acl_extended_file (3)

Leading comments

Access Control Lists manual pages

(C) 2002 Andreas Gruenbacher, <a.gruenbacher@bestbits.at>

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(The comments found at the beginning of the groff file "man3/acl_extended_file.3".)

NAME

acl_extended_file, acl_extended_file_nofollow - test for information in ACLs by file name

LIBRARY

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

SYNOPSIS

In sys/types.h In acl/libacl.h Ft int Fn acl_extended_file const char *path_p Ft int Fn acl_extended_file_nofollow const char *path_p

DESCRIPTION

The Fn acl_extended_file function returns 1 if the file or directory referred to by the argument path_p is associated with an extended access ACL, or if the directory referred to by path_p is associated with a default ACL. The function returns 0 if the file has neither an extended access ACL nor a default ACL.

An extended ACL is an ACL that contains entries other than the three required entries of tag types ACL_USER_OBJ, ACL_GROUP_OBJ and ACL_OTHER. If the result of the Fn acl_extended_file function for a file object is 0 then ACLs define no discretionary access rights other than those already defined by the traditional file permission bits.

Access to the file object may be further restricted by other mechanisms, such as Mandatory Access Control schemes. The access(2) system call can be used to check whether a given type of access to a file object would be granted.

Fn acl_extended_file_nofollow is identical to Fn acl_extended_file , except in the case of a symbolic link, where the link itself is interrogated, not the file that it refers to. Since symbolic links have no ACL themselves, the operation is supposed to fail on them.

RETURN VALUE

If successful, the Fn acl_extended_file function returns 1 if the file object referred to by path_p has an extended access ACL or a default ACL, and 0 if the file object referred to by path_p has neither an extended access ACL nor a default ACL. 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 Fn acl_extended_file function returns -1 and sets errno to the corresponding value:

Bq Er EACCES

Search permission is denied for a component of the path prefix.

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 ENOTDIR

A component of the path prefix is not a directory.

Bq Er ENOTSUP

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

STANDARDS

This is a non-portable, Linux specific extension to the ACL manipulation functions defined in IEEE Std 1003.1e draft 17 (lqPOSIX.1erq, abandoned).

SEE ALSO

access(2), acl_get_file3, acl(5)

AUTHOR

Written by An Andreas Gruenbacher Aq a.gruenbacher@bestbits.at .