c     Copyright (C) 2008-2014 Vincent Eymet
c
c     KDISTRIBUTION is free software; you can redistribute it and/or modify
c     it under the terms of the GNU General Public License as published by
c     the Free Software Foundation; either version 3, or (at your option)
c     any later version.

c     KDISTRIBUTION is distributed in the hope that it will be useful,
c     but WITHOUT ANY WARRANTY; without even the implied warranty of
c     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
c     GNU General Public License for more details.

c     You should have received a copy of the GNU General Public License
c     along with KDISTRIBUTION; if not, see <http://www.gnu.org/licenses/>
c
      subroutine get_nlines(kfile,pindex,nl)
      implicit none
      include 'max.inc'
c     
c     Purpose: to get the number of lines in the provided file
c
c     Inputs:
c       + kfile: file whose number of lines has to be retrieved
c       + pindex: index of the process that executes this routine
c
c     Outputs:
c       + nl: number of lines in the "kfile" file; a value of zero indicates
c         the file does not exist
c
      integer nl,pindex,ios
      character*(Nchar_mx) kfile,command,lfile
      character*3 ich
c     label
      integer strlen
      character*(Nchar_mx) label
      label='subroutine get_nlines'

c     Number of lines in the specified data file
      call num2str3(pindex,ich)
c      call idx2str(pindex,ich)
      lfile='./nlines_'//ich(1:strlen(ich))
      command="wc -l < "//kfile(1:strlen(kfile))//" > "//
     &     lfile(1:strlen(lfile))
c     Debug
c      write(*,*) 'This is:',label(1:strlen(label))
c      write(*,*) 'command='
c      write(*,*) command(1:strlen(command))
c     Debug
      call exec(command)

      open(10,file=lfile(1:strlen(lfile)),status='old',iostat=ios)
      if (ios.ne.0) then        ! file not found
         write(*,*) 'Error from routine ',label(1:strlen(label)),' :'
         write(*,*) 'File not found:'
         write(*,*) lfile(1:strlen(lfile))
         stop
      endif
      read(10,*) nl
      close(10)

      return
      end