summaryrefslogtreecommitdiffstats
path: root/quote.c
blob: 26719d21d1e7555d92289b26402a73030e330606 (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
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
#include "cache.h"
#include "quote.h"
#include "strvec.h"

int quote_path_fully = 1;

static inline int need_bs_quote(char c)
{
	return (c == '\'' || c == '!');
}

/* Help to copy the thing properly quoted for the shell safety.
 * any single quote is replaced with '\'', any exclamation point
 * is replaced with '\!', and the whole thing is enclosed in a
 * single quote pair.
 *
 * E.g.
 *  original     sq_quote     result
 *  name     ==> name      ==> 'name'
 *  a b      ==> a b       ==> 'a b'
 *  a'b      ==> a'\''b    ==> 'a'\''b'
 *  a!b      ==> a'\!'b    ==> 'a'\!'b'
 */
void sq_quote_buf(struct strbuf *dst, const char *src)
{
	char *to_free = NULL;

	if (dst->buf == src)
		to_free = strbuf_detach(dst, NULL);

	strbuf_addch(dst, '\'');
	while (*src) {
		size_t len = strcspn(src, "'!");
		strbuf_add(dst, src, len);
		src += len;
		while (need_bs_quote(*src)) {
			strbuf_addstr(dst, "'\\");
			strbuf_addch(dst, *src++);
			strbuf_addch(dst, '\'');
		}
	}
	strbuf_addch(dst, '\'');
	free(to_free);
}

void sq_quote_buf_pretty(struct strbuf *dst, const char *src)
{
	static const char ok_punct[] = "+,-./:=@_^";
	const char *p;

	/* Avoid losing a zero-length string by adding '' */
	if (!*src) {
		strbuf_addstr(dst, "''");
		return;
	}

	for (p = src; *p; p++) {
		if (!isalnum(*p) && !strchr(ok_punct, *p)) {
			sq_quote_buf(dst, src);
			return;
		}
	}

	/* if we get here, we did not need quoting */
	strbuf_addstr(dst, src);
}

void sq_quotef(struct strbuf *dst, const char *fmt, ...)
{
	struct strbuf src = STRBUF_INIT;

	va_list ap;
	va_start(ap, fmt);
	strbuf_vaddf(&src, fmt, ap);
	va_end(ap);

	sq_quote_buf(dst, src.buf);
	strbuf_release(&src);
}

void sq_quote_argv(struct strbuf *dst, const char **argv)
{
	int i;

	/* Copy into destination buffer. */
	strbuf_grow(dst, 255);
	for (i = 0; argv[i]; ++i) {
		strbuf_addch(dst, ' ');
		sq_quote_buf(dst, argv[i]);
	}
}

/*
 * Legacy function to append each argv value, quoted as necessasry,
 * with whitespace before each value.  This results in a leading
 * space in the result.
 */
void sq_quote_argv_pretty(struct strbuf *dst, const char **argv)
{
	if (argv[0])
		strbuf_addch(dst, ' ');
	sq_append_quote_argv_pretty(dst, argv);
}

/*
 * Append each argv value, quoted as necessary, with whitespace between them.
 */
void sq_append_quote_argv_pretty(struct strbuf *dst, const char **argv)
{
	int i;

	for (i = 0; argv[i]; i++) {
		if (i > 0)
			strbuf_addch(dst, ' ');
		sq_quote_buf_pretty(dst, argv[i]);
	}
}

char *sq_dequote_step(char *arg, char **next)
{
	char *dst = arg;
	char *src = arg;
	char c;

	if (*src != '\'')
		return NULL;
	for (;;) {
		c = *++src;
		if (!c)
			return NULL;
		if (c != '\'') {
			*dst++ = c;
			continue;
		}
		/* We stepped out of sq */
		switch (*++src) {
		case '\0':
			*dst = 0;
			if (next)
				*next = NULL;
			return arg;
		case '\\':
			/*
			 * Allow backslashed characters outside of
			 * single-quotes only if they need escaping,
			 * and only if we resume the single-quoted part
			 * afterward.
			 */
			if (need_bs_quote(src[1]) && src[2] == '\'') {
				*dst++ = src[1];
				src += 2;
				continue;
			}
		/* Fallthrough */
		default:
			if (!next)
				return NULL;
			*dst = 0;
			*next = src;
			return arg;
		}
	}
}

