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32 .\" @(#)access.2 8.2 (Berkeley) 4/1/94
33 .\" $FreeBSD: src/lib/libc/sys/access.2,v 1.7.2.5 2002/10/12 22:02:53 rwatson Exp $
34 .\" $DragonFly: src/lib/libcr/sys/Attic/access.2,v 1.2 2003/06/17 04:26:47 dillon Exp $
41 .Nd check access permissions of a file or pathname
47 .Fn access "const char *path" "int mode"
51 function checks the accessibility of the
54 for the access permissions indicated by
58 is the bitwise inclusive OR of the access permissions to be
63 for write permission and
65 for execute/search permission) or the existence test,
67 All components of the pathname
69 are checked for access permissions (including
72 The real user ID is used in place of the effective user ID
73 and the real group access list
74 (including the real group ID) are
75 used in place of the effective ID for verifying permission.
77 Even if a process has appropriate privileges and indicates success for
79 the file may not actually have execute permission bits set.
87 cannot be found or if any of the desired access modes would
88 not be granted, then a -1 value is returned; otherwise
89 a 0 value is returned.
91 Access to the file is denied if:
94 A component of the path prefix is not a directory.
95 .It Bq Er ENAMETOOLONG
96 A component of a pathname exceeded 255 characters,
97 or an entire path name exceeded 1023 characters.
99 The named file does not exist.
101 Too many symbolic links were encountered in translating the pathname.
103 Write access is requested for a file on a read-only file system.
105 Write access is requested for a pure procedure (shared text)
106 file presently being executed.
108 Permission bits of the file mode do not permit the requested
109 access, or search permission is denied on a component of the
110 path prefix. The owner of a file has permission checked with
111 respect to the ``owner'' read, write, and execute mode bits,
112 members of the file's group other than the owner have permission
113 checked with respect to the ``group'' mode bits, and all
114 others have permissions checked with respect to the ``other''
118 points outside the process's allocated address space.
120 An I/O error occurred while reading from or writing to the file system.
128 function call is expected to conform to
132 is a potential security hole due to race conditions and
133 should never be used.
134 Setuid and setgid applications should restore the effective uid or gid
135 and perform actions directly rather than use
137 to simulate access checks for the real user of group id.
141 function call appeared in