summaryrefslogtreecommitdiffstats
path: root/contrib/less/prompt.c
blob: 14f8ac4253d1a345050c1b261b869936c4f3897d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
/* $FreeBSD$ */
/*
 * Copyright (C) 1984-2000  Mark Nudelman
 *
 * You may distribute under the terms of either the GNU General Public
 * License or the Less License, as specified in the README file.
 *
 * For more information about less, or for information on how to 
 * contact the author, see the README file.
 */


/*
 * Prompting and other messages.
 * There are three flavors of prompts, SHORT, MEDIUM and LONG,
 * selected by the -m/-M options.
 * There is also the "equals message", printed by the = command.
 * A prompt is a message composed of various pieces, such as the 
 * name of the file being viewed, the percentage into the file, etc.
 */

#include "less.h"
#include "position.h"

extern int pr_type;
extern int hit_eof;
extern int new_file;
extern int sc_width;
extern int so_s_width, so_e_width;
extern int linenums;
extern int hshift;
extern int sc_height;
extern int jump_sline;
extern IFILE curr_ifile;
#if EDITOR
extern char *editor;
extern char *editproto;
#endif

/*
 * Prototypes for the three flavors of prompts.
 * These strings are expanded by pr_expand().
 */
static constant char s_proto[] =
  "?n?f%f .?m(file %i of %m) ..?e(END) ?x- Next\\: %x..%t";
static constant char m_proto[] =
  "?n?f%f .?m(file %i of %m) ..?e(END) ?x- Next\\: %x.:?pB%pB\\%:byte %bB?s/%s...%t";
static constant char M_proto[] =
  "?f%f .?n?m(file %i of %m) ..?ltlines %lt-%lb?L/%L. :byte %bB?s/%s. .?e(END) ?x- Next\\: %x.:?pB%pB\\%..%t";
static constant char e_proto[] =
  "?f%f .?m(file %i of %m) .?ltlines %lt-%lb?L/%L. .byte %bB?s/%s. ?e(END) :?pB%pB\\%..%t";
static constant char h_proto[] =
  "HELP -- ?eEND -- Press g to see it again:Press RETURN for more., or q when done";

public char *prproto[3];
public char constant *eqproto = e_proto;
public char constant *hproto = h_proto;

static char message[PROMPT_SIZE];
static char *mp;

/*
 * Initialize the prompt prototype strings.
 */
	public void
init_prompt()
{
	prproto[0] = save(s_proto);
	prproto[1] = save(m_proto);
	prproto[2] = save(M_proto);
	eqproto = save(e_proto);
	hproto = save(h_proto);
}

/*
 * Append a string to the end of the message.
 */
	static void
ap_str(s)
	char *s;
{
	int len;

	len = strlen(s);
	if (mp + len >= message + PROMPT_SIZE)
		len = message + PROMPT_SIZE - mp - 1;
	strncpy(mp, s, len);
	mp += len;
	*mp = '\0';
}

/*
 * Append a character to the end of the message.
 */
	static void
ap_char(c)
	char c;
{
	char buf[2];

	buf[0] = c;
	buf[1] = '\0';
	ap_str(buf);
}

/*
 * Append a POSITION (as a decimal integer) to the end of the message.
 */
	static void
ap_pos(pos)
	POSITION pos;
{
	char buf[MAX_PRINT_POSITION];

	sprintf(buf, PR_POSITION, (long long)pos);
	ap_str(buf);
}

/*
 * Append an integer to the end of the message.
 */
	static void
ap_int(n)
	int n;
{
	char buf[MAX_PRINT_INT];

	sprintf(buf, "%d", n);
	ap_str(buf);
}

/*
 * Append a question mark to the end of the message.
 */
	static void
ap_quest()
{
	ap_str("?");
}

/*
 * Return the "current" byte offset in the file.
 */
	static POSITION
curr_byte(where)
	int where;
{
	POSITION pos;

	pos = position(where);
	while (pos == NULL_POSITION && where >= 0 && where < sc_height)
		pos = position(++where);
	if (pos == NULL_POSITION)
		pos = ch_length();
	return (pos);
}

