! This file: http://ftp.aset.psu.edu/pub/ger/fortran/hdk/Deblank.f90
!
subroutine remove_blanks(chr)
! posted by James Giles at comp.lang.fortran on 3 August 2003.
   implicit none
   character(*), intent(inout) :: chr
   integer :: i, j, istart

   istart = index(chr, " ")
   if (istart == 0) return   ! no blanks in the argument

   j = istart-1  ! just before the first blank.

   do i = istart, len(trim(chr))
      if (chr(i:i) /= " ") then
         j = j+1
         chr(j:j) = chr(i:i)
      endif
   end do

   if(j < len(chr)) chr(j+1:) = " "  ! clear the rest of the string
   return
end subroutine remove_blanks


Program DeBlank
! Simple test of subroutine remove_blanks.
Character (len=40) line
! read(*,'(A)') line
  Line = '  abcd efgh    ijkl   '
  call remove_blanks (line)
  print *, line
end Program DeBlank