Procedure

     SWAPC ( Swap character values )

     SUBROUTINE SWAPC ( A, B )

Abstract

     Swap the contents of two character strings.

Required_Reading

     None.

Keywords

     UTILITY

Declarations

     IMPLICIT NONE

     CHARACTER*(*)    A
     CHARACTER*(*)    B

Brief_I/O

     VARIABLE  I/O  DESCRIPTION
     --------  ---  --------------------------------------------------
     A         I-O  First string.
     B         I-O  Second string.

Detailed_Input

     A,
     B        are two character strings, the contents of which
              are to be swapped (exchanged).

Detailed_Output

     A,
     B        are the same two character strings, after their
              contents have been exchanged.

Parameters

     None.

Exceptions

     Error free.

Files

     None.

Particulars

     This is just shorthand notation for the code fragment

           TEMP = A
           A    = B
           B    = TEMP

     The characters in the string are swapped one at a time, so
     no intermediate string (TEMP) is needed. This means that the
     strings may be of any length.

Examples

     Let
           A = 11.D0
           B = 22.D0

     Then after calling SWAPD (A,B),

           A = 22.D0
           B = 11.D0

Restrictions

     None.

Literature_References

     None.

Author_and_Institution

     J. Diaz del Rio    (ODC Space)
     W.L. Taber         (JPL)
     I.M. Underwood     (JPL)

Version

    SPICELIB Version 1.1.0, 18-MAR-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, 31-JAN-1990 (IMU)