fd.h File Reference

File descriptor wrappers. More...

#include <wfio/type.h>
#include <stdarg.h>
#include <wfio/device.h>

Go to the source code of this file.

Classes
class	wfio::FDDevice
	A Device wrapping a file descriptor. More...

Namespaces
	wfio
	The root namespace for WFIO.

Functions
WFIO_C_BEGIN WFIO_DLL struct wfio_device_t *	wfio_device_from_fd (wfio_fd_t handle, int *error)
	Wrap the device with the given file descriptor handle. More...
WFIO_DLL wfio_fd_t	wfio_fd_open (const char *path, const char *mode, int *error)
	Open a new file descriptor for the given path and in the specified STDIO mode mode. More...
WFIO_DLL wfio_fd_t	wfio_fd_openEx (const char *path, wfio_openmode_t mode, int *error)
	Open a new file descriptor for the given path and in the specified openmode mode. More...
WFIO_DLL void	wfio_fd_close (wfio_fd_t fd)
	Close a presently open file descriptor. More...
WFIO_DLL_FASTCALL size_t	wfio_fd_read (wfio_fd_t fd, void *buf, size_t len, int *error)
	Read from a file descriptor. More...
WFIO_DLL_FASTCALL size_t	wfio_fd_write (wfio_fd_t fd, const void *buf, size_t len, int *error)
	Write to a file descriptor. More...
WFIO_DLL_FASTCALL int	wfio_fd_seek (wfio_fd_t fd, wfio_off_t offset, wfio_whence_t whence, int *error)
	Seek to a position in the file descriptor's stream. More...
WFIO_DLL_FASTCALL wfio_off_t	wfio_fd_tell (wfio_fd_t fd, int *error)
	Determine the current stream position of this file descriptor. More...
WFIO_DLL_FASTCALL wfio_fd_t	wfio_fd_dup (wfio_fd_t fd, int *error)
	Duplicate a file descriptor. More...
WFIO_DLL_FASTCALL int	wfio_fd_vioctl (wfio_fd_t fd, int cmd, int *error, va_list va)
	Perform device-dependent I/O control on the supplied file descriptor. More...
WFIO_INLINE int	wfio_fd_ioctl (wfio_fd_t fd, int cmd, int *error,...)
	Perform device-dependent I/O control on the supplied file descriptor. More...
WFIO_DLL int	wfio_fd_setflags (wfio_fd_t fd, int flags, int *error)
	Update the device flags of the file descriptor fd. More...
WFIO_DLL int	wfio_fd_getflags (wfio_fd_t fd, int *error)
	Obtain the device flags corresponding to the file descriptor fd. More...
WFIO_DLL int	wfio_fd_truncate (wfio_fd_t fd, size_t sz, int *error)
	Resize the resource represented by the file descriptor fd to be no greater than sz. More...

Detailed Description

File descriptor wrappers.

Author

Phillip Kilgore

Since

0.0.1

Function Documentation

wfio_device_from_fd()

WFIO_C_BEGIN WFIO_DLL struct wfio_device_t* wfio_device_from_fd	(	wfio_fd_t	handle,
		int *	error
	)

Wrap the device with the given file descriptor handle.

This function creates a new device which wraps around a file descriptor. It shall behave as if the wfio_fd_* functions corresponding to each operation was used.

Parameters

handle	The file handle to wrap.
error	An optional error indicator.

Returns

An open wfar_device_t on success; otherwise, NULL.

wfio_fd_close()

WFIO_DLL void wfio_fd_close

(

wfio_fd_t

fd

)

Close a presently open file descriptor.

Parameters

fd	The file descriptor to close.

wfio_fd_dup()

WFIO_DLL_FASTCALL wfio_fd_t wfio_fd_dup	(	wfio_fd_t	fd,
		int *	error
	)

Duplicate a file descriptor.

Parameters

fd	The file descriptor to duplicate.

wfio_fd_getflags()

WFIO_DLL int wfio_fd_getflags	(	wfio_fd_t	fd,
		int *	error
	)

Obtain the device flags corresponding to the file descriptor fd.

Parameters

fd	The file descriptor to manipulate.
flags	The device flags to set.
error	An optional error indicator.

Returns

Nonzero on success; otherwise, failure.

wfio_fd_ioctl()

WFIO_INLINE int wfio_fd_ioctl	(	wfio_fd_t	fd,
		int	cmd,
		int *	error,
			...
	)

Perform device-dependent I/O control on the supplied file descriptor.

