fgetxattr(2) — Linux manual page


GETXATTR(2)               Linux Programmer's Manual              GETXATTR(2)

NAME         top

       getxattr, lgetxattr, fgetxattr - retrieve an extended attribute value

SYNOPSIS         top

       #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         top

       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         top

       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         top

       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.

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

              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         top

       These system calls have been available on Linux since kernel 2.4;
       glibc support is provided since version 2.3.

CONFORMING TO         top

       These system calls are Linux-specific.

EXAMPLES         top

       See listxattr(2).

SEE ALSO         top

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

COLOPHON         top

       This page is part of release 5.09 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

Linux                            2020-06-09                      GETXATTR(2)

Pages that refer to this page: creat(2)open(2)openat(2)syscalls(2)