NAME

acl_set_file — set an ACL by filename

LIBRARY

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

SYNOPSIS

#include <sys/types.h>
#include <sys/acl.h>

int
acl_set_file(const char *path_p, acl_type_t type, acl_t acl);

DESCRIPTION

The 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 pointed to by the argument path_p.

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_valid(3) 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 acl_set_file() function removes any default ACL associated with the directory referred to by the path_p parameter.

RETURN VALUE

The acl_set_file() function returns the value 0 if successful; otherwise the value -1 is returned and the global variable errno is set to indicate the error.

ERRORS

If any of the following conditions occur, the acl_set_file() function returns -1 and sets errno to the corresponding value:

[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.

[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.

[ENAMETOOLONG]

The length of the argument path_p is too long.

[ENOENT]

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

[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.

[ENOTDIR]

A component of the path prefix is not a directory.

[ENOTSUP]

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.

[EPERM]

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

[EROFS]

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

STANDARDS

IEEE Std 1003.1e draft 17 (“POSIX.1e”, abandoned)

The behavior of 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 acl_get_file() can be passed to acl_set_file(). The POSIX.1e function for removing a default ACL is acl_delete_def_file().

AUTHOR

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