attr_set(2)
attr_set, attr_setf - set the value of a user attribute of a filesystem object
As shipped in IRIX 6.5.5. Unchanged since IRIX 6.5.
NAME attr_set, attr_setf - set the value of a user attribute of a filesystem object C SYNOPSIS #include <sys/attributes.h> int attr_set (const char *path, const char *attrname, const char *attrvalue, const int valuelength, int flags); int attr_setf (int fd, const char *attrname, const char *attrvalue, const int valuelength, int flags); OVERVIEW The attr group of system calls implement the ability for a user to attach name/value pairs to objects within the filesystem. They could be used to store meta-information about the file. For example "character-set=kanji" could tell a document browser to use the Kanji character set when displaying that document and "thumbnail=..." could provide a reduced resolution overview of a high resolution graphic image. The names can be up to MAXNAMELEN bytes in length, terminated by the first 0 byte. The intent is that they be printable ASCII (or other character set) names for the attribute. The values can be up to ATTR_MAX_VALUELEN (currently 64KB) of arbitrary binary data. Attributes can be attached to all types of inodes: regular files, directories, symbolic links, device nodes, etc. There are 2 disjoint attribute name spaces associated with every filesystem object. They are the root and user address spaces. The root address space is accessable only to the super-user, and then only by specifying a flag argument to the function call. Other users will not see or be able to modify attributes in the root address space. The user address space is protected by the normal file permissions mechanism, so the owner of the file can decide who is able to see and/or modify the value of attributes on any particular file. Attributes are currently supported only in the XFS filesystem type. DESCRIPTION The attr_set and attr_setf functions provide a way to create attributes and set/change their values. Path points to a path name for a filesystem object, and fd refers to the file descriptor associated with a file. If the attribute attrname does not exist, an attribute with the given name and value will be created and associated with that indicated filesystem object. If an attribute with that name already exists on that filesystem object, the existing value is replaced with the new value given in this call. The new attribute value is copied from the attrvalue buffer for a total of valuelength bytes. The flags argument can contain the following symbols bitwise OR'ed together: ATTR_ROOT Look for attrname in the root address space, not in the user address space. (limited to use by super-user only) ATTR_DONTFOLLOW Do not follow symbolic links when resolving a path on an attr_set function call. The default is to follow symbolic links. ATTR_CREATE Return an error (EEXIST) if an attribute of the given name already exists on the indicated filesystem object, otherwise create an attribute with the given name and value. This flag is used to implement a pure create operation, without this flag attr_set will create the attribute if it does not already exist. An error (EINVAL) will be returned if both ATTR_CREATE and ATTR_REPLACE are set in the same call. ATTR_REPLACE Return an error (ENOATTR) if an attribute of the given name does not already exist on the indicated filesystem object, otherwise replace the existing attribute's value with the given value. This flag is used to implement a pure replacement operation, without this flag attr_set will create the attribute if it does not already exist. An error (EINVAL) will be returned if both ATTR_CREATE and ATTR_REPLACE are set in the same call. attr_set will fail if one or more of the following are true: [ENOATTR] The attribute name given is not associated with the indicated filesystem object and the ATTR_REPLACE flag bit was set. [E2BIG] The value of the given attribute is too large, it exceeds the maximum allowable size of an attribute value. [EEXIST] The attribute name given is already associated with the indicated filesystem object and the ATTR_CREATE flag bit was set. [ENOENT] The named file does not exist. [EPERM] The effective user ID does not match the owner of the file and the effective user ID is not super-user. [ENOTDIR] A component of the path prefix is not a directory. [EACCES] Search permission is denied on a component of the path prefix. [EINVAL] A bit was set in the flag argument that is not defined for this system call, or both the ATTR_CREATE and ATTR_REPLACE flags bits were set. [EFAULT] Path, attrname, or attrvalue points outside the allocated address space of the process. [ELOOP] A path name lookup involved too many symbolic links. [ENAMETOOLONG] The length of path exceeds {MAXPATHLEN}, or a pathname component is longer than {MAXNAMELEN}. attr_setf will fail if: [ENOATTR] The attribute name given is not associated with the indicated filesystem object and the ATTR_REPLACE flag bit was set. [E2BIG] The value of the given attribute is too large, it exceeds the maximum allowable size of an attribute value. [EEXIST] The attribute name given is already associated with the indicated filesystem object and the ATTR_CREATE flag bit was set. [EINVAL] A bit was set in the flag argument that is not defined for this system call, or both the ATTR_CREATE and ATTR_REPLACE flags bits were set, or fd refers to a socket, not a file. [EFAULT] Attrname, or attrvalue points outside the allocated address space of the process. [EBADF] Fd does not refer to a valid descriptor. SEE ALSO attr(1), attr_get(2), attr_getf(2), attr_list(2), attr_listf(2) attr_multi(2), attr_multif(2) attr_remove(2), attr_removef(2), DIAGNOSTICS Upon successful completion, a value of 0 is returned. Otherwise, a value of -1 is returned and errno is set to indicate the error.