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1 /*	$NetBSD: file.c,v 1.7 2011/04/18 22:46:48 joerg Exp $	*/
2 /*	$FreeBSD: head/usr.bin/grep/file.c 211496 2010-08-19 09:28:59Z des $	*/
3 /*	$OpenBSD: file.c,v 1.11 2010/07/02 20:48:48 nicm Exp $	*/
4 
5 /*-
6  * Copyright (c) 1999 James Howard and Dag-Erling Coïdan Smørgrav
7  * Copyright (C) 2008-2010 Gabor Kovesdan <gabor@FreeBSD.org>
8  * Copyright (C) 2010 Dimitry Andric <dimitry@andric.com>
9  * All rights reserved.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 #if HAVE_NBTOOL_CONFIG_H
34 #include "nbtool_config.h"
35 #endif
36 
37 #include <sys/cdefs.h>
38 __RCSID("$NetBSD: file.c,v 1.7 2011/04/18 22:46:48 joerg Exp $");
39 
40 #include <sys/param.h>
41 #include <sys/types.h>
42 #include <sys/stat.h>
43 
44 #ifndef __ANDROID__
45 #include <bzlib.h>
46 #endif
47 #include <err.h>
48 #include <errno.h>
49 #include <fcntl.h>
50 #include <stddef.h>
51 #include <stdlib.h>
52 #include <string.h>
53 #include <unistd.h>
54 #include <wchar.h>
55 #include <wctype.h>
56 #ifndef __ANDROID__
57 #include <zlib.h>
58 #endif
59 
60 #include "grep.h"
61 
62 #define	MAXBUFSIZ	(32 * 1024)
63 #define	LNBUFBUMP	80
64 
65 #ifndef __ANDROID__
66 static gzFile gzbufdesc;
67 static BZFILE* bzbufdesc;
68 #endif
69 
70 static unsigned char buffer[MAXBUFSIZ];
71 static unsigned char *bufpos;
72 static size_t bufrem;
73 
74 static unsigned char *lnbuf;
75 static size_t lnbuflen;
76 
77 static inline int
grep_refill(struct file * f)78 grep_refill(struct file *f)
79 {
80 	ssize_t nr;
81 #ifndef __ANDROID__
82 	int bzerr;
83 #endif
84 
85 	bufpos = buffer;
86 	bufrem = 0;
87 
88 #ifndef __ANDROID__
89 	if (filebehave == FILE_GZIP)
90 		nr = gzread(gzbufdesc, buffer, MAXBUFSIZ);
91 	else if (filebehave == FILE_BZIP && bzbufdesc != NULL) {
92 		nr = BZ2_bzRead(&bzerr, bzbufdesc, buffer, MAXBUFSIZ);
93 		switch (bzerr) {
94 		case BZ_OK:
95 		case BZ_STREAM_END:
96 			/* No problem, nr will be okay */
97 			break;
98 		case BZ_DATA_ERROR_MAGIC:
99 			/*
100 			 * As opposed to gzread(), which simply returns the
101 			 * plain file data, if it is not in the correct
102 			 * compressed format, BZ2_bzRead() instead aborts.
103 			 *
104 			 * So, just restart at the beginning of the file again,
105 			 * and use plain reads from now on.
