Chapter 16 - Complete example programs


             The  intent of this chapter is to give several  example
        programs  that  use nearly every capability of  Modula-2  as
        illustrations  of large usable programs.   The programs  are
        usable  utilities,   but  primarily  they  are  intended  to
        illustrate  the method of building up a medium sized program
        from the various constructs studied in the earlier chapters.

                                 BAKLIST.MOD

             This  program generates a list of all files along  with
        their subdirectories. Some files are excluded from the list,
        including  all three files that comprise the DOS system  and
        the  file generated here,  FULLDISK.LST.   This is an  ASCII
        file  that  can be edited with any text editor to  eliminate
        any  files that you do not wish to back up.   It  should  be
        noted that the file,  FULLDISK.LST, is created and filled in
        the  root  directory  of the  default  drive.

             Select  the desired subdirectory that you wish to  back
        up,   and  the  files,  subdirectories,  and  all  of  their
        respective  contents  will be listed in  FULLDISK.LST.   The
        resulting list is then used by BAKCOPY to actually copy  the
        files to a floppy disk.

                                 BAKCOPY.MOD

             This  program  uses FULLDISK.LST to actually  copy  the
        files from the source disk to the target and requests a disk
        change whenever the floppy disk fills up.   It will not copy
        a file larger than that which will fit on one disk, but will
        give a message of which files are not copied.

                                 BAKRSTR.MOD

             This  program will read the files from floppy  back  to
        the  fixed  disk  to  restore it.   It  simply  copies  from
        whatever   directory  they  are  in  to  the   corresponding
        directory  on  the fixed disk,  creating  the  directory  if
        necessary.

                         DIRHELPS.DEF   DIRHELPS.MOD

             This   global  module  contains  several  useful   file
        handling  and  directory  manipulation  procedures.   It  is
        called  by the above three example programs used for  backup
        and  restore of a fixed disk.   These routines are available
        for  your  use  also if you desire to use them  for  a  file
        manipulation  program.   Their main intent however  is  that
        they  be a guide for the student to observe methods used  to
        write library functions.



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                   Chapter 16 - Complete example programs


                         BITOPS.DEF     BITOPS.MOD

             This  module has several generic bit operations such as
        logical  AND,  OR,  etc.  and shift operations.   These  are
        useful  procedures  that  you  can import and  use  in  your
        programs if you are doing bit manipulations.

                         REAL2MON.DEF   REAL2MON.MOD

             This module has a procedure to output REAL data to  the
        monitor in a neat, easy to read format.  It is documented in
        the header of the source files.

                         REAL2FIL.DEF   REAL2FIL.MOD

             This  module has several procedures to output REAL  and
        other data type to a file using the FileSystem MODULE.   The
        various   procedures  are  documented  in  their  respective
        headers.


































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