op_deviceio.h File Reference

#include "op_types.h"
#include <unistd.h>

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Functions
fd_t	op_open_device (char const *name)
ssize_t	op_read_device (fd_t devfd, void *buf, size_t size)

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Detailed Description

Reading from a special device

Remarks:

Copyright 2002 OProfile authors

Read the file COPYING

Author:

John Levon

Philippe Elie

Definition in file op_deviceio.h.

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Function Documentation

fd_t op_open_device

(

char const *

name

)

op_open_device - open a special char device for reading

Parameters:

name

file name of device file

Open the special file name. Returns the file descriptor for the file or -1 on error.

Definition at line 22 of file op_deviceio.c.

Referenced by op_open_files(), and opd_open_files().

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ssize_t op_read_device	(	fd_t	devfd,
		void *	buf,
		size_t	size
	)

op_read_device - read from a special char device

Parameters:

	devfd	file descriptor of device
	buf	buffer
	size	size of buffer

Read size bytes from a device into buffer buf. A seek to the start of the device file is done first then a read is requested in one go of size bytes.

It is the caller's responsibility to do further op_read_device() calls if the number of bytes read is not what is requested (where this is applicable).

The number of bytes read is returned, or a negative number on failure (in which case errno will be set). If the call is interrupted, then errno will be EINTR, and the client should arrange for re-starting the read if necessary.

Definition at line 28 of file op_deviceio.c.

Referenced by opd_do_read(), and opd_shutdown().

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