Procedure

     DAFHOF ( DAF, handles of open files )

     ENTRY DAFHOF ( FHSET )

Abstract

     Return a SPICE set containing the handles of all currently
     open DAFS.

Required_Reading

     DAF
     SETS

Keywords

     DAF
     FILES

Declarations

    INTEGER               LBCELL
    PARAMETER           ( LBCELL = -5 )

    INTEGER               FHSET ( LBCELL : * )

Brief_I/O

     VARIABLE  I/O  DESCRIPTION
     --------  ---  --------------------------------------------------
     FHSET      O   A set containing handles of currently open DAFS.

Detailed_Input

     None.

Detailed_Output

     FHSET    is a SPICE set containing the file handles of
              all currently open DAFs.

Parameters

     None.

Exceptions

     1)  If the set FHSET is not initialized, an error is signaled by a
         routine in the call tree of this routine.

     2)  If the set FHSET is too small to accommodate the set of
         handles to be returned, an error is signaled by a routine in
         the call tree of this routine.

Files

     None.

Particulars

     This routine allows subroutines to test file handles for
     validity before performing operations on them, such as
     finding the name of the file designated by a handle. Many
     DAF operations on handles cause errors to be signaled if
     the handles are invalid.

Examples

     1)  Find out how may DAFs are open for writing.

            C
            C    Find out which DAFs are open.
            C
                 CALL DAFHOF  ( FHSET )

            C
            C    Count the ones open for writing. These have
            C    negative file handles.
            C
                 COUNT = 0

                 DO I = 1, CARDC(FHSET)

                    IF ( FHSET(I) .LT. 0 ) THEN
                       COUNT = COUNT + 1
                    END IF

                 END DO

Restrictions

     None.

Literature_References

     None.

Author_and_Institution

     N.J. Bachman       (JPL)
     J. Diaz del Rio    (ODC Space)
     W.L. Taber         (JPL)
     F.S. Turner        (JPL)
     E.D. Wright        (JPL)

Version

    SPICELIB Version 8.0.2, 25-NOV-2021 (JDR)

        Edited the header to comply with NAIF standard.

    SPICELIB Version 8.0.1, 10-OCT-2012 (EDW)

        Corrected ordering of header section.

    SPICELIB Version 8.0.0, 13-NOV-2001 (FST)

        This routine was updated to utilize the new handle manager
        software to manage binary file formats and consolidated
        I/O code.

    SPICELIB Version 7.0.4, 08-OCT-1999 (WLT)

        The environment lines were expanded so that the supported
        environments are now explicitly given. New
        environments are WIN-NT

    SPICELIB Version 7.0.3, 16-SEP-1999 (NJB)

        CSPICE environments were added. Some typos were corrected.

    SPICELIB Version 7.0.2, 28-JUL-1999 (WLT)

        The environment lines were expanded so that the supported
        environments are now explicitly given. New
        environments are PC-DIGITAL, SGI-O32 and SGI-N32.

    SPICELIB Version 7.0.1, 17-MAR-1999 (WLT)

        The environment lines were expanded so that the supported
        environments are now explicitly given. Previously,
        environments such as SUN-SUNOS and SUN-SOLARIS were implied
        by the environment label SUN.

    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, 03-SEP-1991 (NJB) (WLT)