Is there an equivalent of 'which' on the W

Question

As I sometimes have path problems, where one of my own cmd scripts is hidden (shadowed) by another program (earlier on the path), I would like to be able to find the full path to a program on the Windows command line, given just its name.

Is there an equivalent to the UNIX command 'which'?

On UNIX, which command prints the full path of the given command to easily find and repair these shadowing problems.

Answer 1

If you can find a free Pascal compiler, you can compile this. At least it works and shows the algorithm necessary.

program Whence (input, output);
  Uses Dos, my_funk;
  Const program_version = '1.00';
        program_date    = '17 March 1994';
  VAR   path_str          : string;
        command_name      : NameStr;
        command_extension : ExtStr;
        command_directory : DirStr;
        search_dir        : DirStr;
        result            : DirStr;


  procedure Check_for (file_name : string);
    { Check existence of the passed parameter. If exists, then state so   }
    { and exit.                                                           }
  begin
    if Fsearch(file_name, '') <> '' then
    begin
      WriteLn('DOS command = ', Fexpand(file_name));
      Halt(0);    { structured ? whaddayamean structured ? }
    end;
  end;

  function Get_next_dir : DirStr;
    { Returns the next directory from the path variable, truncating the   }
    { variable every time. Implicit input (but not passed as parameter)   }
    { is, therefore, path_str                                             }
    var  semic_pos : Byte;

  begin
      semic_pos := Pos(';', path_str);
      if (semic_pos = 0) then
      begin
        Get_next_dir := '';
        Exit;
      end;

      result := Copy(Path_str, 1, (semic_pos - 1));  { return result   }
      { Hmm! although *I* never reference a Root drive (my directory tree) }
      { is 1/2 way structured), some network logon software which I run    }
      { does (it adds Z:\ to the path). This means that I have to allow    }
      { path entries with & without a terminating backslash. I'll delete   }
      { anysuch here since I always add one in the main program below.     }
      if (Copy(result, (Length(result)), 1) = '\') then
         Delete(result, Length(result), 1);

      path_str := Copy(path_str,(semic_pos + 1),
                       (length(path_str) - semic_pos));
      Get_next_dir := result;
  end;  { Of function get_next_dir }

begin
  { The following is a kludge which makes the function Get_next_dir easier  }
  { to implement. By appending a semi-colon to the end of the path         }
  { Get_next_dir doesn't need to handle the special case of the last entry }
  { which normally doesn't have a semic afterwards. It may be a kludge,    }
  { but it's a documented kludge (you might even call it a refinement).    }
  path_str := GetEnv('Path') + ';';

  if (paramCount = 0) then
  begin
    WriteLn('Whence: V', program_version, ' from ', program_date);
    Writeln;
    WriteLn('Usage: WHENCE command[.extension]');
    WriteLn;
    WriteLn('Whence is a ''find file''type utility witha difference');
    Writeln('There are are already more than enough of those :-)');
    Write  ('Use Whence when you''re not sure where a command which you ');
    WriteLn('want to invoke');
    WriteLn('actually resides.');
    Write  ('If you intend to invoke the command with an extension e.g ');
    Writeln('"my_cmd.exe param"');
    Write  ('then invoke Whence with the same extension e.g ');
    WriteLn('"Whence my_cmd.exe"');
    Write  ('otherwise a simple "Whence my_cmd" will suffice; Whence will ');
    Write  ('then search the current directory and each directory in the ');
    Write  ('for My_cmd.com, then My_cmd.exe and lastly for my_cmd.bat, ');
    Write  ('just as DOS does');
    Halt(0);
  end;

  Fsplit(paramStr(1), command_directory, command_name, command_extension);
  if (command_directory <> '') then
  begin
WriteLn('directory detected *', command_directory, '*');
    Halt(0);
  end;

  if (command_extension <> '') then
  begin
    path_str := Fsearch(paramstr(1), '');    { Current directory }
    if   (path_str <> '') then WriteLn('Dos command = "', Fexpand(path_str), '"')
    else
    begin
      path_str := Fsearch(paramstr(1), GetEnv('path'));
      if (path_str <> '') then WriteLn('Dos command = "', Fexpand(path_str), '"')
                          else Writeln('command not found in path.');
    end;
  end
  else
  begin
    { O.K, the way it works, DOS looks for a command firstly in the current  }
    { directory, then in each directory in the Path. If no extension is      }
    { given and several commands of the same name exist, then .COM has       }
    { priority over .EXE, has priority over .BAT                             }

    Check_for(paramstr(1) + '.com');     { won't return if file is found }
    Check_for(paramstr(1) + '.exe');
    Check_for(paramstr(1) + '.bat');

    { Not in current directory, search through path ... }

    search_dir := Get_next_dir;

    while (search_dir <> '') do
    begin
       Check_for(search_dir + '\' + paramstr(1) + '.com');
       Check_for(search_dir + '\' + paramstr(1) + '.exe');
       Check_for(search_dir + '\' + paramstr(1) + '.bat');
       search_dir := Get_next_dir;
    end;

    WriteLn('DOS command not found: ', paramstr(1));
  end;
end.

Answer 2

I am using GOW (GNU on Windows) which is a light version of Cygwin. You can grab it from GitHub here.

GOW (GNU on Windows) is the lightweight alternative to Cygwin. It uses a convenient Windows installer that installs about 130 extremely useful open source UNIX applications compiled as native win32 binaries. It is designed to be as small as possible, about 10 MB, as opposed to Cygwin which can run well over 100 MB depending upon options. - About Description(Brent R. Matzelle)

A screenshot of a list of commands included in GOW:

Answer 3

The GnuWin32 tools have which, along with a whole slew of other Unix tools.

Answer 4

Windows Server 2003 and later (i.e. anything after Windows XP 32 bit) provide the where.exe program which does some of what which does, though it matches all types of files, not just executable commands. (It does not match built-in shell commands like cd.) It will even accept wildcards, so where nt* finds all files in your %PATH% and current directory whose names start with nt.

Try where /? for help.

Note that Windows PowerShell defines where as an alias for the Where-Object cmdlet, so if you want where.exe, you need to type the full name instead of omitting the .exe extension.