Procedure

     SPCT2B ( SPK and CK, text to binary )

     SUBROUTINE SPCT2B ( UNIT, BINARY )

Abstract

     Reconstruct a binary SPK or CK file including comments
     from a text file opened by the calling program.

Required_Reading

     SPC

Keywords

     FILES

Declarations

     IMPLICIT NONE

     INTEGER               UNIT
     CHARACTER*(*)         BINARY

Brief_I/O

     VARIABLE  I/O  DESCRIPTION
     --------  ---  --------------------------------------------------
     UNIT       I   Logical unit connected to the text format file.
     BINARY     I   Name of a binary SPK or CK file to be created.

Detailed_Input

     UNIT     is the logical unit connected to an existing text
              format SPK or CK file that may contain comments in
              the appropriate SPC format, as written by SPCB2A or
              SPCB2T. This file must be opened for read access
              using the routine TXTOPR.

              This file may contain text that precedes and
              follows the SPK or CK data and comments, however,
              when calling this routine, the file pointer must be
              in a position in the file such that the next line
              returned by a READ statement is

                   ''NAIF/DAF''

              which marks the beginning of the data.

     BINARY   is the name of a binary SPK or CK file to be created.
              The binary file contains the same data and comments
              as the text file, but in the binary format required
              for use with the SPICELIB reader subroutines.

Detailed_Output

     None.

Parameters

     None.

Exceptions

     1)  If there is a problem opening or writing to the binary file,
         an error is signaled by a routine in the call tree of this
         routine.

     2)  If there is a problem reading from the text file, the
         error SPICE(FILEREADFAILED) is signaled.

     3)  If there is a problem opening a scratch file, the error
         SPICE(FILEOPENERROR) is signaled.

     4)  If there is a problem writing to the scratch file, the
         error SPICE(FILEWRITEFAILED) is signaled.

Files

     See arguments UNIT and BINARY above.

     This routine uses a Fortran scratch file to temporarily store the
     lines of comments if there are any.

Particulars

     The SPICELIB SPK and CK reader subroutines read binary files.
     However, because different computing environments have different
     binary representations of numbers, you must convert SPK and CK
     files to text format when porting from one system to another.
     After converting the file to text, you can transfer it using
     a transfer protocol program like Kermit or FTP. Then, convert
     the text file back to binary format.

     The following is a list of the SPICELIB routines that convert
     SPK and CK files between binary and text format:

        SPCA2B    converts text to binary. It opens the text file,
                  creates a new binary file, and closes both files.

        SPCB2A    converts binary to text. It opens the binary file,
                  creates a new text file, and closes both files.

        SPCT2B    converts text to binary. It creates a new binary
                  file and closes it. The text file is open on
                  entrance and exit.

        SPCB2T    converts binary to text. It opens the binary
                  file and closes it. The text file is open on
                  entrance and exit

     See the SPC required reading for more information
     about SPC routines and the SPK and CK file formats.

Examples

     1)  The following code fragment creates a text file containing
         text format SPK data and comments preceded and followed
         by a standard label.

         The SPICELIB routine TXTOPN opens a new text file and TXTOPR
         opens an existing text file for read access. TEXT and
         BINARY are character strings that contain the names of the
         text and binary files.

            CALL TXTOPN ( TEXT, UNIT )

            (Write header label to UNIT)

            CALL SPCB2T ( BINARY, UNIT )

            (Write trailing label to UNIT)

            CLOSE ( UNIT )


         The following code fragment reconverts the text format
         SPK data and comments back into binary format.

            CALL TXTOPR ( TEXT, UNIT )

            (Read, or just read past, header label from UNIT)

            CALL SPCT2B ( UNIT, BINARY )

            (Read trailing label from UNIT, if desired )

            CLOSE ( UNIT )


     2)  Suppose three text format SPK files have been appended
         together into one text file called THREE.TSP. The following
         code fragment converts each set of data and comments into
         its own binary file.

            CALL TXTOPR ( 'THREE.TSP', UNIT  )

            CALL SPCT2B ( UNIT, 'FIRST.BSP'  )
            CALL SPCT2B ( UNIT, 'SECOND.BSP' )
            CALL SPCT2B ( UNIT, 'THIRD.BSP'  )

            CLOSE ( UNIT )

Restrictions

     1)  This routine assumes that the data and comments in the
         text format SPK or CK file come from a binary file
         and were written by one of the routines SPCB2A or SPCB2T.
         Data and/or comments written any other way may not be
         in the correct format and, therefore, may not be handled
         properly.

     2)  Older versions of SPK and CK files did not have a comment
         area. These files, in text format, may still be converted
         to binary using SPCT2B. However, upon exit, the file pointer
         will not be in position ready to read the first line of text
         after the data. Instead, the next READ statement after
         calling SPCT2B will return the second line of text after
         the data. Therefore, example 1 may not work as desired
         if the trailing label begins on the first line after the
         data. To solve this problem, use DAFT2B instead of SPCT2B.

     3)  UNIT must be obtained via TXTOPR. Use TXTOPR to open text
         files for read access and get the logical unit. System
         dependencies regarding opening text files have been isolated
         in the routines TXTOPN and TXTOPR.

Literature_References

     None.

Author_and_Institution

     J. Diaz del Rio    (ODC Space)
     J.E. McLean        (JPL)
     W.L. Taber         (JPL)

Version

    SPICELIB Version 1.1.0, 13-AUG-2021 (JDR)

        Added IMPLICIT NONE statement.

        Edited the header to comply with NAIF standard.

    SPICELIB Version 1.0.1, 10-MAR-1992 (WLT)

        Comment section for permuted index source lines was added
        following the header.

    SPICELIB Version 1.0.0, 05-APR-1991 (JEM)