access(2)                                               access(2)



     NAME
          access - determine accessibility of a file

     SYNOPSIS
          int access (path, amode)
          char* path;
          int amode;

     DESCRIPTION
          path points to a path name naming a file.  access checks the
          named file for accessibility according to the bit pattern
          contained in amode, using the real user ID in place of the
          effective user ID and the real group ID in place of the
          effective group ID.  The bit pattern contained in amode is
          constructed as follows:

               04   read
               02   write
               01   execute (search)
               00   check existence of file

          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.

          [ENOENT]     Read, write, or execute (search) permission is
                       requested for a null path name.

          [ENOENT]     The named file does not exist.

          [EACCES]     Search permission is denied on a component of
                       the path prefix.

          [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.

                       Note: If you are running an NFS system and you
                       are accessing a shared binary remotely, it is
                       possible that you will not get this errno.
                       [EACCESS] Permission bits of the file mode do
                       not permit the requested access.

          [EFAULT]     path points outside the allocated address space
                       for the process.

          The owner of a file has permission checked with respect to



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     access(2)                                               access(2)



          the ``owner'' read, write, and execute mode bits Members of
          the file's group other than the owner have permissions
          checked with respect to the ``group'' mode bits,
           and all others have permissions checked with respect to the
          ``other'' mode bits.

          The super-user is always granted execute permission even
          though (1) execute permission is meaningful only for
          directories and regular files, and (2) exec requires that at
          least one execute mode bit be set for regular file to be
          executable.

          Notice that it is only access bits that are checked.  A
          directory may be announced as writable by access, but an
          attempt to open it for writing will fail because it is not
          allowed to write into the directory structure itself,
          although files may be created there.  A file may look
          executable, but exec will fail unless it is in proper
          format.

     RETURN VALUE
          If the requested access is permitted, 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).




























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