full_io.h File Reference

Perform complete I/O operations, retrying through failures and signals. More...

#include <sys/types.h>
#include <stdint.h>
#include <stdio.h>

Go to the source code of this file.

Functions
ssize_t	full_read (int fd, void *buf, size_t count)
	Read the next bytes from a file descriptor. More...
ssize_t	full_write (int fd, const void *buf, size_t count)
	Write the next bytes to a file descriptor. More...
ssize_t	full_pread (int fd, void *buf, size_t count, off_t offset)
	Read arbitrary bytes from a file descriptor. More...
ssize_t	full_pwrite (int fd, const void *buf, size_t count, off_t offset)
	Write arbitrary bytes to a file descriptor. More...
ssize_t	full_pread64 (int fd, void *buf, size_t count, int64_t offset)
	Read arbitrary bytes from a file descriptor. More...
ssize_t	full_pwrite64 (int fd, const void *buf, size_t count, int64_t offset)
	Write arbitrary bytes to a file descriptor. More...
ssize_t	full_fread (FILE *file, void *buf, size_t count)
	Read the next bytes from a file stream. More...
ssize_t	full_fwrite (FILE *file, const void *buf, size_t count)
	Write the next bytes to a file stream. More...

Detailed Description

Perform complete I/O operations, retrying through failures and signals.

A subtle property of Unix is that the kernel may choose to leave an I/O operation incomplete, returning a smaller number of bytes than you requested, or simply giving up with the error EINTR, if it is simply more "convenient". The full_io routines look lik normal Unix read and write operations, but silently retry through temporary failures. Of course, these routines may still fail for more permanent reasons such as end of file or disk full.

Function Documentation

ssize_t full_read	(	int	fd,
		void *	buf,
		size_t	count
	)

Read the next bytes from a file descriptor.

Parameters

fd	File descriptor.
buf	Pointer to buffer.
count	The number of bytes to read.

Returns

The number of bytes actually read, or less than zero indicating error.

ssize_t full_write	(	int	fd,
		const void *	buf,
		size_t	count
	)

Write the next bytes to a file descriptor.

Parameters

fd	File descriptor.
buf	Pointer to buffer.
count	The number of bytes to write.

Returns

The number of bytes actually written, or less than zero indicating error.

ssize_t full_pread	(	int	fd,
		void *	buf,
		size_t	count,
		off_t	offset
	)

Read arbitrary bytes from a file descriptor.

Parameters

fd	File descriptor.
buf	Pointer to buffer.
count	The number of bytes to read.
offset	The offset in the file to begin from.

Returns

The number of bytes actually read, or less than zero indicating error.

ssize_t full_pwrite	(	int	fd,
		const void *	buf,
		size_t	count,
		off_t	offset
	)

Write arbitrary bytes to a file descriptor.

Parameters

fd	File descriptor.
buf	Pointer to buffer.
count	The number of bytes to write.
offset	The offset in the file to begin from.

Returns

The number of bytes actually written, or less than zero indicating error.

ssize_t full_pread64	(	int	fd,
		void *	buf,
		size_t	count,
		int64_t	offset
	)

Read arbitrary bytes from a file descriptor.

(64 bit)

Parameters

fd	File descriptor.
buf	Pointer to buffer.
count	The number of bytes to read.
offset	The offset in the file to begin from.

Returns

The number of bytes actually read, or less than zero indicating error.

ssize_t full_pwrite64	(	int	fd,
		const void *	buf,
		size_t	count,
		int64_t	offset
	)

Write arbitrary bytes to a file descriptor.

(64 bit)

Parameters

fd	File descriptor.
buf	Pointer to buffer.
count	The number of bytes to write.
offset	The offset in the file to begin from.

Returns

The number of bytes actually written, or less than zero indicating error.

ssize_t full_fread	(	FILE *	file,
		void *	buf,
		size_t	count
	)

Read the next bytes from a file stream.

Parameters

file	Standard file stream.
buf	Pointer to buffer.
count	The number of bytes to read.

Returns

The number of bytes actually read, or less than zero indicating error.

ssize_t full_fwrite	(	FILE *	file,
		const void *	buf,
		size_t	count
	)

Write the next bytes to a file stream.

Parameters

file	Standard file stream.
buf	Pointer to buffer.
count	The number of bytes to write.

Returns

The number of bytes actually written, or less than zero indicating error.