/*
 * Return the value of a prototype conditional.
 * A prototype string may include conditionals which consist of a 
 * question mark followed by a single letter.
 * Here we decode that letter and return the appropriate boolean value.
 */
	static int
cond(c, where)
	char c;
	int where;
{
	POSITION len;

	switch (c)
	{
	case 'a':	/* Anything in the message yet? */
		return (mp > message);
	case 'b':	/* Current byte offset known? */
		return (curr_byte(where) != NULL_POSITION);
	case 'c':
		return (hshift != 0);
	case 'e':	/* At end of file? */
		return (hit_eof);
	case 'f':	/* Filename known? */
		return (strcmp(get_filename(curr_ifile), "-") != 0);
	case 'l':	/* Line number known? */
	case 'd':	/* Same as l */
		return (linenums);
	case 'L':	/* Final line number known? */
	case 'D':	/* Same as L */
		return (linenums && ch_length() != NULL_POSITION);
	case 'm':	/* More than one file? */
		return (nifile() > 1);
	case 'n':	/* First prompt in a new file? */
		return (new_file);
	case 'p':	/* Percent into file (bytes) known? */
		return (curr_byte(where) != NULL_POSITION && 
				ch_length() > 0);
	case 'P':	/* Percent into file (lines) known? */
		return (currline(where) != 0 &&
				(len = ch_length()) > 0 &&
				find_linenum(len) != 0);
	case 's':	/* Size of file known? */
	case 'B':
		return (ch_length() != NULL_POSITION);
	case 'x':	/* Is there a "next" file? */
		return (next_ifile(curr_ifile) != NULL_IFILE);
	}
	return (0);
}

/*
 * Decode a "percent" prototype character.
 * A prototype string may include various "percent" escapes;
 * that is, a percent sign followed by a single letter.
 * Here we decode that letter and take the appropriate action,
 * usually by appending something to the message being built.
 */
	static void
protochar(c, where, iseditproto)
	int c;
	int where;
	int iseditproto;
{
	POSITION pos;
	POSITION len;
	int n;
	IFILE h;
	char *s;
	char *escs;

	switch (c)
	{
	case 'b':	/* Current byte offset */
		pos = curr_byte(where);
		if (pos != NULL_POSITION)
			ap_pos(pos);
		else
			ap_quest();
		break;
	case 'c':
		ap_int(hshift);
		break;
	case 'd':	/* Current page number */
		n = currline(where);
		if (n > 0 && sc_height > 1)
			ap_int(((n - 1) / (sc_height - 1)) + 1);
		else
			ap_quest();
		break;
	case 'D':	/* Last page number */
		len = ch_length();
		if (len == NULL_POSITION || len == ch_zero() ||
		    (n = find_linenum(len)) <= 0)
			ap_quest();
		else
			ap_int(((n - 1) / (sc_height - 1)) + 1);
		break;
#if EDITOR
	case 'E':	/* Editor name */
		ap_str(editor);
		break;
#endif
	case 'f':	/* File name */
		s = unquote_file(get_filename(curr_ifile));
		/*
		 * If we are expanding editproto then we escape metachars.
		 * This allows us to run the editor on files with funny names.
		 */
		if (iseditproto && (escs = esc_metachars(s)) != NULL)
		{
			free(s);
			s = escs;
		}
		ap_str(s);
		free(s);
		break;
	case 'i':	/* Index into list of files */
		ap_int(get_index(curr_ifile));
		break;
	case 'l':	/* Current line number */
		n = currline(where);
		if (n != 0)
			ap_int(n);
		else
			ap_quest();
		break;
	case 'L':	/* Final line number */
		len = ch_length();
		if (len == NULL_POSITION || len == ch_zero() ||
		    (n = find_linenum(len)) <= 0)
			ap_quest();
		else
			ap_int(n-1);
		break;
	case 'm':	/* Number of files */
		ap_int(nifile());
		break;
	case 'p':	/* Percent into file (bytes) */
		pos = curr_byte(where);
		len = ch_length();
		if (pos != NULL_POSITION && len > 0)
			ap_int(percentage(pos,len));
		else
			ap_quest();
		break;
	case 'P':	/* Percent into file (lines) */
		pos = (POSITION) currline(where);
		if (pos == 0 ||
		    (len = ch_length()) == NULL_POSITION || len == ch_zero() ||
		    (n = find_linenum(len)) <= 0)
			ap_quest();
		else
			ap_int(percentage(pos, (POSITION)n));
		break;
	case 's':	/* Size of file */
	case 'B':
		len = ch_length();
		if (len != NULL_POSITION)
			ap_pos(len);
		else
			ap_quest();
		break;
	case 't':	/* Truncate trailing spaces in the message */
		while (mp > message && mp[-1] == ' ')
			mp--;
		break;
	case 'x':	/* Name of next file */
		h = next_ifile(curr_ifile);
		if (h != NULL_IFILE)
		{
			s = unquote_file(get_filename(h));
			ap_str(s);
			free(s);
		} else
			ap_quest();
		break;
	}
}

