("" < 3.4) always evaluates to true, which unconditionally
[dragonfly.git] / contrib / less-381 / prompt.c
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1 /*
2 * Copyright (C) 1984-2002 Mark Nudelman
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.
7 * For more information about less, or for information on how to
8 * contact the author, see the README file.
9 */
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.
21 #include "less.h"
22 #include "position.h"
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 sc_height;
32 extern int jump_sline;
33 extern IFILE curr_ifile;
34 #if EDITOR
35 extern char *editor;
36 extern char *editproto;
37 #endif
40 * Prototypes for the three flavors of prompts.
41 * These strings are expanded by pr_expand().
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";
56 public char *prproto[3];
57 public char constant *eqproto = e_proto;
58 public char constant *hproto = h_proto;
59 public char constant *wproto = w_proto;
61 static char message[PROMPT_SIZE];
62 static char *mp;
65 * Initialize the prompt prototype strings.
67 public void
68 init_prompt()
70 prproto[0] = save(s_proto);
71 prproto[1] = save(m_proto);
72 prproto[2] = save(M_proto);
73 eqproto = save(e_proto);
74 hproto = save(h_proto);
75 wproto = save(w_proto);
79 * Append a string to the end of the message.
81 static void
82 ap_str(s)
83 char *s;
85 int len;
87 len = strlen(s);
88 if (mp + len >= message + PROMPT_SIZE)
89 len = message + PROMPT_SIZE - mp - 1;
90 strncpy(mp, s, len);
91 mp += len;
92 *mp = '\0';
96 * Append a character to the end of the message.
98 static void
99 ap_char(c)
100 char c;
102 char buf[2];
104 buf[0] = c;
105 buf[1] = '\0';
106 ap_str(buf);
110 * Append a POSITION (as a decimal integer) to the end of the message.
112 static void
113 ap_pos(pos)
114 POSITION pos;
116 char buf[INT_STRLEN_BOUND(pos) + 2];
118 postoa(pos, buf);
119 ap_str(buf);
123 * Append a line number to the end of the message.
125 static void
126 ap_linenum(linenum)
127 LINENUM linenum;
129 char buf[INT_STRLEN_BOUND(linenum) + 2];
131 linenumtoa(linenum, buf);
132 ap_str(buf);
136 * Append an integer to the end of the message.
138 static void
139 ap_int(num)
140 int num;
142 char buf[INT_STRLEN_BOUND(num) + 2];
144 inttoa(num, buf);
145 ap_str(buf);
149 * Append a question mark to the end of the message.
151 static void
152 ap_quest()
154 ap_str("?");
158 * Return the "current" byte offset in the file.
160 static POSITION
161 curr_byte(where)
162 int where;
164 POSITION pos;
166 pos = position(where);
167 while (pos == NULL_POSITION && where >= 0 && where < sc_height)
168 pos = position(++where);
169 if (pos == NULL_POSITION)
170 pos = ch_length();
171 return (pos);
175 * Return the value of a prototype conditional.
176 * A prototype string may include conditionals which consist of a
177 * question mark followed by a single letter.
178 * Here we decode that letter and return the appropriate boolean value.
180 static int
181 cond(c, where)
182 char c;
183 int where;
185 POSITION len;
187 switch (c)
189 case 'a': /* Anything in the message yet? */
190 return (mp > message);
191 case 'b': /* Current byte offset known? */
192 return (curr_byte(where) != NULL_POSITION);
193 case 'c':
194 return (hshift != 0);
195 case 'e': /* At end of file? */
196 return (hit_eof);
197 case 'f': /* Filename known? */
198 return (strcmp(get_filename(curr_ifile), "-") != 0);
199 case 'l': /* Line number known? */
200 case 'd': /* Same as l */
201 return (linenums);
202 case 'L': /* Final line number known? */
203 case 'D': /* Same as L */
204 return (linenums && ch_length() != NULL_POSITION);
205 case 'm': /* More than one file? */
206 #if TAGS
207 return (ntags() ? (ntags() > 1) : (nifile() > 1));
208 #else
209 return (nifile() > 1);
210 #endif
211 case 'n': /* First prompt in a new file? */
212 #if TAGS
213 return (ntags() ? 1 : new_file);
214 #else
215 return (new_file);
216 #endif
217 case 'p': /* Percent into file (bytes) known? */
218 return (curr_byte(where) != NULL_POSITION &&
219 ch_length() > 0);
220 case 'P': /* Percent into file (lines) known? */
221 return (currline(where) != 0 &&
222 (len = ch_length()) > 0 &&
223 find_linenum(len) != 0);
224 case 's': /* Size of file known? */
225 case 'B':
226 return (ch_length() != NULL_POSITION);
227 case 'x': /* Is there a "next" file? */
228 #if TAGS
229 if (ntags())
230 return (0);
231 #endif
232 return (next_ifile(curr_ifile) != NULL_IFILE);
234 return (0);
238 * Decode a "percent" prototype character.