char *sq_dequote(char *arg)
{
	return sq_dequote_step(arg, NULL);
}

static int sq_dequote_to_argv_internal(char *arg,
				       const char ***argv, int *nr, int *alloc,
				       struct strvec *array)
{
	char *next = arg;

	if (!*arg)
		return 0;
	do {
		char *dequoted = sq_dequote_step(next, &next);
		if (!dequoted)
			return -1;
		if (next) {
			char c;
			if (!isspace(*next))
				return -1;
			do {
				c = *++next;
			} while (isspace(c));
		}
		if (argv) {
			ALLOC_GROW(*argv, *nr + 1, *alloc);
			(*argv)[(*nr)++] = dequoted;
		}
		if (array)
			strvec_push(array, dequoted);
	} while (next);

	return 0;
}

int sq_dequote_to_argv(char *arg, const char ***argv, int *nr, int *alloc)
{
	return sq_dequote_to_argv_internal(arg, argv, nr, alloc, NULL);
}

int sq_dequote_to_strvec(char *arg, struct strvec *array)
{
	return sq_dequote_to_argv_internal(arg, NULL, NULL, NULL, array);
}

/* 1 means: quote as octal
 * 0 means: quote as octal if (quote_path_fully)
 * -1 means: never quote
 * c: quote as "\\c"
 */
#define X8(x)   x, x, x, x, x, x, x, x
#define X16(x)  X8(x), X8(x)
static signed char const cq_lookup[256] = {
	/*           0    1    2    3    4    5    6    7 */
	/* 0x00 */   1,   1,   1,   1,   1,   1,   1, 'a',
	/* 0x08 */ 'b', 't', 'n', 'v', 'f', 'r',   1,   1,
	/* 0x10 */ X16(1),
	/* 0x20 */  -1,  -1, '"',  -1,  -1,  -1,  -1,  -1,
	/* 0x28 */ X16(-1), X16(-1), X16(-1),
	/* 0x58 */  -1,  -1,  -1,  -1,'\\',  -1,  -1,  -1,
	/* 0x60 */ X16(-1), X8(-1),
	/* 0x78 */  -1,  -1,  -1,  -1,  -1,  -1,  -1,   1,
	/* 0x80 */ /* set to 0 */
};

static inline int cq_must_quote(char c)
{
	return cq_lookup[(unsigned char)c] + quote_path_fully > 0;
}

/* returns the longest prefix not needing a quote up to maxlen if positive.
   This stops at the first \0 because it's marked as a character needing an
   escape */
static size_t next_quote_pos(const char *s, ssize_t maxlen)
{
	size_t len;
	if (maxlen < 0) {
		for (len = 0; !cq_must_quote(s[len]); len++);
	} else {
		for (len = 0; len < maxlen && !cq_must_quote(s[len]); len++);
	}
	return len;
}

/*
 * C-style name quoting.
 *
 * (1) if sb and fp are both NULL, inspect the input name and counts the
 *     number of bytes that are needed to hold c_style quoted version of name,
 *     counting the double quotes around it but not terminating NUL, and
 *     returns it.
 *     However, if name does not need c_style quoting, it returns 0.
 *
 * (2) if sb or fp are not NULL, it emits the c_style quoted version
 *     of name, enclosed with double quotes if asked and needed only.
 *     Return value is the same as in (1).
 */
static size_t quote_c_style_counted(const char *name, ssize_t maxlen,
				    struct strbuf *sb, FILE *fp, unsigned flags)
{
#undef EMIT
#define EMIT(c)                                 \
	do {                                        \
		if (sb) strbuf_addch(sb, (c));          \
		if (fp) fputc((c), fp);                 \
		count++;                                \
	} while (0)
#define EMITBUF(s, l)                           \
	do {                                        \
		if (sb) strbuf_add(sb, (s), (l));       \
		if (fp) fwrite((s), (l), 1, fp);        \
		count += (l);                           \
	} while (0)

	int no_dq = !!(flags & CQUOTE_NODQ);
	size_t len, count = 0;
	const char *p = name;

	for (;;) {
		int ch;

		len = next_quote_pos(p, maxlen);
		if (len == maxlen || (maxlen < 0 && !p[len]))
			break;

		if (!no_dq && p == name)
			EMIT('"');

