GETXATTR(2) Linux Programmer's Manual GETXATTR(2)NAME
getxattr, lgetxattr, fgetxattr - retrieve an extended attribute value
SYNOPSIS
#include <sys/types.h>
#include <sys/xattr.h>
ssize_t getxattr(const char *path, const char *name,
void *value, size_t size);
ssize_t lgetxattr(const char *path, const char *name,
void *value, size_t size);
ssize_t fgetxattr(int fd, const char *name,
void *value, size_t size);
DESCRIPTION
Extended attributes are name:value pairs associated with inodes (files,
directories, symbolic links, etc.). They are extensions to the normal
attributes which are associated with all inodes in the system (i.e.,
the stat(2) data). A complete overview of extended attributes concepts
can be found in attr(5).
getxattr() retrieves the value of the extended attribute identified by
name and associated with the given path in the filesystem. The length
of the attribute value is returned.
lgetxattr() is identical to getxattr(), except in the case of a sym‐
bolic link, where the link itself is interrogated, not the file that it
refers to.
fgetxattr() is identical to getxattr(), only the open file referred to
by fd (as returned by open(2)) is interrogated in place of path.
An extended attribute name is a simple null-terminated string. The
name includes a namespace prefix; there may be several, disjoint names‐
paces associated with an individual inode. The value of an extended
attribute is a chunk of arbitrary textual or binary data of specified
length.
An empty buffer of size zero can be passed into these calls to return
the current size of the named extended attribute, which can be used to
estimate the size of a buffer which is sufficiently large to hold the
value associated with the extended attribute.
The interface is designed to allow guessing of initial buffer sizes,
and to enlarge buffers when the return value indicates that the buffer
provided was too small.
RETURN VALUE
On success, a positive number is returned indicating the size of the
extended attribute value. On failure, -1 is returned and errno is set
appropriately.
ERRORS
ENOATTR
The named attribute does not exist, or the process has no access
to this attribute. (ENOATTR is defined to be a synonym for ENO‐
DATA in <attr/xattr.h>.)
ENOTSUP
Extended attributes are not supported by the filesystem, or are
disabled.
ERANGE The size of the value buffer is too small to hold the result.
In addition, the errors documented in stat(2) can also occur.
VERSIONS
These system calls have been available on Linux since kernel 2.4; glibc
support is provided since version 2.3.
CONFORMING TO
These system calls are Linux-specific.
SEE ALSOgetfattr(1), setfattr(1), listxattr(2), open(2), removexattr(2), setx‐
attr(2), stat(2), attr(5), symlink(7)COLOPHON
This page is part of release 3.58 of the Linux man-pages project. A
description of the project, and information about reporting bugs, can
be found at http://www.kernel.org/doc/man-pages/.
Linux 2014-02-06 GETXATTR(2)