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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 $
40 .Nd check access permissions of a file or pathname
46 .Fn access "const char *path" "int mode"
50 function checks the accessibility of the
53 for the access permissions indicated by
57 is the bitwise inclusive OR of the access permissions to be
62 for write permission and
64 for execute/search permission) or the existence test,
66 All components of the pathname
68 are checked for access permissions (including
71 The real user ID is used in place of the effective user ID
72 and the real group access list
73 (including the real group ID) are
74 used in place of the effective ID for verifying permission.
76 Even if a process has appropriate privileges and indicates success for
78 the file may not actually have execute permission bits set.
86 cannot be found or if any of the desired access modes would
87 not be granted, then a -1 value is returned; otherwise
88 a 0 value is returned.
90 Access to the file is denied if:
93 A component of the path prefix is not a directory.
94 .It Bq Er ENAMETOOLONG
95 A component of a pathname exceeded 255 characters,
96 or an entire path name exceeded 1023 characters.
98 The named file does not exist.
100 Too many symbolic links were encountered in translating the pathname.
102 Write access is requested for a file on a read-only file system.
104 Write access is requested for a pure procedure (shared text)
105 file presently being executed.
107 Permission bits of the file mode do not permit the requested
108 access, or search permission is denied on a component of the
109 path prefix. The owner of a file has permission checked with
110 respect to the ``owner'' read, write, and execute mode bits,
111 members of the file's group other than the owner have permission
112 checked with respect to the ``group'' mode bits, and all
113 others have permissions checked with respect to the ``other''
117 points outside the process's allocated address space.
119 An I/O error occurred while reading from or writing to the file system.
127 function call is expected to conform to
131 is a potential security hole due to race conditions and
132 should never be used.
133 Setuid and setgid applications should restore the effective uid or gid
134 and perform actions directly rather than use
136 to simulate access checks for the real user of group id.
140 function call appeared in