FUNCTION str_text_len(s)
c
c Purpose:  find the effective length of the string  s .  That is,
c   the length from the beginning until either (1) the first space character,
c   (20 hex) or tab character (09 hex),  or (2) the end of the string.
c

      IMPLICIT NONE

      INTEGER*4       str_text_len
      CHARACTER*(*)   s

      INTEGER*4 i, n
      BYTE      c
      CHARACTER*1 cc
      EQUIVALENCE (c,cc)

      n= LEN(s)

      i=1
  100 CONTINUE
        cc= s(i:i)
        IF((c .EQ. '20'X ) .OR. (c .EQ. '09'X)) GOTO 200
        i= i+1
        IF (i .LE. n) GOTO 100

  200 CONTINUE
      str_text_len= i  - 1
      RETURN
      END