APPNOTE: Accessing Command-Line Arguments with FORTRAN (65236)

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   Microsoft Product Support Services Application Note (Text File)
        HF0220: ACCESSING COMMAND-LINE ARGUMENTS WITH FORTRAN
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                                                   Revision Date: 8/91
                                                      No Disk Included
The following information applies to Microsoft FORTRAN versions 4.0,
4.01, and 4.1.
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Summary

This application note explains how to access command-line arguments with Microsoft FORTRAN versions 4.0, 4.01, and 4.1.

Below is the code for the following FORTRAN files:

   Filename      Description
  --------      -----------

  PSPTST.FOR    Main program that contains the INTERFACE to DMPCMD and
                calls DMPCMD

  DMPCMD.FOR    Subroutine that prints the contents of the command
                line

  Note: DMPCMD must be compiled in a separate source file.

How to Use PSPTST

Use the following command to compile the two programs:

  
   FL PSPTST.FOR DMPCMD.FOR

If PSPTST is invoked with a command line such as

  PSPTST hello

the output will be as follows:

  < hello>

the output will be as follows:

< hello>

In FORTRAN versions 5.0 and 5.1, command-line arguments can be accessed using the NARGS function and the GETARG procedure described on page 271 of the "Microsoft FORTRAN Reference" manual for version 5.0 or 5.1.

The PSPTST Program

c The INTERFACE statement is used to pass the addresses of the start
c of the command line and the number of characters in the command line
c to the separately compiled subroutine, DMPCMD, by value, instead of
c by reference. The variables are passed by value because they are
c themselves addresses. The DMPCMD subroutine is compiled separately
c so that it will accept its arguments by reference. This results in
c the two passed addresses being properly "dereferenced."
c
      INTERFACE TO SUBROUTINE DMPCMD( II,JJ )
      INTEGER*4 II [VALUE], JJ [VALUE]

      END
c
c --------------------------------------------------------------------
      PROGRAM PSPTST
      INTEGER*4 PSP, PSPNCH, OFFSET
c --------------------------------------------------------------------
c The method used in this program will work only if the Program
c Segment Prefix precedes the main program, which it will by
c default. Since the PSP starts 16 paragraphs (256 bytes) before
c the main program, the first step is to load the variable OFFSET
c with the hex value 0010:0000, as follows:
c
      OFFSET = #00100000
c --------------------------------------------------------------------
c Use LOCFAR to find the segment:offset of the main program:
c
      PSP = LOCFAR(PSPTST)
c --------------------------------------------------------------------

c To set PSP so that it points to the start of the text of the
c command line, do the following:
c
c 1. Zero out the offset portion of the address in variable PSP.
c
c 2. Subtract 16 paragraphs from the segment:offset.
c
c 3. Add hex 81 so that PSP now points to the start of the text of the
c    command line:
c
      PSP = (PSP-MOD(PSP,#10000))-OFFSET+#81
c --------------------------------------------------------------------
c PSPNCH points to the byte (80 hex) in the PSP that contains the
c length of the command line:
c
      PSPNCH = PSP-1
c --------------------------------------------------------------------
c Call DMPCMD to list out the command line:
c
      CALL DMPCMD(PSP, PSPNCH)
      END

THE DMPCMD SUBROUTINE

Note: Compile this routine in a file separate from PSPTST.

      SUBROUTINE DMPCMD(CMDLIN, N)
      CHARACTER*80 CMDLIN
      INTEGER*1 N
c
c Write out N characters from CMDLIN (N is PSP+80 hex; CMDLIN is
c PSP+81 hex).
c
      WRITE (*,*) '<',CMDLIN(:N),'>'
      RETURN
      END