1/* $OpenBSD: file.c,v 1.11 2010/07/02 20:48:48 nicm Exp $ */
2
3/*-
4 * Copyright (c) 1999 James Howard and Dag-Erling Co�dan Sm�rgrav
5 * Copyright (C) 2008-2010 Gabor Kovesdan <gabor@FreeBSD.org>
6 * Copyright (C) 2010 Dimitry Andric <dimitry@andric.com>
7 * All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright

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24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 */
30
31#include <sys/cdefs.h>
32__FBSDID("$FreeBSD: head/usr.bin/grep/file.c 211463 2010-08-18 17:40:10Z gabor $");
33
34#include <sys/param.h>
35#include <sys/types.h>
36#include <sys/stat.h>
37
38#include <bzlib.h>
39#include <err.h>
40#include <errno.h>
41#include <fcntl.h>
42#include <stddef.h>
43#include <stdlib.h>
44#include <string.h>
45#include <unistd.h>
46#include <wchar.h>
47#include <wctype.h>
48#include <zlib.h>
49
50#include "grep.h"
51
52#define MAXBUFSIZ (32 * 1024)
53#define LNBUFBUMP 80
54
55static gzFile gzbufdesc;
56static BZFILE* bzbufdesc;
57
58static unsigned char buffer[MAXBUFSIZ];
59static unsigned char *bufpos;
60static size_t bufrem;
61
62static unsigned char *lnbuf;
63static size_t lnbuflen;
64
65static inline int
66grep_refill(struct file *f)
67{
68 ssize_t nr;
69 int bzerr;
70
71 bufpos = buffer;
72 bufrem = 0;
73
74 if (filebehave == FILE_GZIP)
75 nr = gzread(gzbufdesc, buffer, MAXBUFSIZ);
76 else if (filebehave == FILE_BZIP && bzbufdesc != NULL) {
77 nr = BZ2_bzRead(&bzerr, bzbufdesc, buffer, MAXBUFSIZ);
78 switch (bzerr) {
79 case BZ_OK:
80 case BZ_STREAM_END:
81 /* No problem, nr will be okay */
82 break;
83 case BZ_DATA_ERROR_MAGIC:
84 /*
85 * As opposed to gzread(), which simply returns the
86 * plain file data, if it is not in the correct
87 * compressed format, BZ2_bzRead() instead aborts.
88 *
89 * So, just restart at the beginning of the file again,
90 * and use plain reads from now on.
91 */
92 BZ2_bzReadClose(&bzerr, bzbufdesc);
93 bzbufdesc = NULL;
94 if (lseek(f->fd, 0, SEEK_SET) == -1)
95 return (-1);
96 nr = read(f->fd, buffer, MAXBUFSIZ);
97 break;
98 default:
99 /* Make sure we exit with an error */
100 nr = -1;
101 }
102 } else
103 nr = read(f->fd, buffer, MAXBUFSIZ);
104
105 if (nr < 0)
106 return (-1);
107
108 bufrem = nr;
109 return (0);
110}
111
112static inline int
113grep_lnbufgrow(size_t newlen)
114{
115
116 if (lnbuflen < newlen) {
117 lnbuf = grep_realloc(lnbuf, newlen);
118 lnbuflen = newlen;
119 }
120
121 return (0);
122}
123
124char *
125grep_fgetln(struct file *f, size_t *lenp)
126{
127 unsigned char *p;
128 char *ret;
129 size_t len;
130 size_t off;
131 ptrdiff_t diff;
132
133 /* Fill the buffer, if necessary */
134 if (bufrem == 0 && grep_refill(f) != 0)
135 goto error;
136
137 if (bufrem == 0) {
138 /* Return zero length to indicate EOF */
139 *lenp = 0;
140 return (bufpos);
141 }
142
143 /* Look for a newline in the remaining part of the buffer */
144 if ((p = memchr(bufpos, '\n', bufrem)) != NULL) {
145 ++p; /* advance over newline */
146 ret = bufpos;
147 len = p - bufpos;
148 bufrem -= len;
149 bufpos = p;
150 *lenp = len;
151 return (ret);
152 }
153
154 /* We have to copy the current buffered data to the line buffer */
155 for (len = bufrem, off = 0; ; len += bufrem) {
156 /* Make sure there is room for more data */
157 if (grep_lnbufgrow(len + LNBUFBUMP))
158 goto error;
159 memcpy(lnbuf + off, bufpos, len - off);
160 off = len;
161 if (grep_refill(f) != 0)
162 goto error;
163 if (bufrem == 0)
164 /* EOF: return partial line */
165 break;
166 if ((p = memchr(bufpos, '\n', bufrem)) == NULL)
167 continue;
168 /* got it: finish up the line (like code above) */
169 ++p;
170 diff = p - bufpos;
171 len += diff;
172 if (grep_lnbufgrow(len))
173 goto error;
174 memcpy(lnbuf + off, bufpos, diff);
175 bufrem -= diff;
176 bufpos = p;
177 break;
178 }
179 *lenp = len;
180 return (lnbuf);
181
182error:
183 *lenp = 0;
184 return (NULL);
185}
186
187static inline struct file *
188grep_file_init(struct file *f)
189{
190
191 if (filebehave == FILE_GZIP &&
192 (gzbufdesc = gzdopen(f->fd, "r")) == NULL)
193 goto error;
194
195 if (filebehave == FILE_BZIP &&
196 (bzbufdesc = BZ2_bzdopen(f->fd, "r")) == NULL)
197 goto error;
198
199 /* Fill read buffer, also catches errors early */
200 if (grep_refill(f) != 0)
201 goto error;
202
203 /* Check for binary stuff, if necessary */
204 if (binbehave != BINFILE_TEXT && memchr(bufpos, '\0', bufrem) != NULL)
205 f->binary = true;
206
207 return (f);
208error:
209 close(f->fd);
210 free(f);
211 return (NULL);
212}
213
214/*
215 * Opens a file for processing.
216 */
217struct file *
218grep_open(const char *path)
219{
220 struct file *f;
221
222 f = grep_malloc(sizeof *f);
223 memset(f, 0, sizeof *f);
224 if (path == NULL) {
225 /* Processing stdin implies --line-buffered. */
226 lbflag = true;
227 f->fd = STDIN_FILENO;
228 } else if ((f->fd = open(path, O_RDONLY)) == -1) {
229 free(f);
230 return (NULL);
231 }
232
233 return (grep_file_init(f));
234}
235
236/*
237 * Closes a file.
238 */
239void
240grep_close(struct file *f)
241{
242
243 close(f->fd);
244
245 /* Reset read buffer and line buffer */
246 bufpos = buffer;
247 bufrem = 0;
248
249 free(lnbuf);
250 lnbuf = NULL;
251 lnbuflen = 0;
252}