freebsd-dev/usr.bin/tar/line_reader.c
Tim Kientzle 3b7dbff339 Merge a bunch of refactoring from Joerg Sonnenberger to
isolate common code used by tar and cpio (and useful to other
libarchive clients).  The functions here are prefixed with
"lafe" (libarchive front-end) to indicate their use.
2010-02-07 02:00:26 +00:00

172 lines
5.1 KiB
C

/*-
* Copyright (c) 2008 Tim Kientzle
* 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
* in this position and unchanged.
* 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(S) ``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(S) 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 "bsdtar_platform.h"
__FBSDID("$FreeBSD$");
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "err.h"
#include "line_reader.h"
#if defined(_WIN32) && !defined(__CYGWIN__) && !defined(__BORLANDC__)
#define strdup _strdup
#endif
/*
* Read lines from file and do something with each one. If option_null
* is set, lines are terminated with zero bytes; otherwise, they're
* terminated with newlines.
*
* This uses a self-sizing buffer to handle arbitrarily-long lines.
*/
struct lafe_line_reader {
FILE *f;
char *buff, *buff_end, *line_start, *line_end, *p;
char *pathname;
size_t buff_length;
int nullSeparator; /* Lines separated by null, not CR/CRLF/etc. */
int ret;
};
struct lafe_line_reader *
lafe_line_reader(const char *pathname, int nullSeparator)
{
struct lafe_line_reader *lr;
lr = calloc(1, sizeof(*lr));
if (lr == NULL)
bsdtar_errc(1, ENOMEM, "Can't open %s", pathname);
lr->nullSeparator = nullSeparator;
lr->pathname = strdup(pathname);
if (strcmp(pathname, "-") == 0)
lr->f = stdin;
else
lr->f = fopen(pathname, "r");
if (lr->f == NULL)
bsdtar_errc(1, errno, "Couldn't open %s", pathname);
lr->buff_length = 8192;
lr->buff = malloc(lr->buff_length);
if (lr->buff == NULL)
bsdtar_errc(1, ENOMEM, "Can't read %s", pathname);
lr->line_start = lr->line_end = lr->buff_end = lr->buff;
return (lr);
}
const char *
lafe_line_reader_next(struct lafe_line_reader *lr)
{
size_t bytes_wanted, bytes_read, new_buff_size;
char *line_start, *p;
for (;;) {
/* If there's a line in the buffer, return it immediately. */
while (lr->line_end < lr->buff_end) {
if (lr->nullSeparator) {
if (*lr->line_end == '\0') {
line_start = lr->line_start;
lr->line_start = lr->line_end + 1;
lr->line_end = lr->line_start;
return (line_start);
}
} else if (*lr->line_end == '\x0a' || *lr->line_end == '\x0d') {
*lr->line_end = '\0';
line_start = lr->line_start;
lr->line_start = lr->line_end + 1;
lr->line_end = lr->line_start;
if (line_start[0] != '\0')
return (line_start);
}
lr->line_end++;
}
/* If we're at end-of-file, process the final data. */
if (lr->f == NULL) {
/* If there's more text, return one last line. */
if (lr->line_end > lr->line_start) {
*lr->line_end = '\0';
line_start = lr->line_start;
lr->line_start = lr->line_end + 1;
lr->line_end = lr->line_start;
return (line_start);
}
/* Otherwise, we're done. */
return (NULL);
}
/* Buffer only has part of a line. */
if (lr->line_start > lr->buff) {
/* Move a leftover fractional line to the beginning. */
memmove(lr->buff, lr->line_start,
lr->buff_end - lr->line_start);
lr->buff_end -= lr->line_start - lr->buff;
lr->line_end -= lr->line_start - lr->buff;
lr->line_start = lr->buff;
} else {
/* Line is too big; enlarge the buffer. */
new_buff_size = lr->buff_length * 2;
if (new_buff_size <= lr->buff_length)
bsdtar_errc(1, ENOMEM,
"Line too long in %s", lr->pathname);
lr->buff_length = new_buff_size;
p = realloc(lr->buff, new_buff_size);
if (p == NULL)
bsdtar_errc(1, ENOMEM,
"Line too long in %s", lr->pathname);
lr->buff_end = p + (lr->buff_end - lr->buff);
lr->line_end = p + (lr->line_end - lr->buff);
lr->line_start = lr->buff = p;
}
/* Get some more data into the buffer. */
bytes_wanted = lr->buff + lr->buff_length - lr->buff_end;
bytes_read = fread(lr->buff_end, 1, bytes_wanted, lr->f);
lr->buff_end += bytes_read;
if (ferror(lr->f))
bsdtar_errc(1, errno, "Can't read %s", lr->pathname);
if (feof(lr->f)) {
if (lr->f != stdin)
fclose(lr->f);
lr->f = NULL;
}
}
}
void
lafe_line_reader_free(struct lafe_line_reader *lr)
{
free(lr->buff);
free(lr->pathname);
free(lr);
}