Linking with the library

At a Starlink node the library is available as an archive of object modules. Since it is intended primarily for Starlink application packages, the link command used is most probably `alink'. In that case link as follows:

   % alink a-task.o -L/star/lib `pda_link_adam`

The library can equally well be used by ordinary programs:

   % f77 program.f -L/star/lib `pda_link`

The pda_link and pda_link_adam scripts results in your program being linked with the Starlink Error Message Service (EMS). When an error report is to be made, the library will call EMS_SETC and EMS_REP, and you have to link your program against a version of these routines.

If you do not want to link against EMS, then you can provide your own replacements for the two EMS routines. Use the following code:

*  File name might be mymsg.f

      SUBROUTINE EMS_SETC( MESSG )
      CHARACTER * ( * ) MESSG
      WRITE( *, * ) MESSG
      END

      SUBROUTINE EMS_REP( MNAME, MESSG, STATUS )
      CHARACTER * ( * ) MNAME, MESSG
      INTEGER STATUS
      END

Then link:

   % f77 program.f mymsg.f -L/star/lib -lpda

Finally, if your site is not a Starlink site, you can customise the library as such to make EMS obsolete. For this you have to replace the error handling routine PDA_XERMSG in the library. The new code should be

*  File name would be pda_xermsg.f

      SUBROUTINE PDA_XERMSG( LIBRAR, SUBROU, MESSG, NERR, LEVEL, STATUS )

      CHARACTER * ( * ) LIBRAR, SUBROU, MESSG
      INTEGER NERR, LEVEL
      INTEGER STATUS

      WRITE( *, * ) LIBRAR // '/' // SUBROU // ': ' // MESSG
      STATUS = 1

      END

You might also modify the link script pda_link so that it does not refer to ems_link any more and does not execute any awk command:

#  N.B. the previous line should be blank.
      echo -lpda