question: protected int decodeLinePrefix ( PushbackInputStream inStream , OutputStream outStream ) throws IOException { int c ; c = inStream . read ( ) ; if ( c == ' ' ) { c = inStream . read ( ) ; c = inStream . read ( ) ; if ( ( c != '\n' ) && ( c != - 1 ) ) inStream . unread ( c ) ; throw new CEStreamExhausted ( ) ; } else if ( c == - 1 ) { throw new CEFormatException ( "UUDecoder: Short Buffer." ) ; } c = ( c - ' ' ) & 0x3f ; if ( c > bytesPerLine ( ) ) { throw new CEFormatException ( "UUDecoder: Bad Line Length." ) ; } return ( c ) ; }
target:  In uuencoded buffers, encoded lines start with a character that represents the number of bytes encoded in this line. The last line of input is always a line that starts with a single space character, which would be a zero length line.