		EMITBUF(p, len);
		EMIT('\\');
		p += len;
		ch = (unsigned char)*p++;
		if (maxlen >= 0)
			maxlen -= len + 1;
		if (cq_lookup[ch] >= ' ') {
			EMIT(cq_lookup[ch]);
		} else {
			EMIT(((ch >> 6) & 03) + '0');
			EMIT(((ch >> 3) & 07) + '0');
			EMIT(((ch >> 0) & 07) + '0');
		}
	}

	EMITBUF(p, len);
	if (p == name)   /* no ending quote needed */
		return 0;

	if (!no_dq)
		EMIT('"');
	return count;
}

size_t quote_c_style(const char *name, struct strbuf *sb, FILE *fp, unsigned flags)
{
	return quote_c_style_counted(name, -1, sb, fp, flags);
}

void quote_two_c_style(struct strbuf *sb, const char *prefix, const char *path,
		       unsigned flags)
{
	int nodq = !!(flags & CQUOTE_NODQ);
	if (quote_c_style(prefix, NULL, NULL, 0) ||
	    quote_c_style(path, NULL, NULL, 0)) {
		if (!nodq)
			strbuf_addch(sb, '"');
		quote_c_style(prefix, sb, NULL, CQUOTE_NODQ);
		quote_c_style(path, sb, NULL, CQUOTE_NODQ);
		if (!nodq)
			strbuf_addch(sb, '"');
	} else {
		strbuf_addstr(sb, prefix);
		strbuf_addstr(sb, path);
	}
}

void write_name_quoted(const char *name, FILE *fp, int terminator)
{
	if (terminator) {
		quote_c_style(name, NULL, fp, 0);
	} else {
		fputs(name, fp);
	}
	fputc(terminator, fp);
}

void write_name_quoted_relative(const char *name, const char *prefix,
				FILE *fp, int terminator)
{
	struct strbuf sb = STRBUF_INIT;

	name = relative_path(name, prefix, &sb);
	write_name_quoted(name, fp, terminator);

	strbuf_release(&sb);
}

/* quote path as relative to the given prefix */
char *quote_path(const char *in, const char *prefix, struct strbuf *out, unsigned flags)
{
	struct strbuf sb = STRBUF_INIT;
	const char *rel = relative_path(in, prefix, &sb);
	int force_dq = ((flags & QUOTE_PATH_QUOTE_SP) && strchr(rel, ' '));

	strbuf_reset(out);

	/*
	 * If the caller wants us to enclose the output in a dq-pair
	 * whether quote_c_style_counted() needs to, we do it ourselves
	 * and tell quote_c_style_counted() not to.
	 */
	if (force_dq)
		strbuf_addch(out, '"');
	quote_c_style_counted(rel, strlen(rel), out, NULL,
			      force_dq ? CQUOTE_NODQ : 0);
	if (force_dq)
		strbuf_addch(out, '"');
	strbuf_release(&sb);

	return out->buf;
}

/*
 * C-style name unquoting.
 *
 * Quoted should point at the opening double quote.
 * + Returns 0 if it was able to unquote the string properly, and appends the
 *   result in the strbuf `sb'.
 * + Returns -1 in case of error, and doesn't touch the strbuf. Though note
 *   that this function will allocate memory in the strbuf, so calling
 *   strbuf_release is mandatory whichever result unquote_c_style returns.
 *
 * Updates endp pointer to point at one past the ending double quote if given.
 */
int unquote_c_style(struct strbuf *sb, const char *quoted, const char **endp)
{
	size_t oldlen = sb->len, len;
	int ch, ac;

	if (*quoted++ != '"')
		return -1;

	for (;;) {
		len = strcspn(quoted, "\"\\");
		strbuf_add(sb, quoted, len);
		quoted += len;

