Note:

You are viewing a development version of the library. Goto the latest version.

let which ?(path) fln =
  let real_path =
    match path with
      | None ->
          path_of_string 
            (try
               Sys.getenv "PATH"
             with Not_found ->
               "")
      | Some x ->
        x
  in

  let exec_test = 
    test (And(Is_exec,Is_file))
  in

  let which_path =
    match Sys.os_type with
      | "Win32" ->
          (
            let real_ext =
              List.map 
                (fun dot_ext ->
                   (* Remove leading "." if it exists *)
                   if (String.length dot_ext) >= 1 && dot_ext.[0] = '.' then
                     String.sub dot_ext 1 ((String.length dot_ext) - 1)
                   else
                     dot_ext)
                (* Extract possible extension from PATHEXT *)
                (path_of_string 
                   (try
                      Sys.getenv "PATHEXT"
                    with Not_found ->
                      ""))
            in

            let to_filename dirname ext =
              add_extension (concat dirname fln) ext
            in

            let ctst dirname ext = 
              exec_test (to_filename dirname ext)
            in

              List.fold_left
                (fun found dirname ->
                   if found = None then 
                     (
                       try 
                         let ext =
                           List.find (ctst dirname) real_ext
                         in
                           Some (to_filename dirname ext)
                       with Not_found -> 
                         None
                     )
                   else
                     found)
                None
                real_path
          )
      | _ ->
          (
            let to_filename dirname =
              concat dirname fln
            in

            try
              Some 
                (to_filename 
                   (List.find 
                      (fun dirname -> 
                         exec_test (to_filename dirname)) real_path))
            with Not_found ->
              None
          )
  in
    match which_path with 
      | Some fn -> fn
      | None -> raise Not_found