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ACCESS(2)                 FreeBSD System Calls Manual                ACCESS(2)

NAME
     access - check access permissions of a file or pathname

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     #include <unistd.h>

     int
     access(const char *path, int mode);

DESCRIPTION
     The access() function checks the accessibility of the file named by path
     for the access permissions indicated by mode.  The value of mode is the
     bitwise inclusive OR of the access permissions to be checked (R_OK for
     read permission, W_OK for write permission and X_OK for execute/search
     permission) or the existence test, F_OK.  All components of the pathname
     path are checked for access permissions (including F_OK).

     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.

     Even if a process has appropriate privileges and indicates success for
     X_OK, the file may not actually have execute permission bits set.
     Likewise for R_OK and W_OK.

RETURN VALUES
     If 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.

ERRORS
     Access to the file is denied if:

     [ENOTDIR]          A component of the path prefix is not a directory.

     [ENAMETOOLONG]     A component of a pathname exceeded 255 characters, or
                        an entire path name exceeded 1023 characters.

     [ENOENT]           The named file does not exist.

     [ELOOP]            Too many symbolic links were encountered in
                        translating the pathname.

     [EROFS]            Write access is requested for a file on a read-only
                        file system.

     [ETXTBSY]          Write access is requested for a pure procedure (shared
                        text) file presently being executed.

     [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.

     [EFAULT]           Path points outside the process's allocated address
                        space.

     [EIO]              An I/O error occurred while reading from or writing to
                        the file system.

SEE ALSO
     chmod(2), stat(2)

STANDARDS
     The access() function call is expected to conform to IEEE Std 1003.1-1990
     (``POSIX.1'').

CAVEAT
     Access() is a potential security hole and should never be used.

HISTORY
     An access() function call appeared in Version 7 AT&T UNIX.

FreeBSD 11.0-PRERELEASE          April 1, 1994         FreeBSD 11.0-PRERELEASE

NAME | LIBRARY | SYNOPSIS | DESCRIPTION | RETURN VALUES | ERRORS | SEE ALSO | STANDARDS | CAVEAT | HISTORY

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