Calling this function occurs in a purely implementation-defined manner. On UNIX systems, the behavior shall be the same as if ioctl() was called.

Parameters

fd	The file descriptor to ioctl.
cmd	The command to send to the file descriptor.
error	An optional error indicator.
...	Additional arguments to the ioctl.

Returns

A value peculiar to cmd.

Note

It is not sufficient to look at the return value from this function to determine failure because the return value is dependent on the ioctl command. Instead, check he value of error; if the value is WFIO_E_SUCCESS, then no error has occurred.

wfio_fd_open()

WFIO_DLL wfio_fd_t wfio_fd_open	(	const char *	path,
		const char *	mode,
		int *	error
	)

Open a new file descriptor for the given path and in the specified STDIO mode mode.

Parameters

path	The pathname to open.

wfio_fd_openEx()

WFIO_DLL wfio_fd_t wfio_fd_openEx	(	const char *	path,
		wfio_openmode_t	mode,
		int *	error
	)

Open a new file descriptor for the given path and in the specified openmode mode.

Parameters

path	The pathname to open.

wfio_fd_read()

WFIO_DLL_FASTCALL size_t wfio_fd_read	(	wfio_fd_t	fd,
		void *	buf,
		size_t	len,
		int *	error
	)

Read from a file descriptor.

This function reads from a file descriptor by wrapping the host's method of doing so.

Parameters

fd	The file descriptor to read.
buf	The buffer to read into.
len	The maximum number of bytes to read.
error	An optional error indicator.
The	number of bytes read on success; otherwise, WFIO_NPOS.

wfio_fd_seek()

WFIO_DLL_FASTCALL int wfio_fd_seek	(	wfio_fd_t	fd,
		wfio_off_t	offset,
		wfio_whence_t	whence,
		int *	error
	)

Seek to a position in the file descriptor's stream.

Parameters

fd	The file descriptor to seek.
offset	The offset relative to whence to seek to.
whence	The origin from whence to seek.
error	An optional error indicator.

Returns

Nonzero on success; otherwise, zero.

wfio_fd_setflags()

WFIO_DLL int wfio_fd_setflags	(	wfio_fd_t	fd,
		int	flags,
		int *	error
	)

Update the device flags of the file descriptor fd.

Parameters

fd	The file descriptor to manipulate.
flags	The device flags to set.
error	An optional error indicator.

Returns

Nonzero on success; otherwise, failure.

wfio_fd_tell()

WFIO_DLL_FASTCALL wfio_off_t wfio_fd_tell	(	wfio_fd_t	fd,
		int *	error
	)

Determine the current stream position of this file descriptor.

Parameters

fd	The file descriptor to seek.
error	An optional error indicator.

Returns

The current stream position on success; otherwise, WFIO_NPOS.

wfio_fd_truncate()

WFIO_DLL int wfio_fd_truncate	(	wfio_fd_t	fd,
		size_t	sz,
		int *	error
	)

Resize the resource represented by the file descriptor fd to be no greater than sz.

Parameters

fd	The file descriptor to manipulate.
sz	The desired size of the file descriptor.
error	An optional error indicator.

Returns

Nonzero on success; otherwise, failure.

wfio_fd_vioctl()

WFIO_DLL_FASTCALL int wfio_fd_vioctl	(	wfio_fd_t	fd,
		int	cmd,
		int *	error,
		va_list	va
	)

Perform device-dependent I/O control on the supplied file descriptor.

This function is like wfio_fd_ioctl(), except that it operates on a va_list instead.

Parameters

fd	The file descriptor to ioctl.
cmd	The command to send to the file descriptor.
error	An optional error indicator.
va	Additional arguments to the ioctl.

Returns

A value peculiar to cmd.

Note

It is not sufficient to look at the return value from this function to determine failure because the return value is dependent on the ioctl command. Instead, check he value of error; if the value is WFIO_E_SUCCESS, then no error has occurred.

wfio_fd_write()

WFIO_DLL_FASTCALL size_t wfio_fd_write	(	wfio_fd_t	fd,
		const void *	buf,
		size_t	len,
		int *	error
	)

Write to a file descriptor.

This function write from a file descriptor by wrapping the host's method of doing so.

Parameters

fd	The file descriptor to write.
buf	The buffer to write from.
len	The maximum number of bytes to write.
error	An optional error indicator.
The	number of bytes read on success; otherwise, WFIO_NPOS.