lgetxattr

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 xattr(7).

       getxattr() retrieves the value of the extended attribute identified by
       name and associated with the given path in the filesystem.  The attribute
       value is placed in the buffer pointed to by value; size specifies the
       size of that buffer.  The return value of the call is the number of bytes
       placed in value.

       lgetxattr() is identical to getxattr(), except in the case of a symbolic
       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 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 that was assigned using
       setxattr(2).

       If size is specified as zero, these calls return the current size of the
       named extended attribute (and leave value unchanged).  This can be used
       to determine the size of the buffer that should be supplied in a
       subsequent call.  (But, bear in mind that there is a possibility that the
       attribute value may change between the two calls, so that it is still
       necessary to check the return status from the second call.)

RETURN VALUE
       On success, these calls return a nonnegative value which is the size (in
       bytes) of the extended attribute value.  On failure, -1 is returned and
       errno is set appropriately.

ERRORS
       E2BIG  The size of the attribute value is larger than the maximum size
              allowed; the attribute cannot be retrieved.  This can happen on
              filesystems that support very large attribute values such as
              NFSv4, for example.

       ENODATA
              The named attribute does not exist, or the process has no access
              to this attribute.

       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.

EXAMPLES
       See listxattr(2).

SEE ALSO
       getfattr(1), setfattr(1), listxattr(2), open(2), removexattr(2),
       setxattr(2), stat(2), symlink(7), xattr(7)

COLOPHON
       This page is part of release 5.10 of the Linux man-pages project.  A
       description of the project, information about reporting bugs, and the
       latest version of this page, can be found at
       https://www.kernel.org/doc/man-pages/.




Linux                              2020-06-09                        GETXATTR(2)