(*
copyright (c) 2013-2015, simon cruanes
all rights reserved.

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(** {1 High-level Functions on top of Unix}

Some useful functions built on top of Unix.

{b status: unstable}
@since 0.10 *)

type 'a or_error = [`Ok of 'a | `Error of string]
type 'a gen = unit -> 'a option

(** {2 Calling Commands} *)

val escape_str : Buffer.t -> string -> unit
(** Escape a string so it can be a shell argument.
*)

(*$T
  CCPrint.sprintf "%a" escape_str "foo" = "foo"
  CCPrint.sprintf "%a" escape_str "foo bar" = "'foo bar'"
  CCPrint.sprintf "%a" escape_str "fo'o b'ar" = "'fo'\\''o b'\\''ar'"
*)

type call_result =
  < stdout:string;
    stderr:string;
    status:Unix.process_status;
    errcode:int; (** extracted from status *)
  >

val call : ?bufsize:int ->
           ?stdin:[`Gen of string gen | `Str of string] ->
           ?env:string array ->
           ('a, Buffer.t, unit, call_result) format4 ->
           'a
(** [call cmd] wraps the result of [Unix.open_process_full cmd] into an
    object. It reads the full stdout and stderr of the subprocess before
    returning.
    @param stdin if provided, the generator or string is consumed and fed to
      the subprocess input channel, which is then closed.
    @param bufsize buffer size used to read stdout and stderr
    @param env environment to run the command in
*)

(*$T
  (call ~stdin:(`Str "abc") "cat")#stdout = "abc"
  (call "echo %a" escape_str "a'b'c")#stdout = "a'b'c\n"
  (call "echo %s" "a'b'c")#stdout = "abc\n"
*)

type line = string

type async_call_result =
  < stdout:line gen;
    stderr:line gen;
    stdin:line -> unit; (* send a line *)
    close_in:unit; (* close stdin *)
    close_err:unit;
    close_out:unit;
    close_all:unit;  (* close all 3 channels *) (** @since 0.11 *)
    wait:Unix.process_status;  (* block until the process ends *)
    wait_errcode:int; (* block until the process ends, then extract errcode *)
       (** @since 0.11 *)
  >
(** A subprocess for interactive usage (read/write channels line by line)
    @since 0.11 *)

val async_call : ?env:string array ->
                 ('a, Buffer.t, unit, async_call_result) format4 ->
                 'a
(** Spawns a subprocess, like {!call}, but the subprocess's channels are
    line generators and line sinks (for stdin).
    if [p] is [async_call "cmd"], then [p#wait] waits for the subprocess
    to die. Channels can be closed independently.
    @since 0.11 *)

(** {2 Accessors}

@since 0.11 *)

val stdout : < stdout : 'a; .. > -> 'a
val stderr : < stderr : 'a; .. > -> 'a
val status : < status : 'a; .. > -> 'a
val errcode : < errcode : 'a; .. > -> 'a

(** {2 Infix Functions} *)

module Infix : sig
  val (?|) : ('a, Buffer.t, unit, call_result) format4 -> 'a
  (** Infix version of {!call}
      @since 0.11 *)

  val (?|&) : ('a, Buffer.t, unit, async_call_result) format4 -> 'a
  (** Infix version of {!async_call}
      @since 0.11 *)
end

include module type of Infix