Annotation of /sml/trunk/src/system/Basis/Implementation/Unix/unix.sml

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Revision 417 - (view) (download)
Original Path: sml/branches/SMLNJ/src/system/Basis/Implementation/Unix/unix.sml

1 :	monnier	416	(* unix.sml
2 :			*
3 :			* COPYRIGHT (c) 1995 AT&T Bell Laboratories.
4 :			*
5 :			*)
6 :
7 :			structure Unix : UNIX =
8 :			struct
9 :
10 :			structure P = Posix.Process
11 :			structure PE = Posix.ProcEnv
12 :			structure PF = Posix.FileSys
13 :			structure PIO = Posix.IO
14 :			structure SS = Substring
15 :
16 :			fun protect f x = let
17 :			val _ = Signals.maskSignals Signals.MASKALL
18 :			val y = (f x) handle ex =>
19 :			(Signals.unmaskSignals Signals.MASKALL; raise ex)
20 :			in
21 :			Signals.unmaskSignals Signals.MASKALL; y
22 :			end
23 :
24 :			fun fdReader (name : string, fd : PIO.file_desc) =
25 :			PosixTextPrimIO.mkReader {
26 :			initBlkMode = true,
27 :			name = name,
28 :			fd = fd
29 :			}
30 :
31 :			fun fdWriter (name, fd) =
32 :			PosixTextPrimIO.mkWriter {
33 :			appendMode = false,
34 :			initBlkMode = true,
35 :			name = name,
36 :			chunkSize=4096,
37 :			fd = fd
38 :			}
39 :
40 :			fun openOutFD (name, fd) =
41 :			TextIO.mkOutstream (
42 :			TextIO.StreamIO.mkOutstream (
43 :			fdWriter (name, fd), IO.BLOCK_BUF))
44 :
45 :			fun openInFD (name, fd) =
46 :			TextIO.mkInstream (
47 :			TextIO.StreamIO.mkInstream (
48 :			fdReader (name, fd), ""))
49 :
50 :			datatype proc = PROC of {
51 :			pid : P.pid,
52 :			ins : TextIO.instream,
53 :			outs : TextIO.outstream
54 :			}
55 :
56 :			fun executeInEnv (cmd, argv, env) = let
57 :			val p1 = PIO.pipe ()
58 :			val p2 = PIO.pipe ()
59 :			fun closep () = (
60 :			PIO.close (#outfd p1);
61 :			PIO.close (#infd p1);
62 :			PIO.close (#outfd p2);
63 :			PIO.close (#infd p2)
64 :			)
65 :			val base = SS.string(SS.taker (fn c => c <> #"/") (SS.all cmd))
66 :			fun startChild () = (case protect P.fork ()
67 :			of SOME pid => pid (* parent *)
68 :			| NONE => let
69 :			val oldin = #infd p1
70 :			val newin = Posix.FileSys.wordToFD 0w0
71 :			val oldout = #outfd p2
72 :			val newout = Posix.FileSys.wordToFD 0w1
73 :			in
74 :			PIO.close (#outfd p1);
75 :			PIO.close (#infd p2);
76 :			if (oldin = newin) then ()
77 :			else (
78 :			PIO.dup2{old = oldin, new = newin};
79 :			PIO.close oldin);
80 :			if (oldout = newout) then ()
81 :			else (
82 :			PIO.dup2{old = oldout, new = newout};
83 :			PIO.close oldout);
84 :			P.exece (cmd, base::argv, env)
85 :			end
86 :			(* end case *))
87 :			val _ = TextIO.flushOut TextIO.stdOut
88 :			val pid = (startChild ()) handle ex => (closep(); raise ex)
89 :			val ins = openInFD (base^"_exec_in", #infd p2)
90 :			val outs = openOutFD (base^"_exec_out", #outfd p1)
91 :			in
92 :			(* close the child-side fds *)
93 :			PIO.close (#outfd p2);
94 :			PIO.close (#infd p1);
95 :			(* set the fds close on exec *)
96 :			PIO.setfd (#infd p2, PIO.FD.flags [PIO.FD.cloexec]);
97 :			PIO.setfd (#outfd p1, PIO.FD.flags [PIO.FD.cloexec]);
98 :			PROC {
99 :			pid = pid,
100 :			ins = ins,
101 :			outs = outs
102 :			}
103 :			end
104 :
105 :			fun execute (cmd, argv) = executeInEnv (cmd, argv, PE.environ())
106 :
107 :			fun streamsOf (PROC{ins,outs,...}) = (ins, outs)
108 :
109 :			fun kill (PROC{pid,...},signal) = P.kill (P.K_PROC pid, signal)
110 :
111 :			fun reap (PROC{pid,ins,outs}) = let
112 :			(* protect is probably too much; typically, one
113 :			* would only mask SIGINT, SIGQUIT and SIGHUP
114 :			*)
115 :			fun waitProc () = #2(protect P.waitpid (P.W_CHILD pid,[]))
116 :			in
117 :			TextIO.closeIn ins;
118 :			TextIO.closeOut outs;
119 :			waitProc ()
120 :			end
121 :
122 :			end (* structure Unix *)
123 :

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