acl_extended_file(3)

1ACL_EXTENDED_FILE(3)     BSD Library Functions Manual     ACL_EXTENDED_FILE(3)
2

NAME

4     acl_extended_file, acl_extended_file_nofollow — test for information in
5     ACLs by file name
6

LIBRARY

8     Linux Access Control Lists library (libacl, -lacl).
9

SYNOPSIS

11     #include <sys/types.h>
12     #include <acl/libacl.h>
13
14     int
15     acl_extended_file(const char *path_p);
16
17     int
18     acl_extended_file_nofollow(const char *path_p);
19

DESCRIPTION

21     The acl_extended_file() function returns 1 if the file or directory re‐
22     ferred to by the argument path_p is associated with an extended access
23     ACL, or if the directory referred to by path_p is associated with a de‐
24     fault ACL. The function returns 0 if the file has neither an extended ac‐
25     cess ACL nor a default ACL.
26
27     An extended ACL is an ACL that contains entries other than the three re‐
28     quired entries of tag types ACL_USER_OBJ, ACL_GROUP_OBJ and ACL_OTHER.
29     If the result of the acl_extended_file() function for a file object is 0,
30     then ACLs define no discretionary access rights other than those already
31     defined by the traditional file permission bits.
32
33     Access to the file object may be further restricted by other mechanisms,
34     such as Mandatory Access Control schemes. The access(2) system call can
35     be used to check whether a given type of access to a file object would be
36     granted.
37
38     acl_extended_file_nofollow() is identical to acl_extended_file(), except
39     in the case of a symbolic link, where the link itself is interrogated,
40     not the file that it refers to.  Since symbolic links have no ACL them‐
41     selves, the operation is supposed to fail on them.
42

RETURN VALUE

44     If successful, the acl_extended_file() function returns 1 if the file ob‐
45     ject referred to by path_p has an extended access ACL or a default ACL,
46     and 0 if the file object referred to by path_p has neither an extended
47     access ACL nor a default ACL. Otherwise, the value -1 is returned and the
48     global variable errno is set to indicate the error.
49

ERRORS

51     If any of the following conditions occur, the acl_extended_file() func‐
52     tion returns -1 and sets errno to the corresponding value:
53
54     [EACCES]           Search permission is denied for a component of the
55                        path prefix.
56
57     [ENAMETOOLONG]     The length of the argument path_p is too long.
58
59     [ENOENT]           The named object does not exist or the argument path_p
60                        points to an empty string.
61
62     [ENOTDIR]          A component of the path prefix is not a directory.
63
64     [ENOTSUP]          The file system on which the file identified by path_p
65                        is located does not support ACLs, or ACLs are dis‐
66                        abled.
67

STANDARDS

69     This is a non-portable, Linux specific extension to the ACL manipulation
70     functions defined in IEEE Std 1003.1e draft 17 (“POSIX.1e”, abandoned).
71

AUTHOR

76     Written by Andreas Gruenbacher <andreas.gruenbacher@gmail.com>.
77
78Linux ACL                       March 23, 2002                       Linux ACL