4.3BSD-Reno/share/man/cat2/access.0

ACCESS(2)		      1990			ACCESS(2)



NNAAMMEE
     access - determine accessibility of file

SSYYNNOOPPSSIISS
     ##iinncclluuddee <<uunniissttdd..hh>>

     aacccceessssiibbllee == aacccceessss((ppaatthh,, mmooddee))
     iinntt aacccceessssiibbllee;;
     cchhaarr **ppaatthh;;
     iinntt mmooddee;;

DDEESSCCRRIIPPTTIIOONN
     _A_c_c_e_s_s checks the given file _p_a_t_h for accessibility accord-
     ing to _m_o_d_e, which 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.  Specifying _m_o_d_e as F_OK tests
     whether the directories leading to the file can be searched
     and the file exists.

     The real user ID and the group access list (including the
     real group ID) are used in verifying permission, so this
     call is useful to set-UID programs.

     Notice that only access bits are checked.	A directory may
     be indicated as writable by _a_c_c_e_s_s, but an attempt to open
     it for writing will fail (although files may be created
     there); a file may look executable, but _e_x_e_c_v_e will fail
     unless it is in proper format.

RREETTUURRNN VVAALLUUEE
     If _p_a_t_h 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.

EERRRROORRSS
     Access to the file is denied if one or more of the following
     are true:

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

     [EINVAL]	    The pathname contains a character with the
		    high-order bit set.

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

     [ENOENT]	    The named file does not exist.

     [EACCES]	    Search permission is denied for a component



Printed 7/27/90                May				1






ACCESS(2)		      1990			ACCESS(2)



		    of the path prefix.

     [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 pro-
		    cedure (shared text) file that is being exe-
		    cuted.

     [EACCES]	    Permission bits of the file mode do not per-
		    mit the requested access, or search permis-
		    sion 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 per-
		    mission checked with respect to the ``group''
		    mode bits, and all others have permissions
		    checked with respect to the ``other'' mode
		    bits.

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

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

SSEEEE AALLSSOO
     chmod(2), stat(2)























Printed 7/27/90                May				2