239 * A prototype string may include various "percent" escapes;
240 * that is, a percent sign followed by a single letter.
241 * Here we decode that letter and take the appropriate action,
242 * usually by appending something to the message being built.
244 static void
245 protochar(c, where, iseditproto)
246 int c;
247 int where;
248 int iseditproto;
250 POSITION pos;
251 POSITION len;
252 int n;
253 LINENUM linenum;
254 LINENUM last_linenum;
255 IFILE h;
257 switch (c)
259 case 'b': /* Current byte offset */
260 pos = curr_byte(where);
261 if (pos != NULL_POSITION)
262 ap_pos(pos);
263 else
264 ap_quest();
265 break;
266 case 'c':
267 ap_int(hshift);
268 break;
269 case 'd': /* Current page number */
270 linenum = currline(where);
271 if (linenum > 0 && sc_height > 1)
272 ap_linenum(((linenum - 1) / (sc_height - 1)) + 1);
273 else
274 ap_quest();
275 break;
276 case 'D': /* Last page number */
277 len = ch_length();
278 if (len == NULL_POSITION || len == ch_zero() ||
279 (linenum = find_linenum(len)) <= 0)
280 ap_quest();
281 else
282 ap_linenum(((linenum - 1) / (sc_height - 1)) + 1);
283 break;
284 #if EDITOR
285 case 'E': /* Editor name */
286 ap_str(editor);
287 break;
288 #endif
289 case 'f': /* File name */
290 ap_str(get_filename(curr_ifile));
291 break;
292 case 'i': /* Index into list of files */
293 #if TAGS
294 if (ntags())
295 ap_int(curr_tag());
296 else
297 #endif
298 ap_int(get_index(curr_ifile));
299 break;
300 case 'l': /* Current line number */
301 linenum = currline(where);
302 if (linenum != 0)
303 ap_linenum(linenum);
304 else
305 ap_quest();
306 break;
307 case 'L': /* Final line number */
308 len = ch_length();
309 if (len == NULL_POSITION || len == ch_zero() ||
310 (linenum = find_linenum(len)) <= 0)
311 ap_quest();
312 else
313 ap_linenum(linenum-1);
314 break;
315 case 'm': /* Number of files */
316 #if TAGS
317 n = ntags();
318 if (n)
319 ap_int(n);
320 else
321 #endif
322 ap_int(nifile());
323 break;
324 case 'p': /* Percent into file (bytes) */
325 pos = curr_byte(where);
326 len = ch_length();
327 if (pos != NULL_POSITION && len > 0)
328 ap_int(percentage(pos,len));
329 else
330 ap_quest();
331 break;
332 case 'P': /* Percent into file (lines) */
333 linenum = currline(where);
334 if (linenum == 0 ||
335 (len = ch_length()) == NULL_POSITION || len == ch_zero() ||
336 (last_linenum = find_linenum(len)) <= 0)
337 ap_quest();
338 else
339 ap_int(percentage(linenum, last_linenum));
340 break;
341 case 's': /* Size of file */
342 case 'B':
343 len = ch_length();
344 if (len != NULL_POSITION)
345 ap_pos(len);
346 else
347 ap_quest();
348 break;
349 case 't': /* Truncate trailing spaces in the message */
350 while (mp > message && mp[-1] == ' ')
351 mp--;
352 break;
353 case 'T': /* Type of list */
354 #if TAGS
355 if (ntags())
356 ap_str("tag");
357 else
358 #endif
359 ap_str("file");
360 break;
361 case 'x': /* Name of next file */
362 h = next_ifile(curr_ifile);
363 if (h != NULL_IFILE)
364 ap_str(get_filename(h));
365 else
366 ap_quest();
367 break;
372 * Skip a false conditional.
