Procedure

     INTSTR  ( Integer to character string )

     SUBROUTINE INTSTR ( NUMBER, STRING )

Abstract

     Convert an integer to an equivalent character string.

Required_Reading

     None.

Keywords

     ALPHANUMERIC
     CONVERSION

Declarations

     IMPLICIT NONE

     INTEGER               NUMBER
     CHARACTER*(*)         STRING

Brief_I/O

     VARIABLE  I/O  DESCRIPTION
     --------  ---  --------------------------------------------------
     NUMBER     I   Integer to be converted.
     STRING     O   Equivalent character string, left justified.

Detailed_Input

     NUMBER   is the integer to be converted into a character string.

Detailed_Output

     STRING   is the character string representing the integer NUMBER.

Parameters

     None.

Exceptions

     Error free.

     1)  If the output character string is not large enough to
         contain the entire character string produced, the output
         character string will be truncated on the right.

Files

     None.

Particulars

     This routine will convert a signed integer into an equivalent
     decimal character string representation. The decimal digits of
     the integer NUMBER are found by repeated applications of
     "modulus" and division operations.

Examples

     The following argument values illustrate the use of INTSTR.

         NUMBER        STRING
         ------------  ---------------------
          1            '-1'
         -1            '-1'
          223          '223'
         -32           '-32'
          0            '0'
          2147483647   '2147483647'   ( Maximum 32 bit integer )
         -2147483647   '-2147483647'  ( Minimum 32 bit integer + 1 )
         -2147483647   '-2147483648'  ( Minimum 32 bit integer )

Restrictions

     1)  This routine assumes that all signed integers will fit into a
         character string with LINLEN or fewer digits. See the
         parameter LINLEN below for the current value.

Literature_References

     None.

Author_and_Institution

     J. Diaz del Rio    (ODC Space)
     K.R. Gehringer     (JPL)
     H.A. Neilan        (JPL)
     M.J. Spencer       (JPL)
     W.L. Taber         (JPL)
     I.M. Underwood     (JPL)

Version

    SPICELIB Version 2.2.0, 12-AUG-2021 (JDR)

        Added IMPLICIT NONE statement.

        Edited the header to comply with NAIF standard.

    SPICELIB Version 2.1.0, 11-MAY-1993 (HAN) (MJS)

        DATA statement came before the SAVE statement. This is
        a violation of the ANSI Standard. It is now the other way
        around.

    SPICELIB Version 2.0.0, 14-OCT-1992 (KRG)

        The routine was rewritten to fix a bug concerning the minimum
        representable integer.

        This routine used to negate a negative number before it began
        generating its digits. This was a bad thing to do, because on
        many machines the minimum representable integer and the
        maximum representable integer have the following relationship:

           ABS( minimum integer ) = 1 + ABS( maximum integer ).

        Changing the sign of a negative number before converting it
        to a character string would cause a program to crash if it
        were attempting to convert the minimum representable integer
        into a character string.

    SPICELIB Version 1.0.2, 10-MAR-1992 (WLT)

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

    SPICELIB Version 1.0.1, 07-DEC-1990 (WLT)

        References to the old name INT2CH were removed and
        an exception added to that section.

    SPICELIB Version 1.0.0, 31-JAN-1990 (IMU) (WLT)