list */
360 #if TAGS
361 if (ntags())
362 ap_str("tag");
363 else
364 #endif
365 ap_str("file");
366 break;
367 case 'x': /* Name of next file */
368 h = next_ifile(curr_ifile);
369 if (h != NULL_IFILE)
370 ap_str(get_filename(h));
371 else
372 ap_quest();
373 break;
374 }
375 }
376
377 /*
378 * Skip a false conditional.
379 * When a false condition is found (either a false IF or the ELSE part
380 * of a true IF), this routine scans the prototype string to decide
381 * where to resume parsing the string.
382 * We must keep track of nested IFs and skip them properly.
383 */
skipcond(constant char * p)384 static constant char * skipcond(constant char *p)
385 {
386 int iflevel;
387
388 /*
389 * We came in here after processing a ? or :,
390 * so we start nested one level deep.
391 */
392 iflevel = 1;
393
394 for (;;) switch (*++p)
395 {
396 case '?':
397 /*
398 * Start of a nested IF.
399 */
400 iflevel++;
401 break;
402 case ':':
403 /*
404 * Else.
405 * If this matches the IF we came in here with,
406 * then we're done.
407 */
408 if (iflevel == 1)
409 return (p);
410 break;
411 case '.':
412 /*
413 * Endif.
414 * If this matches the IF we came in here with,
415 * then we're done.
416 */
417 if (--iflevel == 0)
418 return (p);
419 break;
420 case '\\':
421 /*
422 * Backslash escapes the next character.
423 */
424 if (p[1] != '\0')
425 ++p;
426 break;
427 case '\0':
428 /*
429 * Whoops. Hit end of string.
430 * This is a malformed conditional, but just treat it
431 * as if all active conditionals ends here.
432 */
433 return (p-1);
434 }
435 /*NOTREACHED*/
436 }
437
438 /*
439 * Decode a char that represents a position on the screen.
440 */
wherechar(char constant * p,int * wp)441 static constant char * wherechar(char constant *p, int *wp)
442 {
443 switch (*p)
444 {
445 case 'b': case 'd': case 'l': case 'p': case 'P':
446 switch (*++p)
447 {
448 case 't': *wp = TOP; break;
449 case 'm': *wp = MIDDLE; break;
450 case 'b': *wp = BOTTOM; break;
451 case 'B': *wp = BOTTOM_PLUS_ONE; break;
452 case 'j': *wp = sindex_from_sline(jump_sline); break;
453 default: *wp = TOP; p--; break;
454 }
455 }
456 return (p);
457 }
458
459 /*
460 * Construct a message based on a prototype string.
461 */
pr_expand(constant char * proto)462 public char * pr_expand(constant char *proto)
463 {
464 constant char *p;
465 int c;
466 int where;
467
468 mp = message;
469
470 if (*proto == '\0')
471 return ("");
472
473 for (p = proto; *p != '\0'; p++)
474 {
475 switch (*p)
476 {
477 default: /* Just put the character in the message */
478 ap_char(*p);
479 break;
480 case '\\': /* Backslash escapes the next character */
481 if (p[1] != '\0')
482 ap_char(*++p);
483 break;
484 case '?': /* Conditional (IF) */
485 if ((c = *++p) == '\0')
486 --p;
487 else
488 {
489 where = 0;
490 p = wherechar(p, &where);
491 if (!cond(c, where))
492 p = skipcond(p);
493 }
494 break;
495 case ':': /* ELSE */
496 p = skipcond(p);
497 break;
498 case '.': /* ENDIF */
499 break;
500 case '%': /* Percent escape */
501 if ((c = *++p) == '\0')
502 --p;
503 else
504 {
505 where = 0;
506 p = wherechar(p, &where);
507 protochar(c, where,
508 #if EDITOR
509 (proto == editproto));
510 #else
511 0);
512 #endif
513
514 }
515 break;
516 }
517 }
518
519 if (mp == message)
520 return ("");
521 return (message);
522 }
523
524 /*
525 * Return a message suitable for printing by the "=" command.
526 */
eq_message(void)527 public char * eq_message(void)
528 {
529 return (pr_expand(eqproto));
530 }
531
532 /*
533 * Return a prompt.
534 * This depends on the prompt type (SHORT, MEDIUM, LONG), etc.
535 * If we can't come up with an appropriate prompt, return NULL
536 * and the caller will prompt with a colon.
537 */
pr_string(void)538 public char * pr_string(void)
539 {
540 char *prompt;
541 int type;
542
543 type = (!less_is_more) ? pr_type : pr_type ? 0 : 1;
544 prompt = pr_expand((ch_getflags() & CH_HELPFILE) ?
545 hproto : prproto[type]);
546 new_file = 0;
547 return (prompt);
548 }
549
550 /*
551 * Return a message suitable for printing while waiting in the F command.
552 */
wait_message(void)553 public char * wait_message(void)
554 {
555 return (pr_expand(wproto));
556 }
557