Procedure

     FRSTNP ( First non-printable character )

     INTEGER FUNCTION FRSTNP ( STRING )

Abstract

     Return the index of the first non-printable character in a
     character string. ASCII characters 32-126 are considered
     printable by this routine. (Blanks are considered printable.)

Required_Reading

     None.

Keywords

     ASCII
     CHARACTER
     SEARCH

Declarations

     IMPLICIT NONE

     CHARACTER*(*)    STRING

Brief_I/O

     VARIABLE  I/O  DESCRIPTION
     --------  ---  --------------------------------------------------
     STRING     I   Input character string.

     The function returns the index of first non-printable character in
     STRING.

Detailed_Input

     STRING   is the input character string.

Detailed_Output

     The function returns the index of the first non-printable
     character in the input string. Characters having integer codes
     outside the range 32-126 are considered to be non-printable
     characters. Blanks are considered to be printable characters. If
     the input string contains no non-printable characters, FRSTNP is
     zero.

Parameters

     None.

Exceptions

     Error free.

Files

     None.

Particulars

     This routine may be used to assist in validating strings that
     are intended to be free of non-printable characters.

     This routine treats blanks as printable characters. This choice
     prevents embedded blanks from causing false positive results in
     tests of strings for invalid characters. Note that the routine
     FRSTPC and LASTPC treat blanks as non-printable.

Examples

     The numerical results shown for this example may differ across
     platforms. The results depend on the SPICE kernels used as
     input, the compiler and supporting libraries, and the machine
     specific arithmetic implementation.

     1) Find the first non-printable character in a given string,
        considering blanks as printable characters.


        Example code begins here.


              PROGRAM FRSTNP_EX1
              IMPLICIT NONE

        C
        C     SPICELIB functions
        C
              INTEGER               FRSTNP

        C
        C     Local variables
        C
              CHARACTER*10    S

        C
        C     Add some random characters to the string, some of them
        C     non-printable.
        C
              S( 1: 1) = 'A'
              S( 2: 2) = ' '
              S( 3: 3) = CHAR ( 3 )
              S( 4: 4) = 'A'
              S( 5: 5) = 'B'
              S( 6: 6) = 'C'
              S( 7: 7) = CHAR ( 7 )
              S( 8: 8) = CHAR ( 8 )
              S( 9: 9) = CHAR ( 9 )
              S(10:10) = ' '

              WRITE (*,'(A,I2)') 'First non-printable character '
             .//                 'found at index', FRSTNP(S)

              END


        When this program was executed on a Mac/Intel/gfortran/64-bit
        platform, the output was:


        First non-printable character found at index 3

Restrictions

     None.

Literature_References

     None.

Author_and_Institution

     N.J. Bachman       (JPL)
     J. Diaz del Rio    (ODC Space)
     I.M. Underwood     (JPL)

Version

    SPICELIB Version 1.1.0, 07-APR-2021 (JDR)

        Added IMPLICIT NONE statement.

        Edited the header to comply with NAIF standard. Created
        complete code example from existing fragment.

    SPICELIB Version 1.0.0, 16-JUN-1995 (NJB) (IMU)