373 * When a false condition is found (either a false IF or the ELSE part
374 * of a true IF), this routine scans the prototype string to decide
375 * where to resume parsing the string.
376 * We must keep track of nested IFs and skip them properly.
378 static char *
379 skipcond(p)
380 register char *p;
382 register int iflevel;
385 * We came in here after processing a ? or :,
386 * so we start nested one level deep.
388 iflevel = 1;
390 for (;;) switch (*++p)
392 case '?':
394 * Start of a nested IF.
396 iflevel++;
397 break;
398 case ':':
400 * Else.
401 * If this matches the IF we came in here with,
402 * then we're done.
404 if (iflevel == 1)
405 return (p);
406 break;
407 case '.':
409 * Endif.
410 * If this matches the IF we came in here with,
411 * then we're done.
413 if (--iflevel == 0)
414 return (p);
415 break;
416 case '\\':
418 * Backslash escapes the next character.
420 ++p;
421 break;
422 case '\0':
424 * Whoops. Hit end of string.
425 * This is a malformed conditional, but just treat it
426 * as if all active conditionals ends here.
428 return (p-1);
430 /*NOTREACHED*/
434 * Decode a char that represents a position on the screen.
436 static char *
437 wherechar(p, wp)
438 char *p;
439 int *wp;
441 switch (*p)
443 case 'b': case 'd': case 'l': case 'p': case 'P':
444 switch (*++p)
446 case 't': *wp = TOP; break;
447 case 'm': *wp = MIDDLE; break;
448 case 'b': *wp = BOTTOM; break;
449 case 'B': *wp = BOTTOM_PLUS_ONE; break;
450 case 'j': *wp = adjsline(jump_sline); break;
451 default: *wp = TOP; p--; break;
454 return (p);
458 * Construct a message based on a prototype string.
460 public char *
461 pr_expand(proto, maxwidth)
462 char *proto;
463 int maxwidth;
465 register char *p;
466 register int c;
467 int where;
469 mp = message;
471 if (*proto == '\0')
472 return ("");
474 for (p = proto; *p != '\0'; p++)
476 switch (*p)
478 default: /* Just put the character in the message */
479 ap_char(*p);
480 break;
481 case '\\': /* Backslash escapes the next character */
482 p++;
483 ap_char(*p);
484 break;
485 case '?': /* Conditional (IF) */
486 if ((c = *++p) == '\0')
487 --p;
488 else
490 where = 0;
491 p = wherechar(p, &where);
492 if (!cond(c, where))
493 p = skipcond(p);
495 break;
496 case ':': /* ELSE */
497 p = skipcond(p);
498 break;
499 case '.': /* ENDIF */
500 break;
501 case '%': /* Percent escape */
502 if ((c = *++p) == '\0')
503 --p;
504 else
506 where = 0;
507 p = wherechar(p, &where);
508 protochar(c, where,
509 #if EDITOR
510 (proto == editproto));
511 #else
513 #endif
516 break;
520 if (mp == message)
521 return (NULL);
522 if (maxwidth > 0 && mp >= message + maxwidth)
525 * Message is too long.
526 * Return just the final portion of it.
528 return (mp - maxwidth);
530 return (message);
534 * Return a message suitable for printing by the "=" command.
536 public char *
537 eq_message()
539 return (pr_expand(eqproto, 0));
543 * Return a prompt.
544 * This depends on the prompt type (SHORT, MEDIUM, LONG), etc.
545 * If we can't come up with an appropriate prompt, return NULL
546 * and the caller will prompt with a colon.
548 public char *
549 pr_string()
551 char *prompt;
553 prompt = pr_expand((ch_getflags() & CH_HELPFILE) ?
554 hproto : prproto[pr_type],
555 sc_width-so_s_width-so_e_width-2);
556 new_file = 0;
557 return (prompt);
561 * Return a message suitable for printing while waiting in the F command.
563 public char *
564 wait_message()
566 return (pr_expand(wproto, sc_width-so_s_width-so_e_width-2));