io

Functions
int	writen (int fd, unsigned char *ptr, int nbytes)
	write n bytes of data to a file descriptor
int	readn (int fd, unsigned char *ptr, int nbytes)
	read n bytes of data from a file descriptor

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Function Documentation

int readn	(	int	fd,
		unsigned char *	ptr,
		int	nbytes
	)

read n bytes of data from a file descriptor

On Linux, since read is not guaranteed to read all of the bytes available in one call, we continously read the specified number of bytes from the descriptor into the data buffer provided.

Parameters:

[in]	fd	the file descriptor to read from
[in,out]	ptr	the address of the data buffer to read into
[in]	nbytes	the number of bytes to read

Returns:

number of bytes successfully read

int writen	(	int	fd,
		unsigned char *	ptr,
		int	nbytes
	)

write n bytes of data to a file descriptor

On Linux, since write is not guaranteed to write all of the bytes provided, we keep track of the number of bytes written and retry sending the data as needed.

Parameters:

[in]	fd	the file descriptor to write to
[in]	ptr	the address of the data buffer to write
[in]	nbytes	the number of bytes to write

Returns:

number of bytes successfully written