106 			 */
107 			BZ2_bzReadClose(&bzerr, bzbufdesc);
108 			bzbufdesc = NULL;
109 			if (lseek(f->fd, 0, SEEK_SET) == -1)
110 				return (-1);
111 			nr = read(f->fd, buffer, MAXBUFSIZ);
112 			break;
113 		default:
114 			/* Make sure we exit with an error */
115 			nr = -1;
116 		}
117 	} else
118 #endif
119 		nr = read(f->fd, buffer, MAXBUFSIZ);
120 
121 	if (nr < 0)
122 		return (-1);
123 
124 	bufrem = nr;
125 	return (0);
126 }
127 
128 static inline int
grep_lnbufgrow(size_t newlen)129 grep_lnbufgrow(size_t newlen)
130 {
131 
132 	if (lnbuflen < newlen) {
133 		lnbuf = grep_realloc(lnbuf, newlen);
134 		lnbuflen = newlen;
135 	}
136 
137 	return (0);
138 }
139 
140 char *
grep_fgetln(struct file * f,size_t * lenp)141 grep_fgetln(struct file *f, size_t *lenp)
142 {
143 	unsigned char *p;
144 	char *ret;
145 	size_t len;
146 	size_t off;
147 	ptrdiff_t diff;
148 
149 	/* Fill the buffer, if necessary */
150 	if (bufrem == 0 && grep_refill(f) != 0)
151 		goto error;
152 
153 	if (bufrem == 0) {
154 		/* Return zero length to indicate EOF */
155 		*lenp = 0;
156 		return ((char *)bufpos);
157 	}
158 
159 	/* Look for a newline in the remaining part of the buffer */
160 	if ((p = memchr(bufpos, line_sep, bufrem)) != NULL) {
161 		++p; /* advance over newline */
162 		ret = (char *)bufpos;
163 		len = p - bufpos;
164 		bufrem -= len;
165 		bufpos = p;
166 		*lenp = len;
167 		return (ret);
168 	}
169 
170 	/* We have to copy the current buffered data to the line buffer */
171 	for (len = bufrem, off = 0; ; len += bufrem) {
172 		/* Make sure there is room for more data */
173 		if (grep_lnbufgrow(len + LNBUFBUMP))
174 			goto error;
175 		memcpy(lnbuf + off, bufpos, len - off);
176 		off = len;
177 		if (grep_refill(f) != 0)
178 			goto error;
179 		if (bufrem == 0)
180 			/* EOF: return partial line */
181 			break;
182 		if ((p = memchr(bufpos, line_sep, bufrem)) == NULL)
183 			continue;
184 		/* got it: finish up the line (like code above) */
185 		++p;
186 		diff = p - bufpos;
187 		len += diff;
188 		if (grep_lnbufgrow(len))
189 		    goto error;
190 		memcpy(lnbuf + off, bufpos, diff);
191 		bufrem -= diff;
192 		bufpos = p;
193 		break;
194 	}
195 	*lenp = len;
196 	return ((char *)lnbuf);
197 
198 error:
199 	*lenp = 0;
200 	return (NULL);
201 }
202 
203 static inline struct file *
grep_file_init(struct file * f)204 grep_file_init(struct file *f)
205 {
206 
207 #ifndef __ANDROID__
208 	if (filebehave == FILE_GZIP &&
209 	    (gzbufdesc = gzdopen(f->fd, "r")) == NULL)
210 		goto error;
211 
212 	if (filebehave == FILE_BZIP &&
213 	    (bzbufdesc = BZ2_bzdopen(f->fd, "r")) == NULL)
214 		goto error;
215 #endif
216 
217 	/* Fill read buffer, also catches errors early */
218 	if (grep_refill(f) != 0)
219 		goto error;
220 
221 	/* Check for binary stuff, if necessary */
222 	if (!nulldataflag && binbehave != BINFILE_TEXT &&
223 	    memchr(bufpos, '\0', bufrem) != NULL)
224 		f->binary = true;
225 
226 	return (f);
227 error:
228 	close(f->fd);
229 	free(f);
230 	return (NULL);
231 }
232 
233 /*
234  * Opens a file for processing.
235  */
236 struct file *
grep_open(const char * path)237 grep_open(const char *path)
238 {
239 	struct file *f;
240 
241 	f = grep_malloc(sizeof *f);
242 	memset(f, 0, sizeof *f);
243 	if (path == NULL) {
244 		/* Processing stdin implies --line-buffered. */
245 		lbflag = true;
246 		f->fd = STDIN_FILENO;
247 	} else if ((f->fd = open(path, O_RDONLY)) == -1) {
248 		free(f);
249 		return (NULL);
250 	}
251 
252 	return (grep_file_init(f));
253 }
254 
255 /*
256  * Closes a file.
257  */
258 void
grep_close(struct file * f)259 grep_close(struct file *f)
260 {
261 
262 	close(f->fd);
263 
264 	/* Reset read buffer and line buffer */
265 	bufpos = buffer;
266 	bufrem = 0;
267 
268 	free(lnbuf);
269 	lnbuf = NULL;
270 	lnbuflen = 0;
271 }
272