Function            strclean - remove non-printable ASCII codes

  Syntax              char *strclean(char *str);

  Prototype in        stringhk.h

  Remarks             strclean removes any non-printable ASCII characters
                      from the string str. Non-printable is defined as
                      per the isprint() function. The string passed to
                      strclean is modified.

  Return value        returns str.