summaryrefslogtreecommitdiffstats
path: root/usr.bin/grep/file.c
blob: 81f227d80739d6040b4710106a14076bdee20bcb (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
/*	$NetBSD: file.c,v 1.5 2011/02/16 18:35:39 joerg Exp $	*/
/*	$FreeBSD$	*/
/*	$OpenBSD: file.c,v 1.11 2010/07/02 20:48:48 nicm Exp $	*/

/*-
 * Copyright (c) 1999 James Howard and Dag-Erling Coïdan Smørgrav
 * Copyright (C) 2008-2010 Gabor Kovesdan <gabor@FreeBSD.org>
 * Copyright (C) 2010 Dimitry Andric <dimitry@andric.com>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

#include <sys/param.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/types.h>

#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <wchar.h>
#include <wctype.h>
#include <zlib.h>

#ifndef WITHOUT_LZMA
#include <lzma.h>
#endif

#ifndef WITHOUT_BZIP2
#include <bzlib.h>
#endif

#include "grep.h"

#define	MAXBUFSIZ	(32 * 1024)
#define	LNBUFBUMP	80

static gzFile gzbufdesc;
#ifndef WITHOUT_LZMA
static lzma_stream lstrm = LZMA_STREAM_INIT;
static lzma_action laction;
static uint8_t lin_buf[MAXBUFSIZ];
#endif
#ifndef WITHOUT_BZIP2
static BZFILE* bzbufdesc;
#endif

static unsigned char *buffer;
static unsigned char *bufpos;
static size_t bufrem;
static size_t fsiz;

static unsigned char *lnbuf;
static size_t lnbuflen;

static inline int
grep_refill(struct file *f)
{
	ssize_t nr;

	if (filebehave == FILE_MMAP)
		return (0);

	bufpos = buffer;
	bufrem = 0;

	if (filebehave == FILE_GZIP) {
		nr = gzread(gzbufdesc, buffer, MAXBUFSIZ);
#ifndef WITHOUT_BZIP2
	} else if (filebehave == FILE_BZIP && bzbufdesc != NULL) {
		int bzerr;

		nr = BZ2_bzRead(&bzerr, bzbufdesc, buffer, MAXBUFSIZ);
		switch (bzerr) {
		case BZ_OK:
		case BZ_STREAM_END:
			/* No problem, nr will be okay */
			break;
		case BZ_DATA_ERROR_MAGIC:
			/*
			 * As opposed to gzread(), which simply returns the
			 * plain file data, if it is not in the correct
			 * compressed format, BZ2_bzRead() instead aborts.
			 *
			 * So, just restart at the beginning of the file again,
			 * and use plain reads from now on.
			 */
			BZ2_bzReadClose(&bzerr, bzbufdesc);
			bzbufdesc = NULL;
			if (lseek(f->fd, 0, SEEK_SET) == -1)
				return (-1);
			nr = read(f->fd, buffer, MAXBUFSIZ);
			break;
		default:
			/* Make sure we exit with an error */
			nr = -1;
		}
#endif
#ifndef WITHOUT_LZMA
	} else if ((filebehave == FILE_XZ) || (filebehave == FILE_LZMA)) {
		lzma_ret ret;
		lstrm.next_out = buffer;

		do {
			if (lstrm.avail_in == 0) {
				lstrm.next_in = lin_buf;
				nr = read(f->fd, lin_buf, MAXBUFSIZ);

				if (nr < 0)
					return (-1);
				else if (nr == 0)
					laction = LZMA_FINISH;

				lstrm.avail_in = nr;
			}

			ret = lzma_code(&lstrm, laction);

			if (ret != LZMA_OK && ret != LZMA_STREAM_END)
				return (-1);

			if (lstrm.avail_out == 0 || ret == LZMA_STREAM_END) {
				bufrem = MAXBUFSIZ - lstrm.avail_out;
				lstrm.next_out = buffer;
				lstrm.avail_out = MAXBUFSIZ;
			}
		} while (bufrem == 0 && ret != LZMA_STREAM_END);

		return (0);
#endif	/* WIHTOUT_LZMA */
	} else
		nr = read(f->fd, buffer, MAXBUFSIZ);

	if (nr < 0)
		return (-1);

	bufrem = nr;
	return (0);
}

static inline int
grep_lnbufgrow(size_t newlen)
{

	if (lnbuflen < newlen) {
		lnbuf = grep_realloc(lnbuf, newlen);
		lnbuflen = newlen;
	}

	return (0);
}

char *
grep_fgetln(struct file *f, size_t *lenp)
{
	unsigned char *p;
	char *ret;
	size_t len;
	size_t off;
	ptrdiff_t diff;

