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GETXATTR(2)                      System calls                      GETXATTR(2)



NAME
       getxattr, lgetxattr, fgetxattr - retrieve an extended attribute value

SYNOPSIS
       #include <sys/types.h>
       #include <attr/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 filedes, const char *name,
                            void *value, size_t size);

DESCRIPTION
       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 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 symbolic link, where the link  itself  is  interro-
       gated, not the file that it refers to.

       fgetxattr is identical to getxattr, only the open file pointed to by filedes (as returned by open(2)) is inter-
       rogated 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 namespaces 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.

       If the named attribute does not exist, or the process has no access to this attribute, errno is set to ENOATTR.

       If the size of the value buffer is too small to hold the result, errno is set to ERANGE.

       If extended attributes are not supported by the filesystem, or are disabled, errno is set to ENOTSUP.

       The errors documented for the stat(2) system call are also applicable here.

AUTHORS
       Andreas  Gruenbacher,  <a.gruenbacherATbestbits.at>  and  the SGI XFS development team, <linux-xfsAToss.com>.
       Please send any bug reports or comments to these addresses.

SEE ALSO
       getfattr(1), setfattr(1), open(2), stat(2), setxattr(2), listxattr(2), removexattr(2), and attr(5).



Dec 2001                      Extended Attributes                  GETXATTR(2)