C+
C NAME:
C	iwhitespace
C PURPOSE:
C	Converts tabs and multiple spaces to single spaces
C CATEGORY:
C	String manipulation
C CALLING SEQUENCE:
	function  iwhitespace(cStr)
C INPUTS:
C	cStr		character*(*)	string to be processed
C OUTPUTS:
C	cStr		character*(*)	modified string
C	iwhitespace	integer		length non-trivial part of output string
C SEE ALSO:
C	uppercase, lowercase, itrim, icompress, bCompareStr
C RESTRICTIONS:
C	The string is only tested for space, tab and null
C PROCEDURE:
C	Each character in the string is converted separately.
C MODIFICATION HISTORY:
C	JAN-1992, Paul Hick (UCSD); check for NULL added (some system procedures
C	    pad strings with NULs instead of blanks)
C-
	    character	cStr*(*)

	integer		NUL	/ 0/
	integer		TAB	/ 9/
	integer		SP	/32/

	logical		bNoChar
	logical		bSpace

	bNoChar(I) = cStr(I:I) .eq. char(SP) .or. cStr(I:I) .eq. char(NUL) .or. cStr(I:I) .eq. char(TAB)

	bSpace = .FALSE.
	L = len(cStr)
	J = 1
	do I=1,L
	    if (.not. bNoChar(I)) then
		cStr(J:J) = cStr(I:I)	! Copy valid chars
		J = J+1
		bSpace = .TRUE.
	    else if (bNoChar(I) .and. bSpace) then
		cStr(J:J) = char(SP)
		J = J+1
		bSpace = .FALSE.
	    end if
	end do

	if (J .le. L) cStr(J:L) = ' '
	J = J-1
	if (cStr(J:J) .eq. char(SP)) J = J-1

	iwhitespace = J

	return
	end