Procedure

     RTRIM ( Right trim )

     INTEGER FUNCTION RTRIM ( STRING )

Abstract

     Return the maximum of 1 and the location of the last non-blank
     character in the string.

Required_Reading

     None.

Keywords

     CHARACTER
     STRING

Declarations

     IMPLICIT NONE

     CHARACTER*(*)         STRING

Brief_I/O

     VARIABLE  I/O  DESCRIPTION
     --------  ---  --------------------------------------------------

     STRING     I   String to be trimmed.

     The function returns the maximum of 1 and the location of the
     last non-blank character in STRING.

Detailed_Input

     STRING   is a string to be trimmed: the location of the
              last non-blank character is desired.

Detailed_Output

     The function returns the maximum of 1 and the location of the
     last non-blank character in STRING.

     In particular, when STRING is blank, the function returns the
     value 1.

Parameters

     None.

Exceptions

     Error free.

Files

     None.

Particulars

     When writing a character string to a file, we usually are content
     to omit the trailing blanks. We'd like to use LASTNB as an upper
     substring bound, but we have to handle the case where LASTNB
     returns 0, so we write:


        WRITE ( UNIT, '(A)' ),  STRING ( : MAX (1, LASTNB (STRING)) )


     This can be simplified using RTRIM:


        WRITE ( UNIT, '(A)' ),  STRING ( : RTRIM (STRING) )  )


     This routine has a counterpart, LTRIM, which finds the maximum of
     1 and the position of the first non-blank character of a string.

Examples

     1)  Write the non-blank portion of each element of a character
         cell to file SPUD.DAT:

            DO I = 1,  CARDC (CELL)

               CALL WRLINE ( 'SPUD.DAT',
           .                  CELL(I) ( LTRIM (CELL) : RTRIM (CELL) ) )

            END DO

         When CELL(I) is blank, the string ' ' will be written.

Restrictions

     None.

Literature_References

     None.

Author_and_Institution

     N.J. Bachman       (JPL)
     J. Diaz del Rio    (ODC Space)
     W.L. Taber         (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 1.0.1, 10-MAR-1992 (WLT)

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

    SPICELIB Version 1.0.0, 02-MAY-1990 (NJB)