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ACL_SET_FILE

Section: C Library Functions (3)
Index Return to Main Contents

BSD mandoc
Linux ACL

NAME

acl_set_file acl_set_file_at - set an ACL by filename

LIBRARY

Linux Access Control Lists library (libacl, -lacl).

SYNOPSIS

In sys/types.h In sys/acl.h Ft int Fo acl_set_file Fa const char *path_p Fa acl_type_t type Fa acl_t acl Fc Ft int Fo acl_set_file_at Fa int dirfd Fa const char *path_p Fa int at_flags Fa acl_type_t type Fa acl_t acl Fc

DESCRIPTION

The Fn acl_set_file function associates an access ACL with a file or directory, or associates a default ACL with a directory. The pathname for the file or directory is given in the argument path_p If path_p is a symbolic link, Fn acl_set_file operates on the file or directory the link refers to.

The effective user ID of the process must match the owner of the file or directory or the process must have the CAP_FOWNER capability for the request to succeed.

The value of the argument type is used to indicate whether the access ACL or the default ACL associated with path_p is being set. If the type parameter is ACL_TYPE_ACCESS the access ACL of path_p shall be set. If the type parameter is ACL_TYPE_DEFAULT the default ACL of path_p shall be set. If the argument type specifies a type of ACL that cannot be associated with path_p then the function fails.

The acl parameter must reference a valid ACL according to the rules described on the acl_valid3 manual page if the type parameter is ACL_TYPE_ACCESS and must either reference a valid ACL or an ACL with zero ACL entries if the type parameter is ACL_TYPE_DEFAULT If the acl parameter references an empty ACL, then the Fn acl_set_file function removes any default ACL associated with the directory referred to by the path_p parameter.

Fn acl_set_file_at

The Fn acl_set_file_at function operates in exactly the same way as Fn acl_set_file , except for the differences described here.

If the pathname given in path_p is relative, then it is interpreted relative to the directory referred to by the file descriptor dirfd (rather than relative to the current working directory of the calling process, as is done by Fn acl_set_file ) .

If path_p is relative and dirfd is the special value AT_FDCWD then path_p is interpreted relative to the current working directory of the calling process (like Fn acl_set_file ) .

If path_p is absolute, then dirfd is ignored.

The at_flags argument can either be 0, or include one or more of the following flags ORed:

AT_EMPTY_PATH: If path_p is an empty string, operate on the file referred to by dirfd (which may have been obtained using the open(2) O_PATH flag). In this case, dirfd can refer to any type of file, not just a directory, and the behavior of Fn acl_set_file_at is similar to that of Fn acl_set_fd .
AT_SYMLINK_NOFOLLOW: If path_p refers to a symbolic link, do not dereference it: instead, fail the operation and set the global variable errno to Er ENOTSUP . This indicates that the symbolic link cannot have ACLs.

RETURN VALUE

Rv -std acl_set_file acl_set_file_at

ERRORS

If any of the following conditions occur, the Fn acl_set_file and Fn acl_set_file_at functions return -1 and set errno to the corresponding value:

Bq Er EACCES

Search permission is denied for a component of the path prefix or the object exists and the process does not have appropriate access rights.

Argument type specifies a type of ACL that cannot be associated with path_p

Bq Er EBADF

The argument path_p is relative but the argument dirfd is neither AT_FDCWD nor a valid file descriptor.

Bq Er EINVAL

The argument acl does not point to a valid ACL.

The ACL has more entries than the file referred to by path_p can obtain.

The type parameter is not ACL_TYPE_ACCESS or ACL_TYPE_DEFAULT

The type parameter is ACL_TYPE_DEFAULT but the file referred to by path_p is not a directory.

An invalid flag was specified in the at_flags argument.

Bq Er ENAMETOOLONG

The length of the argument path_p is too long.

Bq Er ENOENT

The named object does not exist or the argument path_p points to an empty string.

Bq Er ENOSPC

The directory or file system that would contain the new ACL cannot be extended or the file system is out of file allocation resources.

Bq Er ENOTDIR

A component of the path prefix is not a directory.

The argument path_p is relative and the argument dirfd is a file descriptor referring to a file other than a directory.

Bq Er ENOTSUP

The argument at_flags includes the flag AT_SYMLINK_NOFOLLOW and path_p is a symbolic link.

The file identified by path_p cannot be associated with the ACL because the file system on which the file is located does not support this.

Bq Er EPERM

The process does not have appropriate privilege to perform the operation to set the ACL.

Bq Er EROFS

This function requires modification of a file system which is currently rea-only.

STANDARDS

IEEE Std 1003.1e draft 17 (lqPOSIX.1erq, abandoned)

The behavior of Fn acl_set_file when the acl parameter refers to an empty ACL and the type parameter is ACL_TYPE_DEFAULT is an extension in the Linux implementation, in order that all values returned by Fn acl_get_file can be passed to Fn acl_set_file . The POSIX.1e function for removing a default ACL is Fn acl_delete_def_file .

Function Fn acl_get_file_at is a Linux specific extension.

AUTHOR

Derived from the FreeBSD manual pages written by An Robert N M Watson Aq rwatson@FreeBSD.org , and adapted for Linux by An Andreas Gruenbacher Aq andreas.gruenbacher@gmail.com .