locking.c File Reference

Netatalk utility functions: locking. More...

#include <fcntl.h>
#include <unistd.h>
#include <atalk/util.h>

Functions
int	lock_reg (int fd, int cmd, int type, off_t offset, int whence, off_t len)
	lock a file with fctnl

Detailed Description

Netatalk utility functions: locking.

Function Documentation

lock_reg()

int lock_reg	(	int	fd,
		int	cmd,
		int	type,
		off_t	offset,
		int	whence,
		off_t	len )

lock a file with fctnl

This function is called via the macros: read_lock, write_lock, un_lock

Parameters

[in]	fd	File descriptor
[in]	cmd	cmd to fcntl, only F_SETLK is usable here
[in]	type	F_RDLCK, F_WRLCK, F_UNLCK
[in]	offset	byte offset relative to l_whence
[in]	whence	SEEK_SET, SEEK_CUR, SEEK_END
[in]	len	no. of bytes (0 means to EOF)

Returns

0 on success, -1 on failure with fcntl return value and errno

See also

read_lock, write_lock, unlock