basis-library/mlton/process.sig

   1 (* Copyright (C) 2002-2007 Henry Cejtin, Matthew Fluet, Suresh
   2  *    Jagannathan, and Stephen Weeks.
   3  *
   4  * MLton is released under a BSD-style license.
   5  * See the file MLton-LICENSE for details.
   6  *)
   7
   8 signature MLTON_PROCESS =
   9    sig
  10       type pid
  11
  12       val spawn: {args: string list, path: string} -> pid
  13       val spawne: {args: string list, env: string list, path: string} -> pid
  14       val spawnp: {file: string, args: string list} -> pid
  15
  16       (* Process handle *)
  17       type ('stdin, 'stdout, 'stderr) t
  18
  19       (* is the io 'dir input or output *)
  20       type input
  21       type output
  22
  23       (* to what use can the stdio channel be put *)
  24       type none  (* it's not connected to a pipe *)
  25       type chain (* connect one child to another *)
  26       type any   (* any use is allowed -- dangerous *)
  27
  28       exception MisuseOfForget   (* you avoided the type safety and broke it *)
  29       exception DoublyRedirected (* you tried to reuse a Param.child *)
  30
  31       structure Child:
  32         sig
  33           type ('use, 'dir) t
  34
  35           val binIn: (BinIO.instream, input) t -> BinIO.instream
  36           val binOut: (BinIO.outstream, output) t -> BinIO.outstream
  37           (* not necessarily available on all systems; may raise an exception *)
  38           val fd: (Posix.FileSys.file_desc, 'dir) t -> Posix.FileSys.file_desc
  39           (* used for situations where 'forget' was needed for arbitrary redir *)
  40           val remember: (any, 'dir) t -> ('use, 'dir) t
  41           val textIn: (TextIO.instream, input) t -> TextIO.instream
  42           val textOut: (TextIO.outstream, output) t -> TextIO.outstream
  43         end
  44
  45       structure Param:
  46         sig
  47           type ('use, 'dir) t
  48
  49           (* {child,fd} close their parameter when create is called.
  50            * therefore they may only be used once!
  51            *)
  52           val child: (chain, 'dir) Child.t -> (none, 'dir) t
  53           (* Not necessarily available on all systems; may raise an exception *)
  54           val fd: Posix.FileSys.file_desc -> (none, 'dir) t
  55           val file: string -> (none, 'dir) t
  56           (* used if you want to return two posibilities; use with care *)
  57           val forget: ('use, 'dir) t -> (any, 'dir) t
  58           val null: (none, 'dir) t
  59           val pipe: ('use, 'dir) t
  60           val self: (none, 'dir) t
  61         end
  62
  63       val create:
  64          {args: string list,
  65           env: string list option,
  66           path: string,
  67           stderr: ('stderr, output) Param.t,
  68           stdin: ('stdin, input) Param.t,
  69           stdout: ('stdout, output) Param.t}
  70          -> ('stdin, 'stdout, 'stderr) t
  71       val getStderr: ('stdin, 'stdout, 'stderr) t -> ('stderr, input) Child.t
  72       val getStdin:  ('stdin, 'stdout, 'stderr) t -> ('stdin, output) Child.t
  73       val getStdout: ('stdin, 'stdout, 'stderr) t -> ('stdout, input) Child.t
  74       val kill: ('stdin, 'stdout, 'stderr) t * Posix.Signal.signal -> unit
  75       val reap: ('stdin, 'stdout, 'stderr) t -> Posix.Process.exit_status
  76    end