--          This file is part of SmallEiffel The GNU Eiffel Compiler.
--          Copyright (C) 1994-98 LORIA - UHP - CRIN - INRIA - FRANCE
--            Dominique COLNET and Suzanne COLLIN - colnet@loria.fr
--                       http://SmallEiffel.loria.fr
-- SmallEiffel is  free  software;  you can  redistribute it and/or modify it
-- under the terms of the GNU General Public License as published by the Free
-- Software  Foundation;  either  version  2, or (at your option)  any  later
-- version. SmallEiffel is distributed in the hope that it will be useful,but
-- WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
-- or  FITNESS FOR A PARTICULAR PURPOSE.   See the GNU General Public License
-- for  more  details.  You  should  have  received a copy of the GNU General
-- Public  License  along  with  SmallEiffel;  see the file COPYING.  If not,
-- write to the  Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-- Boston, MA 02111-1307, USA.
--
class SAME_EXECUTABLES
--
-- Check if two files given as arguments are (quite) the same
-- executables files.
-- Terminate execution with the corresponding exit status code.
--

creation make

feature {NONE}

   msg1, msg2: STD_FILE_READ;

feature

   make is
      local
         path1, path2: STRING;
      do
         if argument_count < 2 then
            io.put_string("usage: same_files <path1> <path2>%N");
            die_with_code(exit_failure_code);
         end;
         path1 := argument(1);
         path2 := argument(2);
         exists(path1);
         exists(path2);
         if same_executables(path1,path2) then
            io.put_string("Sames files.%N");
         else
            io.put_string("Files differ.%N");
            die_with_code(exit_failure_code);
         end;
      end;

feature {NONE}

   same_executables(path1,path2: STRING): BOOLEAN is
      local
         f1, f2: STD_FILE_READ;
         diff_count: INTEGER;
         stop: BOOLEAN;
      do
         from
            !!f1.connect_to(path1);
            if f1.is_connected then
               if not f1.end_of_input then
                  f1.read_character;
               end;
            end;
            !!f2.connect_to(path2);
            if f2.is_connected then
               if not f2.end_of_input then
                  f2.read_character;
               end;
            end;
            diff_count := 4;
         until
            stop
         loop
            if f1.end_of_input then
               if f2.end_of_input then
                  stop := true;
                  Result := true;
               else
                  stop := true;
                  Result := false;
               end;
            elseif f2.end_of_input then
               stop := true;
               Result := false;
            else
               if f1.last_character /= f2.last_character then
                  diff_count := diff_count - 1;
                  if diff_count = 0 then
                     stop := true;
                     Result := false;
                  end;
               end;
               f1.read_character;
               f2.read_character;
            end;
         end;
         f1.disconnect;
         f2.disconnect;
      end;

   exists(path: STRING) is
      do
         if not file_exists(path) then
            io.put_string("File : %"");
            io.put_string(path);
            io.put_string("%" not found.%N");
            die_with_code(exit_failure_code);
         end;
      end;

end -- SAME_EXECUTABLES