1 /* $NetBSD: file.c,v 1.5 2011/02/16 18:35:39 joerg Exp $ */ 2 /* $FreeBSD$ */ 3 /* $OpenBSD: file.c,v 1.11 2010/07/02 20:48:48 nicm Exp $ */ 4 5 /*- 6 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 7 * 8 * Copyright (c) 1999 James Howard and Dag-Erling Coïdan Smørgrav 9 * Copyright (C) 2008-2010 Gabor Kovesdan <gabor@FreeBSD.org> 10 * Copyright (C) 2010 Dimitry Andric <dimitry@andric.com> 11 * All rights reserved. 12 * 13 * Redistribution and use in source and binary forms, with or without 14 * modification, are permitted provided that the following conditions 15 * are met: 16 * 1. Redistributions of source code must retain the above copyright 17 * notice, this list of conditions and the following disclaimer. 18 * 2. Redistributions in binary form must reproduce the above copyright 19 * notice, this list of conditions and the following disclaimer in the 20 * documentation and/or other materials provided with the distribution. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 35 #include <sys/cdefs.h> 36 __FBSDID("$FreeBSD$"); 37 38 #include <sys/param.h> 39 #include <sys/mman.h> 40 #include <sys/stat.h> 41 #include <sys/types.h> 42 43 #include <err.h> 44 #include <errno.h> 45 #include <fcntl.h> 46 #include <stddef.h> 47 #include <stdlib.h> 48 #include <string.h> 49 #include <unistd.h> 50 #include <wchar.h> 51 #include <wctype.h> 52 53 #include "grep.h" 54 55 #define MAXBUFSIZ (32 * 1024) 56 #define LNBUFBUMP 80 57 58 static char *buffer; 59 static char *bufpos; 60 static size_t bufrem; 61 static size_t fsiz; 62 63 static char *lnbuf; 64 static size_t lnbuflen; 65 66 static inline int 67 grep_refill(struct file *f) 68 { 69 ssize_t nr; 70 71 if (filebehave == FILE_MMAP) 72 return (0); 73 74 bufpos = buffer; 75 bufrem = 0; 76 77 nr = read(f->fd, buffer, MAXBUFSIZ); 78 if (nr < 0) 79 return (-1); 80 81 bufrem = nr; 82 return (0); 83 } 84 85 static inline int 86 grep_lnbufgrow(size_t newlen) 87 { 88 89 if (lnbuflen < newlen) { 90 lnbuf = grep_realloc(lnbuf, newlen); 91 lnbuflen = newlen; 92 } 93 94 return (0); 95 } 96 97 char * 98 grep_fgetln(struct file *f, struct parsec *pc) 99 { 100 char *p; 101 size_t len; 102 size_t off; 103 ptrdiff_t diff; 104 105 /* Fill the buffer, if necessary */ 106 if (bufrem == 0 && grep_refill(f) != 0) 107 goto error; 108 109 if (bufrem == 0) { 110 /* Return zero length to indicate EOF */ 111 pc->ln.len= 0; 112 return (bufpos); 113 } 114 115 /* Look for a newline in the remaining part of the buffer */ 116 if ((p = memchr(bufpos, fileeol, bufrem)) != NULL) { 117 ++p; /* advance over newline */ 118 len = p - bufpos; 119 if (grep_lnbufgrow(len + 1)) 120 goto error; 121 memcpy(lnbuf, bufpos, len); 122 bufrem -= len; 123 bufpos = p; 124 pc->ln.len = len; 125 lnbuf[len] = '\0'; 126 return (lnbuf); 127 } 128 129 /* We have to copy the current buffered data to the line buffer */ 130 for (len = bufrem, off = 0; ; len += bufrem) { 131 /* Make sure there is room for more data */ 132 if (grep_lnbufgrow(len + LNBUFBUMP)) 133 goto error; 134 memcpy(lnbuf + off, bufpos, len - off); 135 /* With FILE_MMAP, this is EOF; there's no more to refill */ 136 if (filebehave == FILE_MMAP) { 137 bufrem -= len; 138 break; 139 } 140 off = len; 141 /* Fetch more to try and find EOL/EOF */ 142 if (grep_refill(f) != 0) 143 goto error; 144 if (bufrem == 0) 145 /* EOF: return partial line */ 146 break; 147 if ((p = memchr(bufpos, fileeol, bufrem)) == NULL) 148 continue; 149 /* got it: finish up the line (like code above) */ 150 ++p; 151 diff = p - bufpos; 152 len += diff; 153 if (grep_lnbufgrow(len + 1)) 154 goto error; 155 memcpy(lnbuf + off, bufpos, diff); 156 bufrem -= diff; 157 bufpos = p; 158 break; 159 } 160 pc->ln.len = len; 161 lnbuf[len] = '\0'; 162 return (lnbuf); 163 164 error: 165 pc->ln.len = 0; 166 return (NULL); 167 } 168 169 /* 170 * Opens a file for processing. 171 */ 172 struct file * 173 grep_open(const char *path) 174 { 175 struct file *f; 176 177 f = grep_malloc(sizeof *f); 178 memset(f, 0, sizeof *f); 179 if (path == NULL) { 180 /* Processing stdin implies --line-buffered. */ 181 lbflag = true; 182 f->fd = STDIN_FILENO; 183 } else if ((f->fd = open(path, O_RDONLY)) == -1) 184 goto error1; 185 186 if (filebehave == FILE_MMAP) { 187 struct stat st; 188 189 if (fstat(f->fd, &st) == -1 || !S_ISREG(st.st_mode)) 190 filebehave = FILE_STDIO; 191 else { 192 int flags = MAP_PRIVATE | MAP_NOCORE | MAP_NOSYNC; 193 #ifdef MAP_PREFAULT_READ 194 flags |= MAP_PREFAULT_READ; 195 #endif 196 fsiz = st.st_size; 197 buffer = mmap(NULL, fsiz, PROT_READ, flags, 198 f->fd, (off_t)0); 199 if (buffer == MAP_FAILED) 200 filebehave = FILE_STDIO; 201 else { 202 bufrem = st.st_size; 203 bufpos = buffer; 204 madvise(buffer, st.st_size, MADV_SEQUENTIAL); 205 } 206 } 207 } 208 209 if ((buffer == NULL) || (buffer == MAP_FAILED)) 210 buffer = grep_malloc(MAXBUFSIZ); 211 212 /* Fill read buffer, also catches errors early */ 213 if (bufrem == 0 && grep_refill(f) != 0) 214 goto error2; 215 216 /* Check for binary stuff, if necessary */ 217 if (binbehave != BINFILE_TEXT && fileeol != '\0' && 218 memchr(bufpos, '\0', bufrem) != NULL) 219 f->binary = true; 220 221 return (f); 222 223 error2: 224 close(f->fd); 225 error1: 226 free(f); 227 return (NULL); 228 } 229 230 /* 231 * Closes a file. 232 */ 233 void 234 grep_close(struct file *f) 235 { 236 237 close(f->fd); 238 239 /* Reset read buffer and line buffer */ 240 if (filebehave == FILE_MMAP) { 241 munmap(buffer, fsiz); 242 buffer = NULL; 243 } 244 bufpos = buffer; 245 bufrem = 0; 246 247 free(lnbuf); 248 lnbuf = NULL; 249 lnbuflen = 0; 250 } 251