XmStringLength — A compound string function that obtains the length of a compound string "XmStringLength"

       This  function  is  obsolete  and  exists  for  compatibility  with  previous releases. It is replaced by
       XmStringByteStreamLength.  XmStringLength obtains the length of a compound string. It returns the  number
       of  bytes  in  s1 including all tags, direction indicators, and separators. If the compound string has an
       invalid structure, 0 (zero) is returned.

       s1        Specifies the compound string

XmStringLength — A compound string function that obtains the length of a compound string "XmStringLength"
       "compound string functions" "XmStringLength"

XmStringByteStreamLength(3) and XmStringCreate(3).

                                                                                               XmStringLength(3)

       Returns the length of the compound string.

       #include <Xm/Xm.h>
       intXmStringLength(
       XmStrings1);