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+.\" Copyright (c) 1980, 1991, 1993
+.\"	The Regents of the University of California.  All rights reserved.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\" 3. All advertising materials mentioning features or use of this software
+.\"    must display the following acknowledgement:
+.\"	This product includes software developed by the University of
+.\"	California, Berkeley and its contributors.
+.\" 4. Neither the name of the University nor the names of its contributors
+.\"    may be used to endorse or promote products derived from this software
+.\"    without specific prior written permission.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.\"     @(#)access.2	8.2 (Berkeley) 4/1/94
+.\"
+.Dd April 1, 1994
+.Dt ACCESS 2
+.Os BSD 4
+.Sh NAME
+.Nm access
+.Nd check access permissions of a file or pathname
+.Sh SYNOPSIS
+.Fd #include <unistd.h>
+.Ft int
+.Fn access "const char *path" "int mode"
+.Sh DESCRIPTION
+The
+.Fn access
+function checks the accessibility of the
+file named by
+.Fa path
+for the access permissions indicated by
+.Fa mode .
+The value of
+.Fa mode
+is the bitwise inclusive OR of the access permissions to be
+checked
+.Pf ( Dv R_OK
+for read permission,
+.Dv W_OK
+for write permission and
+.Dv X_OK
+for execute/search permission) or the existence test,
+.Dv F_OK .
+All components of the pathname
+.Fa path
+are checked for access permissions (including
+.Dv F_OK ) .
+.Pp
+The real user ID is used in place of the effective user ID
+and the real group access list
+(including the real group ID) are
+used in place of the effective ID for verifying permission.
+.Pp
+Even if a process has appropriate privileges and indicates success for
+.Dv X_OK ,
+the file may not actually have execute permission bits set.
+Likewise for
+.Dv R_OK
+and
+.Dv W_OK .
+.Sh RETURN VALUES
+If
+.Fa path
+cannot be found or if any of the desired access modes would
+not be granted, then a -1 value is returned; otherwise
+a 0 value is returned.
+.Sh ERRORS
+Access to the file is denied if:
+.Bl -tag -width Er
+.It Bq Er ENOTDIR
+A component of the path prefix is not a directory.
+.It Bq Er EINVAL
+The pathname contains a character with the high-order bit set.
+.It Bq Er ENAMETOOLONG
+A component of a pathname exceeded 255 characters,
+or an entire path name exceeded 1023 characters.
+.It Bq Er ENOENT
+The named file does not exist.
+.It Bq Er ELOOP
+Too many symbolic links were encountered in translating the pathname.
+.It Bq Er EROFS
+Write access is requested for a file on a read-only file system.
+.It Bq Er ETXTBSY
+Write access is requested for a pure procedure (shared text)
+file presently being executed.
+.It Bq Er EACCES
+Permission bits of the file mode do not permit the requested
+access, or search permission is denied on a component of the
+path prefix.  The owner of a file has permission checked with
+respect to the ``owner'' read, write, and execute mode bits,
+members of the file's group other than the owner have permission
+checked with respect to the ``group'' mode bits, and all
+others have permissions checked with respect to the ``other''
+mode bits.
+.It Bq Er EFAULT
+.Fa Path
+points outside the process's allocated address space.
+.It Bq Er EIO
+An I/O error occurred while reading from or writing to the file system.
+.El
+.Sh SEE ALSO
+.Xr chmod 2 ,
+.Xr stat 2
+.Sh STANDARDS
+.Fn Access
+conforms to IEEE Std 1003.1-1988
+.Pq Dq Tn POSIX .
+.Sh CAVEAT
+.Fn Access
+is a potential security hole and
+should never be used.