UNIX-alike API

This is the UNIX-alike API, built on top of the basic API. More...

Functions
ssize_t	jread (jfs_t *fs, void *buf, size_t count)
	Read from the file.
ssize_t	jpread (jfs_t *fs, void *buf, size_t count, off_t offset)
	Read from the file at the given offset.
ssize_t	jreadv (jfs_t *fs, const struct iovec *vector, int count)
	Read from the file into multiple buffers.
ssize_t	jwrite (jfs_t *fs, const void *buf, size_t count)
	Write to the file.
ssize_t	jpwrite (jfs_t *fs, const void *buf, size_t count, off_t offset)
	Write to the file at the given offset.
ssize_t	jwritev (jfs_t *fs, const struct iovec *vector, int count)
	Write to the file from multiple buffers.
int	jtruncate (jfs_t *fs, off_t length)
	Truncates the file to the given length.
off_t	jlseek (jfs_t *fs, off_t offset, int whence)
	Reposition read/write file offset.

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Detailed Description

This is the UNIX-alike API, built on top of the basic API.

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Function Documentation

ssize_t jread	(	jfs_t *	fs,
		void *	buf,
		size_t	count
	)

Read from the file.

Works just like UNIX read(2).

Parameters:

	fs	file to read from
	buf	buffer used to store the data
	count	maximum number of bytes to read

Returns:

number of bytes read on success, or -1 on error

See also:

read(2)

ssize_t jpread	(	jfs_t *	fs,
		void *	buf,
		size_t	count,
		off_t	offset
	)

Read from the file at the given offset.

Works just like UNIX pread(2).

Parameters:

	fs	file to read from
	buf	buffer used to store the data
	count	maximum number of bytes to read
	offset	offset to read at

Returns:

number of bytes read on success, or -1 on error

See also:

pread(2)

ssize_t jreadv	(	jfs_t *	fs,
		const struct iovec *	vector,
		int	count
	)

Read from the file into multiple buffers.

Works just like UNIX readv(2).

Parameters:

	fs	file to read from
	vector	buffers used to store the data
	count	maximum number of bytes to read

Returns:

number of bytes read on success, or -1 on error

See also:

readv(2)

ssize_t jwrite	(	jfs_t *	fs,
		const void *	buf,
		size_t	count
	)

Write to the file.

Works just like UNIX write(2).

Parameters:

	fs	file to write to
	buf	buffer used to read the data from
	count	maximum number of bytes to write

Returns:

number of bytes written on success, or -1 on error

See also:

write(2)

ssize_t jpwrite	(	jfs_t *	fs,
		const void *	buf,
		size_t	count,
		off_t	offset
	)

Write to the file at the given offset.

Works just like UNIX pwrite(2).

Parameters:

	fs	file to write to
	buf	buffer used to read the data from
	count	maximum number of bytes to write
	offset	offset to write at

Returns:

number of bytes written on success, or -1 on error

See also:

pwrite(2)

ssize_t jwritev	(	jfs_t *	fs,
		const struct iovec *	vector,
		int	count
	)

Write to the file from multiple buffers.

Works just like UNIX writev(2).

Parameters:

	fs	file to write to
	vector	buffers used to read the data from
	count	maximum number of bytes to write

Returns:

number of bytes written on success, or -1 on error

See also:

writev(2)

int jtruncate	(	jfs_t *	fs,
		off_t	length
	)

Truncates the file to the given length.

Works just like UNIX ftruncate(2).

Parameters:

	fs	file to truncate
	length	lenght to truncate to

Returns:

0 on success, -1 on error

See also:

ftruncate(2)

off_t jlseek	(	jfs_t *	fs,
		off_t	offset,
		int	whence
	)

Reposition read/write file offset.

Works just like UNIX lseek(2).

Parameters:

	fs	file to change the offset to
	offset	offset to set
	whence	where to count offset from, can be SEEK_SET to count from the beginning of the file, SEEK_CUR to count from the current position, or SEEK_END to count from the end.

Returns:

the new offset counted from the beginning of the file, or -1 on error.