ACCESS(2)               COMMAND REFERENCE               ACCESS(2)



NAME
     access - determine accessibility of file

SYNOPSIS
     #include <sys/file.h>

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

DESCRIPTION
     Access checks the given file path for accessibility
     according to mode.  Mode is the inclusive or of the
     following values, defined in <sys/file.h>:

          #define   R_OK 4    * test for read permission *
          #define   W_OK 2    * test for write permission *
          #define   X_OK 1    * test for execute (search) permission *
          #define   F_OK 0    * test for presence of file *

     Specifying mode as F_OK (i.e. 0) 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-user-id programs.

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

DIAGNOSTICS
     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.

     [ENAMETOOLONG]
         The argument path is too long.

     [ENOENT]
         The named file does not exist.

     [ENOASCII]
         The argument path contains a byte with the high-order
         bit set.

     [ELOOP]



Printed 10/17/86                                                1

ACCESS(2)               COMMAND REFERENCE               ACCESS(2)



         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 that is 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.  If the file is located on a remote host, this
         error code will be returned if the local host name and
         local user name does not appear in /usr/lib/dfs/access
         on the remote machine.  See

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

     [EDFSNOSUCHHOST]
         The pathname referenced a remote host, but when we
         broadcast a request for its address, no host responded.

RETURN VALUE
     Upon successful completion, a value of 0 is returned.
     Otherwise, a value of -1 is returned and errno is set to
     indicate the error.

SEE ALSO
     chmod(2), stat(2).















Printed 10/17/86                                                2

%%index%%
na:72,76;
sy:148,472;
de:620,1207;
di:1827,479;2450,1336;
rv:3786,236;
se:4022,109;
%%index%%000000000117