		switch (*quoted++) {
		  case '"':
			if (endp)
				*endp = quoted;
			return 0;
		  case '\\':
			break;
		  default:
			goto error;
		}

		switch ((ch = *quoted++)) {
		case 'a': ch = '\a'; break;
		case 'b': ch = '\b'; break;
		case 'f': ch = '\f'; break;
		case 'n': ch = '\n'; break;
		case 'r': ch = '\r'; break;
		case 't': ch = '\t'; break;
		case 'v': ch = '\v'; break;

		case '\\': case '"':
			break; /* verbatim */

		/* octal values with first digit over 4 overflow */
		case '0': case '1': case '2': case '3':
					ac = ((ch - '0') << 6);
			if ((ch = *quoted++) < '0' || '7' < ch)
				goto error;
					ac |= ((ch - '0') << 3);
			if ((ch = *quoted++) < '0' || '7' < ch)
				goto error;
					ac |= (ch - '0');
					ch = ac;
					break;
				default:
			goto error;
			}
		strbuf_addch(sb, ch);
		}

  error:
	strbuf_setlen(sb, oldlen);
	return -1;
}

/* quoting as a string literal for other languages */

void perl_quote_buf(struct strbuf *sb, const char *src)
{
	const char sq = '\'';
	const char bq = '\\';
	char c;

	strbuf_addch(sb, sq);
	while ((c = *src++)) {
		if (c == sq || c == bq)
			strbuf_addch(sb, bq);
		strbuf_addch(sb, c);
	}
	strbuf_addch(sb, sq);
}

void perl_quote_buf_with_len(struct strbuf *sb, const char *src, size_t len)
{
	const char sq = '\'';
	const char bq = '\\';
	const char *c = src;
	const char *end = src + len;

	strbuf_addch(sb, sq);
	while (c != end) {
		if (*c == sq || *c == bq)
			strbuf_addch(sb, bq);
		strbuf_addch(sb, *c);
		c++;
	}
	strbuf_addch(sb, sq);
}

void python_quote_buf(struct strbuf *sb, const char *src)
{
	const char sq = '\'';
	const char bq = '\\';
	const char nl = '\n';
	char c;

	strbuf_addch(sb, sq);
	while ((c = *src++)) {
		if (c == nl) {
			strbuf_addch(sb, bq);
			strbuf_addch(sb, 'n');
			continue;
		}
		if (c == sq || c == bq)
			strbuf_addch(sb, bq);
		strbuf_addch(sb, c);
	}
	strbuf_addch(sb, sq);
}

void tcl_quote_buf(struct strbuf *sb, const char *src)
{
	char c;

	strbuf_addch(sb, '"');
	while ((c = *src++)) {
		switch (c) {
		case '[': case ']':
		case '{': case '}':
		case '$': case '\\': case '"':
			strbuf_addch(sb, '\\');
			/* fallthrough */
		default:
			strbuf_addch(sb, c);
			break;
		case '\f':
			strbuf_addstr(sb, "\\f");
			break;
		case '\r':
			strbuf_addstr(sb, "\\r");
			break;
		case '\n':
			strbuf_addstr(sb, "\\n");
			break;
		case '\t':
			strbuf_addstr(sb, "\\t");
			break;
		case '\v':
			strbuf_addstr(sb, "\\v");
			break;
		}
	}
	strbuf_addch(sb, '"');
}

void basic_regex_quote_buf(struct strbuf *sb, const char *src)
{
	char c;

	if (*src == '^') {
		/* only beginning '^' is special and needs quoting */
		strbuf_addch(sb, '\\');
		strbuf_addch(sb, *src++);
	}
	if (*src == '*')
		/* beginning '*' is not special, no quoting */
		strbuf_addch(sb, *src++);

	while ((c = *src++)) {
		switch (c) {
		case '[':
		case '.':
		case '\\':
		case '*':
			strbuf_addch(sb, '\\');
			strbuf_addch(sb, c);
			break;

		case '$':
			/* only the end '$' is special and needs quoting */
			if (*src == '\0')
				strbuf_addch(sb, '\\');
			strbuf_addch(sb, c);
			break;

		default:
			strbuf_addch(sb, c);
			break;
		}
	}
}