Procedure

     LUN2FN ( Map logical unit of open file to its name. )

     SUBROUTINE LUN2FN ( LUNIT, FILNAM )

Abstract

     Map the logical unit of an open file to its associated filename.

Required_Reading

     None.

Keywords

     FILES

Declarations

     IMPLICIT NONE

     INTEGER          LUNIT
     CHARACTER*(*)    FILNAM

Brief_I/O

     VARIABLE  I/O  DESCRIPTION
     --------  ---  --------------------------------------------------
     LUNIT      I   A logical unit to be mapped to a filename.
     FILNAM     O   Name of the file associated with LUNIT.

Detailed_Input

     LUNIT    is the Fortran logical unit that is to be mapped to the
              filename with which it is associated. The file must be
              open for this routine to work properly.

Detailed_Output

     FILNAM   is the filename that is associated with the Fortran
              logical unit LUNIT.

Parameters

     None.

Exceptions

     1)  If the logical unit is not positive, the error
         SPICE(INVALIDARGUMENT) is signaled.

     2)  If an error occurs during the execution of the Fortran INQUIRE
         statement, the error SPICE(INQUIREFAILED) is signaled.

     3)  If the logical unit is not attached to an open file, the
         error SPICE(FILENOTOPEN) is signaled.

     4)  In the event of an error the contents of the variable FILNAM
         are not defined and should not be used.

Files

     None.

Particulars

     Uses the Fortran INQUIRE statement to determine the filename that
     is associated with the Fortran logical unit LUNIT.

Examples

     The following code fragment illustrates the use of LUN2FN.

     C
     C      Convert the logical unit to its filename and display it.
     C
            CALL LUN2FN ( UNIT1, FNAME1 )
            WRITE (*,*) 'The filename is: ', FNAME1

Restrictions

     None.

Literature_References

     None.

Author_and_Institution

     J. Diaz del Rio    (ODC Space)
     K.R. Gehringer     (JPL)

Version

    SPICELIB Version 1.1.0, 12-AUG-2021 (JDR)

        Added IMPLICIT NONE statement.

        Edited the header to comply with NAIF standard.

    SPICELIB Version 1.0.0, 16-AUG-1994 (KRG)