diff options
Diffstat (limited to 'usr.bin/grep/file.c')
| -rw-r--r-- | usr.bin/grep/file.c | 248 |
1 files changed, 248 insertions, 0 deletions
diff --git a/usr.bin/grep/file.c b/usr.bin/grep/file.c new file mode 100644 index 000000000000..0b8240504ce6 --- /dev/null +++ b/usr.bin/grep/file.c @@ -0,0 +1,248 @@ +/* $NetBSD: file.c,v 1.5 2011/02/16 18:35:39 joerg Exp $ */ +/* $OpenBSD: file.c,v 1.11 2010/07/02 20:48:48 nicm Exp $ */ + +/*- + * SPDX-License-Identifier: BSD-2-Clause + * + * Copyright (c) 1999 James Howard and Dag-Erling 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/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 "grep.h" + +#define MAXBUFSIZ (32 * 1024) +#define LNBUFBUMP 80 + +static char *buffer; +static char *bufpos; +static size_t bufrem; +static size_t fsiz; + +static 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; + + nr = read(f->fd, buffer, MAXBUFSIZ); + if (nr < 0 && errno == EISDIR) + nr = 0; + 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, struct parsec *pc) +{ + char *p; + 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 */ + pc->ln.len= 0; + return (bufpos); + } + + /* Look for a newline in the remaining part of the buffer */ + if ((p = memchr(bufpos, fileeol, bufrem)) != NULL) { + ++p; /* advance over newline */ + len = p - bufpos; + if (grep_lnbufgrow(len + 1)) + goto error; + memcpy(lnbuf, bufpos, len); + bufrem -= len; + bufpos = p; + pc->ln.len = len; + lnbuf[len] = '\0'; + return (lnbuf); + } + + /* 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); + /* With FILE_MMAP, this is EOF; there's no more to refill */ + if (filebehave == FILE_MMAP) { + bufrem -= len; + break; + } + off = len; + /* Fetch more to try and find EOL/EOF */ + if (grep_refill(f) != 0) + goto error; + if (bufrem == 0) + /* EOF: return partial line */ + break; + if ((p = memchr(bufpos, fileeol, bufrem)) == NULL) + continue; + /* got it: finish up the line (like code above) */ + ++p; + diff = p - bufpos; + len += diff; + if (grep_lnbufgrow(len + 1)) + goto error; + memcpy(lnbuf + off, bufpos, diff); + bufrem -= diff; + bufpos = p; + break; + } + pc->ln.len = len; + lnbuf[len] = '\0'; + return (lnbuf); + +error: + pc->ln.len = 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 || !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); + + /* 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 && fileeol != '\0' && + 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; +} |