__LINE__

 This is not really a system variable, but rather it is a macro which
 CS.EXE will replace by an integer constant equal to the current line
 number in the file which is being compiled. This will be done while
 CS is compiling the script file, so TELIX.EXE will never know anything
 about this and the value by which __LINE__ is replaced can only be
 changed by recompiling.

   Example:

      printsc ( "This is file " );
      printsc ( __FILE__ );
      prints ( " and line number " );
      printn ( __LINE__ );
      printsc ( ", compiled on " );
      printsc ( __DATE__ );
      prints ( " at " );
      printn ( __TIME__ );