/build/buildd/xz-utils-4.999.9beta+20091116/src/xz/file_io.c File Reference

File opening, unlinking, and closing. More...

#include "private.h"
#include <fcntl.h>
#include "tuklib_open_stdxxx.h"

Defines
#define	O_BINARY   0
#define	O_NOCTTY   0
Functions
void	io_init (void)
	Initialize the I/O module.
static void	io_unlink (const char *name, const struct stat *known_st)
	Unlink a file.
static void	io_copy_attrs (const file_pair *pair)
	Copies owner/group and permissions.
static bool	io_open_src (file_pair *pair)
	Opens the source file. Returns false on success, true on error.
static void	io_close_src (file_pair *pair, bool success)
	Closes source file of the file_pair structure.
static bool	io_open_dest (file_pair *pair)
static int	io_close_dest (file_pair *pair, bool success)
	Closes destination file of the file_pair structure.
file_pair *	io_open (const char *src_name)
	Opens a file pair.
void	io_close (file_pair *pair, bool success)
	Closes the file descriptors and frees possible allocated memory.
size_t	io_read (file_pair *pair, uint8_t *buf, size_t size)
	Reads from the source file to a buffer.
bool	io_write (const file_pair *pair, const uint8_t *buf, size_t size)
	Writes a buffer to the destination file.
Variables
static bool	warn_fchown

---

Detailed Description

File opening, unlinking, and closing.

---

Function Documentation

void io_init

(

void

)

Initialize the I/O module.

static void io_unlink	(	const char *	name,
		const struct stat *	known_st
	)			[static]

Unlink a file.

This tries to verify that the file being unlinked really is the file that we want to unlink by verifying device and inode numbers. There's still a small unavoidable race, but this is much better than nothing (the file could have been moved/replaced even hours earlier).

References message_error().

Referenced by io_close_dest(), and io_close_src().

static void io_copy_attrs

(

const file_pair *

pair

)

[static]

Copies owner/group and permissions.

Todo:

ACL and EA support

References file_pair::dest_fd, file_pair::dest_name, message_warning(), and file_pair::src_st.

Referenced by io_close().

static bool io_open_src

(

file_pair *

pair

)

[static]

Opens the source file. Returns false on success, true on error.

References message_error(), message_warning(), signals_block(), signals_unblock(), file_pair::src_fd, file_pair::src_name, file_pair::src_st, and user_abort.

Referenced by io_open().

static void io_close_src	(	file_pair *	pair,
		bool	success
	)			[static]

Closes source file of the file_pair structure.

Parameters:

	pair	File whose src_fd should be closed
	success	If true, the file will be removed from the disk if closing succeeds and --keep hasn't been used.

References io_unlink(), file_pair::src_fd, file_pair::src_name, and file_pair::src_st.

Referenced by io_close(), and io_open().

static int io_close_dest	(	file_pair *	pair,
		bool	success
	)			[static]

Closes destination file of the file_pair structure.

Parameters:

	pair	File whose dest_fd should be closed
	success	If false, the file will be removed from the disk.

Returns:

Zero if closing succeeds. On error, -1 is returned and error message printed.

References file_pair::dest_fd, file_pair::dest_name, file_pair::dest_st, io_unlink(), and message_error().

Referenced by io_close().

file_pair* io_open

(

const char *

src_name

)

Opens a file pair.

References io_close_src(), io_open_src(), is_empty_filename(), signals_block(), signals_unblock(), file_pair::src_name, and user_abort.

Referenced by coder_run().

void io_close	(	file_pair *	pair,
		bool	success
	)

Closes the file descriptors and frees possible allocated memory.

The success argument determines if source or destination file gets unlinked:

• false: The destination file is unlinked.
• true: The source file is unlinked unless writing to stdout or --keep was used.

References file_pair::dest_fd, io_close_dest(), io_close_src(), io_copy_attrs(), signals_block(), and signals_unblock().

Referenced by coder_run().

size_t io_read	(	file_pair *	pair,
		uint8_t *	buf,
		size_t	size
	)

Reads from the source file to a buffer.

Parameters:

	pair	File pair having the source file open for reading
	buf	Destination buffer to hold the read data
	size	Size of the buffer; assumed be smaller than SSIZE_MAX

Returns:

On success, number of bytes read is returned. On end of file zero is returned and pair->src_eof set to true. On error, SIZE_MAX is returned and error message printed.

References message_error(), file_pair::src_eof, file_pair::src_fd, file_pair::src_name, and user_abort.

Referenced by coder_normal(), coder_passthru(), and coder_run().

bool io_write	(	const file_pair *	pair,
		const uint8_t *	buf,
		size_t	size
	)

Writes a buffer to the destination file.

Parameters:

	pair	File pair having the destination file open for writing
	buf	Buffer containing the data to be written
	size	Size of the buffer; assumed be smaller than SSIZE_MAX

Returns:

On success, zero is returned. On error, -1 is returned and error message printed.

References file_pair::dest_fd, file_pair::dest_name, message_error(), and user_abort.

Referenced by coder_normal(), and coder_passthru().