Function 4300h          Get File Attributes

    Returns the attributes for a specified file or directory.

        Entry   AX    = 4300h
                DS:DX = Pointer to filespec (ASCIIZ string)

        Return  CX = File attributes
                or
                AX = Error code, if CF is set
                     | 01h Invalid function
                     | 02h File not found
                     | 03h Path not found
                     | 05h Access denied

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    The file specification must be a valid DOS file name or directory
    name and cannot contain wildcards.

    The file attributes returned in the CX register can be a
    combination (OR'ed) of the following values:

        attr_normal     = 00h   File can be read from or written to
        attr_readonly   = 01h   File can be read from but not written to
        attr_hidden     = 02h   File/directory is hidden and does not
                                appear in a directory listing
        attr_system     = 04h   File/directory is a system file
        attr_volume     = 08h   Filename is the current volume label
                                for the media
        attr_directory  = 10h   Filename identifies a directory,
                                not a file
        attr_archive    = 20h   File has been modified