/*
 * Skip a false conditional.
 * When a false condition is found (either a false IF or the ELSE part 
 * of a true IF), this routine scans the prototype string to decide
 * where to resume parsing the string.
 * We must keep track of nested IFs and skip them properly.
 */
	static char *
skipcond(p)
	register char *p;
{
	register int iflevel;

	/*
	 * We came in here after processing a ? or :,
	 * so we start nested one level deep.
	 */
	iflevel = 1;

	for (;;) switch (*++p)
	{
	case '?':
		/*
		 * Start of a nested IF.
		 */
		iflevel++;
		break;
	case ':':
		/*
		 * Else.
		 * If this matches the IF we came in here with,
		 * then we're done.
		 */
		if (iflevel == 1)
			return (p);
		break;
	case '.':
		/*
		 * Endif.
		 * If this matches the IF we came in here with,
		 * then we're done.
		 */
		if (--iflevel == 0)
			return (p);
		break;
	case '\\':
		/*
		 * Backslash escapes the next character.
		 */
		++p;
		break;
	case '\0':
		/*
		 * Whoops.  Hit end of string.
		 * This is a malformed conditional, but just treat it
		 * as if all active conditionals ends here.
		 */
		return (p-1);
	}
	/*NOTREACHED*/
}

/*
 * Decode a char that represents a position on the screen.
 */
	static char *
wherechar(p, wp)
	char *p;
	int *wp;
{
	switch (*p)
	{
	case 'b': case 'd': case 'l': case 'p': case 'P':
		switch (*++p)
		{
		case 't':   *wp = TOP;			break;
		case 'm':   *wp = MIDDLE;		break;
		case 'b':   *wp = BOTTOM;		break;
		case 'B':   *wp = BOTTOM_PLUS_ONE;	break;
		case 'j':   *wp = adjsline(jump_sline);	break;
		default:    *wp = TOP;  p--;		break;
		}
	}
	return (p);
}

/*
 * Construct a message based on a prototype string.
 */
	public char *
pr_expand(proto, maxwidth)
	char *proto;
	int maxwidth;
{
	register char *p;
	register int c;
	int where;

	mp = message;

	if (*proto == '\0')
		return ("");

	for (p = proto;  *p != '\0';  p++)
	{
		switch (*p)
		{
		default:	/* Just put the character in the message */
			ap_char(*p);
			break;
		case '\\':	/* Backslash escapes the next character */
			p++;
			ap_char(*p);
			break;
		case '?':	/* Conditional (IF) */
			if ((c = *++p) == '\0')
				--p;
			else
			{
				where = 0;
				p = wherechar(p, &where);
				if (!cond(c, where))
					p = skipcond(p);
			}
			break;
		case ':':	/* ELSE */
			p = skipcond(p);
			break;
		case '.':	/* ENDIF */
			break;
		case '%':	/* Percent escape */
			if ((c = *++p) == '\0')
				--p;
			else
			{
				where = 0;
				p = wherechar(p, &where);
				protochar(c, where,
#if EDITOR
					(proto == editproto));
#else
					0);
#endif

			}
			break;
		}
	}

	new_file = 0;
	if (mp == message)
		return (NULL);
	if (maxwidth > 0 && mp >= message + maxwidth)
	{
		/*
		 * Message is too long.
		 * Return just the final portion of it.
		 */
		return (mp - maxwidth);
	}
	return (message);
}

/*
 * Return a message suitable for printing by the "=" command.
 */
	public char *
eq_message()
{
	return (pr_expand(eqproto, 0));
}

/*
 * Return a prompt.
 * This depends on the prompt type (SHORT, MEDIUM, LONG), etc.
 * If we can't come up with an appropriate prompt, return NULL
 * and the caller will prompt with a colon.
 */
	public char *
pr_string()
{
	if (ch_getflags() & CH_HELPFILE)
		return (pr_expand(hproto, sc_width-so_s_width-so_e_width-2));
	return (pr_expand(prproto[pr_type], sc_width-so_s_width-so_e_width-2));
}
OpenPOWER on IntegriCloud