C************************************************************************
C*
C*  COPYRIGHT (c) 1981,1983,1984,1987,1988
C*  Westinghouse Electric Corporation
C*
C*  THIS SOFTWARE IS FURNISHED WITHOUT LICENSE AND MAY BE USED AND
C*  COPIED ONLY WITH THE INCLUSION OF THE ABOVE COPYRIGHT NOTICE.
C*
C*  THE INFORMATION IN THIS SOFTWARE IS SUBJECT TO CHANGE WITHOUT NOTICE
C*  AND SHOULD NOT BE CONSTRUED AS A COMMITMENT BY WESTINGHOUSE.
C*
C*  WESTINGHOUSE ASSUMES NO RESPONSIBILITY FOR THE USE OR RELIABILITY
C*  OF THIS SOFTWARE.
C*
C****************************************************************************
C	GETCH.FOR
C
C************************************************************************
C
C	GETCH returns the next character from the input stream.
C
C		Arguments
C	    Name	Type	I/O	     Meaning
C	---------------------------------------------------
C	   ch		char	 O	Next char from input
C
C************************************************************************
C
      subroutine  getch (ch)

      implicit integer (a-z)

      parameter INPUT_CHAN = 5
      parameter IMAX = 80
      parameter STACK_MAX = 3

      character ch*(*), buffer*(IMAX), stack(STACK_MAX)
      character EOL /13/
      character EOF /26/
      character chold /' '/
      integer icol /IMAX/
      integer ichan /INPUT_CHAN/
      integer pntr /0/
      logical e_flag, echo_flag /.FALSE./
      common /getchc/ EOL, EOF, chold
      common /getchi/ icol, ichan, pntr, echo_flag

 50   format (q, a)
 60   format ('+',a)

      if (pntr .gt. 0) then						! pop off push back stack
        ch = stack (pntr)
        pntr = pntr - 1
        return
      endif

      if (chold .eq. EOL) then
 100    read (ichan, 50, iostat=ios) ecol, buffer (1:max(1,ecol))	! read next line

        if (ios .lt. 0) then					! end of file
          ch = EOF
          go to 500
        endif

        icol = 0
      endif

      icol = icol + 1
      if (icol .le. ecol) then					! next character
        ch = buffer(icol:icol)
      else								! end of line
        ch = EOL
      endif
      chold = ch

 500  return
C
C************************************************************************
C
C	PUT_BACK pushes a character back into the input stream by 
C	stacking it.
C
C************************************************************************
C
      entry  put_back (ch)

      pntr = pntr + 1

      if (pntr .gt. STACK_MAX) then
        type *,'  Lexical Scanner Stack Overflow Fatal Error'
        call exit
      endif

      stack (pntr) = ch

      return
C
C************************************************************************
C
C	SET_SOURCE changes the I/O channel to read from and 
C	turns echoing on or off.
C
C************************************************************************
C
      entry  set_source (chan, e_flag)

      ichan = chan
      echo_flag = e_flag

      return
      end