.\" Access Control Lists manual pages .\" .\" (C) 2002-2026 Andreas Gruenbacher .\" .\" This is free documentation; you can redistribute it and/or .\" modify it under the terms of the GNU General Public License as .\" published by the Free Software Foundation; either version 2 of .\" the License, or (at your option) any later version. .\" .\" The GNU General Public License's references to "object code" .\" and "executables" are to be interpreted as the output of any .\" document formatting or typesetting system, including .\" intermediate and printed output. .\" .\" This manual is distributed in the hope that it will be useful, .\" but WITHOUT ANY WARRANTY; without even the implied warranty of .\" MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the .\" GNU General Public License for more details. .\" .\" You should have received a copy of the GNU General Public .\" License along with this manual. If not, see .\" . .\" .Dd June 5, 2026 .Dt ACL_GET_FILE 3 .Os "Linux ACL" .Sh NAME .Nm acl_get_file , .Nm acl_get_file_at .Nd get an ACL by filename .Sh LIBRARY Linux Access Control Lists library (libacl, \-lacl). .Sh SYNOPSIS .In sys/types.h .In sys/acl.h .Ft acl_t .Fo acl_get_file .Fa "const char *path_p" .Fa "acl_type_t type" .Fc .Ft acl_t .Fo acl_get_file_at .Fa "int dirfd" .Fa "const char *path_p" .Fa "int at_flags" .Fa "acl_type_t type" .Fc .Sh DESCRIPTION The .Fn 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 given in the argument .Va path_p . If .Va path_p is a symbolic link, .Fn acl_get_file returns information about the file or directory the link refers to. .Pp The ACL is placed into working storage and .Fn acl_get_file returns a pointer to that storage. .Pp In order to read an ACL from an object, a process must have read access to the object's attributes. .Pp The value of the argument .Va type is used to indicate whether the access ACL or the default ACL associated with .Va path_p is returned. If .Va type is .Dv ACL_TYPE_ACCESS , the access ACL of .Va path_p is returned. If .Va type is .Dv ACL_TYPE_DEFAULT , the default ACL of .Va path_p is returned. If .Va type is .Dv ACL_TYPE_DEFAULT and no default ACL is associated with the directory .Va path_p , then an ACL containing zero ACL entries is returned. If .Va type specifies a type of ACL that cannot be associated with .Va path_p , then the function fails. .Pp 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 .Xr acl_free 3 with the .Va (void*)acl_t returned by .Fn acl_get_file as an argument. .Ss Fn acl_get_file_at The .Fn acl_get_file_at function operates in exactly the same way as .Fn acl_get_file , except for the differences described here. .Pp If the pathname given in .Va path_p is relative, then it is interpreted relative to the directory referred to by the file descriptor .Va dirfd (rather than relative to the current working directory of the calling process, as is done by .Fn acl_get_file ) . .Pp If .Va path_p is relative and .Va dirfd is the special value .Dv AT_FDCWD , then .Va path_p is interpreted relative to the current working directory of the calling process (like .Fn acl_get_file ) . .Pp If .Va path_p is absolute, then .Va dirfd is ignored. .Pp The .Va at_flags argument can either be 0, or include one or more of the following flags ORed: .Bl -tag .It Dv AT_EMPTY_PATH If .Va path_p is an empty string, operate on the file referred to by .Va dirfd (which may have been obtained using the .Xr open 2 .Dv O_PATH flag). In this case, .Va dirfd can refer to any type of file, not just a directory, and the behavior of .Fn acl_get_file_at is similar to that of .Fn acl_get_fd . .It Dv AT_SYMLINK_NOFOLLOW If .Va path_p refers to a symbolic link, do not dereference it: instead, fail the operation and set the global variable .Va errno to .Er ENOTSUP . This indicates that the symbolic link cannot have ACLs. .El .Sh RETURN VALUE On success, the .Fn acl_get_file and .Fn acl_get_file_at functions return a pointer to the working storage. On error, a value of .Li (acl_t)NULL is returned, and .Va errno is set appropriately. .Sh ERRORS If any of the following conditions occur, the .Fn acl_get_file and .Fn acl_get_file_at functions return a value of .Li (acl_t)NULL and set .Va errno to the corresponding value: .Bl -tag -width Er .It 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. .Pp Argument .Va type specifies a type of ACL that cannot be associated with .Va path_p . .It Bq Er EBADF The argument .Va path_p is relative but the argument .Va dirfd is neither .Dv AT_FDCWD nor a valid file descriptor. .It Bq Er EINVAL The argument .Va type is not .Dv ACL_TYPE_ACCESS or .Dv ACL_TYPE_DEFAULT . .Pp An invalid flag was specified in the .Va at_flags argument. .It Bq Er ENAMETOOLONG The length of the argument .Va path_p is too long. .It Bq Er ENOENT The named object does not exist or the argument .Va path_p points to an empty string. .It Bq Er ENOMEM The ACL working storage requires more memory than is allowed by the hardware or system-imposed memory management constraints. .It Bq Er ENOTDIR A component of the path prefix is not a directory. .Pp The argument .Va path_p is relative and the argument .Va dirfd is a file descriptor referring to a file other than a directory. .It Bq Er ENOTSUP The argument .Va at_flags includes the flag .Dv AT_SYMLINK_NOFOLLOW and .Va path_p is a symbolic link. .Pp The file system on which the file identified by .Va path_p is located does not support ACLs, or ACLs are disabled. .El .Sh STANDARDS IEEE Std 1003.1e draft 17 (\(lqPOSIX.1e\(rq, abandoned) .Pp Function .Fn acl_get_file_at is a Linux specific extension. .Sh SEE ALSO .Xr acl_free 3 , .Xr acl_get_entry 3 , .Xr acl_get_fd 3 , .Xr acl_set_file 3 , .Xr acl 5 .Sh 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 .