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