package core_unix

Extended attributes are name:value pairs associated with inodes (files, directories, symlinks, etc). They are extensions to the normal attributes which are associated with all inodes in the system (i.e. the 'man 2 stat' data). A complete overview of extended attributes concepts can be found in 'man 5 attr'.

getxattr retrieves the value of the extended attribute identified by name and associated with the given path in the filesystem.

The name includes a namespace prefix - there may be several, disjoint namespaces associated with an individual inode. The value is a chunk of arbitrary textual or binary data.

If the attribute exists, it is returned as Ok string. Several common errors are returned as possible constructors, namely:

• ENOATTR: The named attribute does not exist, or the process has no access to this attribute.
• ERANGE: The size of the value buffer is too small to hold the result.
• ENOTSUP: Extended attributes are not supported by the filesystem, or are disabled.

Many other errors are possible, and will raise an exception. See the man pages for full details.

setxattr sets the value of the extended attribute identified by name and associated with the given path in the filesystem.

how defaults to `Set, in which case the extended attribute will be created if need be, or will simply replace the value if the attribute exists. If how is `Create, then setxattr returns EEXIST if the named attribute exists already. If how is `Replace, then setxattr returns ENOATTR if the named attribute does not already exist.

ENOTSUP means extended attributes are not supported by the filesystem, or are disabled. Many other errors are possible, and will raise an exception. See the man pages for full details.