NAME¶

acl_get_file — get an ACL by filename

LIBRARY¶

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

SYNOPSIS¶

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

acl_t
acl_get_file(const char *path_p, acl_type_t type);

DESCRIPTION¶

The acl_get_file() function retrieves the access ACL associated with a file or directory, or the default ACL associated with a directory. The pathname for the file or directory is pointed to by the argument path_p. The ACL is placed into working storage and acl_get_file() returns a pointer to that storage.

In order to read an ACL from an object, a process must have read access to the object's attributes.

The value of the argument type is used to indicate whether the access ACL or the default ACL associated with path_p is returned. If type is ACL_TYPE_ACCESS, the access ACL of path_p is returned. If type is ACL_TYPE_DEFAULT, the default ACL of path_p is returned. If type is ACL_TYPE_DEFAULT and no default ACL is associated with the directory path_p, then an ACL containing zero ACL entries is returned. If type specifies a type of ACL that cannot be associated with path_p, then the function fails.

This function may cause memory to be allocated. The caller should free any releasable memory, when the new ACL is no longer required, by calling acl_free(3) with the (void*)acl_t returned by acl_get_file() as an argument.

RETURN VALUE¶

On success, this function returns a pointer to the working storage. On error, a value of (acl_t)NULL is returned, and errno is set appropriately.

ERRORS¶

If any of the following conditions occur, the acl_get_file() function returns a value of (acl_t)NULL 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 type is not ACL_TYPE_ACCESS or ACL_TYPE_DEFAULT.

[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.

[ENOMEM]

The ACL working storage requires more memory than is allowed by the hardware or system-imposed memory management constraints.

[ENOTDIR]

A component of the path prefix is not a directory.

[ENOTSUP]

The file system on which the file identified by path_p is located does not support ACLs, or ACLs are disabled.

STANDARDS¶

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

SEE ALSO¶

acl_free(3), acl_get_entry(3), acl_get_fd(3), acl_set_file(3), acl(5)

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⟩.