	/* Fill the buffer, if necessary */
	if (bufrem == 0 && grep_refill(f) != 0)
		goto error;

	if (bufrem == 0) {
		/* Return zero length to indicate EOF */
		*lenp = 0;
		return (bufpos);
	}

	/* Look for a newline in the remaining part of the buffer */
	if ((p = memchr(bufpos, '\n', bufrem)) != NULL) {
		++p; /* advance over newline */
		ret = bufpos;
		len = p - bufpos;
		bufrem -= len;
		bufpos = p;
		*lenp = len;
		return (ret);
	}

	/* We have to copy the current buffered data to the line buffer */
	for (len = bufrem, off = 0; ; len += bufrem) {
		/* Make sure there is room for more data */
		if (grep_lnbufgrow(len + LNBUFBUMP))
			goto error;
		memcpy(lnbuf + off, bufpos, len - off);
		off = len;
		if (grep_refill(f) != 0)
			goto error;
		if (bufrem == 0)
			/* EOF: return partial line */
			break;
		if ((p = memchr(bufpos, '\n', bufrem)) == NULL)
			continue;
		/* got it: finish up the line (like code above) */
		++p;
		diff = p - bufpos;
		len += diff;
		if (grep_lnbufgrow(len))
		    goto error;
		memcpy(lnbuf + off, bufpos, diff);
		bufrem -= diff;
		bufpos = p;
		break;
	}
	*lenp = len;
	return (lnbuf);

error:
	*lenp = 0;
	return (NULL);
}

/*
 * Opens a file for processing.
 */
struct file *
grep_open(const char *path)
{
	struct file *f;

	f = grep_malloc(sizeof *f);
	memset(f, 0, sizeof *f);
	if (path == NULL) {
		/* Processing stdin implies --line-buffered. */
		lbflag = true;
		f->fd = STDIN_FILENO;
	} else if ((f->fd = open(path, O_RDONLY)) == -1)
		goto error1;

	if (filebehave == FILE_MMAP) {
		struct stat st;

		if ((fstat(f->fd, &st) == -1) || (st.st_size > OFF_MAX) ||
		    (!S_ISREG(st.st_mode)))
			filebehave = FILE_STDIO;
		else {
			int flags = MAP_PRIVATE | MAP_NOCORE | MAP_NOSYNC;
#ifdef MAP_PREFAULT_READ
			flags |= MAP_PREFAULT_READ;
#endif
			fsiz = st.st_size;
			buffer = mmap(NULL, fsiz, PROT_READ, flags,
			     f->fd, (off_t)0);
			if (buffer == MAP_FAILED)
				filebehave = FILE_STDIO;
			else {
				bufrem = st.st_size;
				bufpos = buffer;
				madvise(buffer, st.st_size, MADV_SEQUENTIAL);
			}
		}
	}

	if ((buffer == NULL) || (buffer == MAP_FAILED))
		buffer = grep_malloc(MAXBUFSIZ);

	if (filebehave == FILE_GZIP &&
	    (gzbufdesc = gzdopen(f->fd, "r")) == NULL)
		goto error2;

#ifndef WITHOUT_BZIP2
	if (filebehave == FILE_BZIP &&
	    (bzbufdesc = BZ2_bzdopen(f->fd, "r")) == NULL)
		goto error2;
#endif
#ifndef WITHOUT_LZMA
	else if ((filebehave == FILE_XZ) || (filebehave == FILE_LZMA)) {
		lzma_ret ret;

		ret = (filebehave == FILE_XZ) ?
			lzma_stream_decoder(&lstrm, UINT64_MAX,
					LZMA_CONCATENATED) :
			lzma_alone_decoder(&lstrm, UINT64_MAX);

		if (ret != LZMA_OK)
			goto error2;

		lstrm.avail_in = 0;
		lstrm.avail_out = MAXBUFSIZ;
		laction = LZMA_RUN;
	}
#endif

	/* Fill read buffer, also catches errors early */
	if (bufrem == 0 && grep_refill(f) != 0)
		goto error2;

	/* Check for binary stuff, if necessary */
	if (binbehave != BINFILE_TEXT && memchr(bufpos, '\0', bufrem) != NULL)
	f->binary = true;

	return (f);

error2:
	close(f->fd);
error1:
	free(f);
	return (NULL);
}

/*
 * Closes a file.
 */
void
grep_close(struct file *f)
{

	close(f->fd);

	/* Reset read buffer and line buffer */
	if (filebehave == FILE_MMAP) {
		munmap(buffer, fsiz);
		buffer = NULL;
	}
	bufpos = buffer;
	bufrem = 0;

	free(lnbuf);
	lnbuf = NULL;
	lnbuflen = 0;
}
OpenPOWER on IntegriCloud