sysread FILEHANDLE,SCALAR,LENGTH,OFFSET
sysread FILEHANDLE,SCALAR,LENGTH

...

        An OFFSET may be specified to place the read data at some place in
        the string other than the beginning. A negative OFFSET specifies
        placement at that many characters counting backwards from the end
        of the string. A positive OFFSET greater than the length of SCALAR
        results in the string being padded to the required size with "\0"
        bytes before the result of the read is appended.