/* $NetBSD: file.c,v 1.5 2011/02/16 18:35:39 joerg Exp $ */
/* $FreeBSD$ */
/* $OpenBSD: file.c,v 1.11 2010/07/02 20:48:48 nicm Exp $ */
/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 1999 James Howard and Dag-Erling Coïdan 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/cdefs.h>
__FBSDID("$FreeBSD$");
#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)
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;
}
