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The AtheOS higlevel filesystem API

Compounds
class	os::Directory
	Filesystem directory class. More...
class	os::DirIterator
class	os::File
class	os::FileReference
	Semi persistent reference to a file. More...
class	os::FSNode
	Lowlevel filesystem node class. More...
class	os::NodeMonitor
	Filesystem node monitor. More...
class	os::Path
class	os::SeekableIO
class	os::StreamableIO
class	os::SymLink
	Symbolic link handling class. More...
class	os::TempFile

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Detailed Description

This sections will take you trough the AtheOS highlevel filesystem API. AtheOS have both a low-level API that is mostly POSIX/ANSI compliant and is available to both C and C++ programs. In addition C++ programs can take advantage of the more highlevel C++ filesystem API to get easy access to the filesystem.

This section will concentrate mostly on the highlevel C++ API. To find documentation of the lowlevel API take a look at the AtheOS syscall documentation and possible any POSIX/ANSI documentation you might have available. Since the syscall and libc functions still are very poorly documented and since many of them are compliant with the POSIX and ANSI standards I recommend locating the standard "man" pages from a BSD or Linux distribution and install them under AtheOS. The "man" utility is part of the standard AtheOS installation so simply adding the install location to the MANPATH environment variable will give you easy access to the documentation.

The AtheOS filesystem is organised much like the UNIX filesystem. The entire filesystem have exactly one root named "/" and all other nodes in the FS can be located by traversing from here. Since AtheOS support's mounting an arbritary number of filesystems (or volumes) simultanously a mechanism is needed to "mount" one filesystem inside another. This mechanism is called "mount points". A mount point is simply a existing directory in one of the already mounted filesystems. When a new FS is mounted on a directory that directory will serve as the root of the new filesystem and the previous content (if any) of the mount point will be inaccessible until the new FS is unmounted.

There is two main differences between a normal UNIX filesystem and the AtheOS filesystem. The first is the virtual root-FS, the second is the virtual device-FS. The root directory in AtheOS is not located on a regular filesystem and is not persistant during reboots. The root-FS is only backed in RAM and only support directories (used as mount points) and symlinks. The boot-FS is mounted as /boot/ and the most of the time the FS is accessed through a set of symlinks created in the root by the bootup scripts. Normally extra volumes are also mounted in this virtual root-FS. The virtual device-FS is mounted as /dev/ and controll the AtheOS device drivers. The device-FS can be hierarchial to categorice the device drivers. All nodes inside the device-FS is created by the kernel itself on request from the device-drivers.

NOTE: Throughout this documentation the name "file" might be used on any nodes located in the FS so a "file" might not be a regular file but can also be a directory or symlink depending on the context where the name is used.

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