c
      program rdascii
c
c Read ascii data file generated by tgcmproc:
c
      character*80 fname
      character*80 hdr(4),labx,laby
      character*1 ans
      dimension xx(100),yy(100),f(100,100)
      data lurd/9/
c
      do 200 iii=1,1000
      write(6,"(' ')")
      write(6,"('Enter file name (zzz to stop): ',$)")
      read(5,*) fname
      if (fname(1:3).eq.'zzz') stop 'bye'
      open(lurd,file=fname,status='OLD',err=901)
      write(6,"('Ask about printing for every frame in the',
     +  ' file? (y/n): ',$)")
      read(5,*) ans
      iprompt = 0
      if (ans.eq.'y') iprompt = 1
      nfr = 0
c
c Read data from each frame:
c
 100  continue
      do i=1,4
        read(lurd,"(a)",end=900) hdr(i)
      enddo
      read(lurd,"(a)") labx
      read(labx,"(3x,i4)") nx
      if (nx.gt.1) read(lurd,"(6e13.5)") (xx(i),i=1,nx)
      read(lurd,"(a)") laby
      read(laby,"(3x,i4)") ny
      if (ny.gt.1) read(lurd,"(6e13.5)") (yy(i),i=1,ny)
c
      if (nx.gt.1.and.ny.gt.1) then
        read(lurd,"(6e13.5)") ((f(i,ii),i=1,nx),ii=1,ny)
      elseif (nx.eq.1.and.ny.gt.1) then
        read(lurd,"(6e13.5)") (f(1,i),i=1,ny)
      elseif (ny.eq.1.and.nx.gt.1) then
        read(lurd,"(6e13.5)") (f(i,1),i=1,nx)
      endif
      nfr = nfr+1
c
c Conditionally echo to stdout:
c
      write(6,"(' ')")
c     write(6,"(a)") histvol(1:lenstr(histvol))
c     write(6,"(a)") field(1:lenstr(field))
c     write(6,"('Frame ',i4)") iframe
c     write(6,"(a)") lab(1:lenstr(lab))
      do i=1,4
        write(6,"(a)") hdr(i)
      enddo
      write(6,"(a)") labx(1:lenstr(labx))
      if (nx.gt.1) then
        if (nfr.eq.1.or.iprompt.gt.0) then
          write(6,"('Print x-axis values? (y/n/q): ',$)")
          read(5,*) ans
        else
          ans = 'n'
        endif
        if (ans.eq.'y') write(6,"(6e13.5)") (xx(i),i=1,nx)
        if (ans.eq.'q') goto 902
      endif
      write(6,"(a)") laby(1:lenstr(laby))
      if (ny.gt.1) then
        if (nfr.eq.1.or.iprompt.gt.0) then
          write(6,"('Print y-axis values? (y/n/q): ',$)")
          read(5,*) ans
        else
          ans = 'n'
        endif
        if (ans.eq.'y') write(6,"(6e13.5)") (yy(i),i=1,ny)
        if (ans.eq.'q') goto 902
      endif
      if (nfr.eq.1.or.iprompt.gt.0) then
        write(6,"('Print data values? (y/n/q): ',$)")
        read(5,*) ans
      else
        ans = 'n'
      endif
      if (ans.eq.'y') then
        if (nx.gt.1.and.ny.gt.1) then
          write(6,"(6e13.5)") ((f(i,ii),i=1,nx),ii=1,ny)
        elseif (nx.eq.1.and.ny.gt.1) then
          write(6,"(6e13.5)") (f(1,i),i=1,ny)
        elseif (ny.eq.1.and.nx.gt.1) then
          write(6,"(6e13.5)") (f(i,1),i=1,nx)
        endif
      endif
      if (ans.eq.'q') goto 902
      goto 100
c
      stop
 900  continue
      write(6,"('EOF encountered on file ',a,' (lu ',i3,')')")
     +  fname,lurd
 902  close(lurd)
      goto 200
 901  write(6,"('Error opening file ',a)") fname
 200  continue
      stop
      end
c
ccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc
c
      function lenstr(str)
      character*(*) str
c
c Return index to last non-blank char in str
c
      length = len(str)
      do i=length,1,-1
        if (str(i:i).ne.' ') then
          lenstr = i
          return
        endif
      enddo
      lenstr = 0
      return
      end
c
      subroutine clearstr(str)
c 
c Set given string to all blanks 
c 
      character*(*) str
      length = len(str)
      do i=1,length
        str(i:i) = ' '
      enddo
      return
      end