1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
|
// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package os
import (
"runtime"
"syscall"
)
// StartProcess starts a new process with the program, arguments and attributes
// specified by name, argv and attr.
func StartProcess(name string, argv []string, attr *ProcAttr) (p *Process, err Error) {
sysattr := &syscall.ProcAttr{
Dir: attr.Dir,
Env: attr.Env,
}
// Create array of integer (system) fds.
intfd := make([]int, len(attr.Files))
for i, f := range attr.Files {
if f == nil {
intfd[i] = -1
} else {
intfd[i] = f.Fd()
}
}
sysattr.Files = intfd
pid, h, e := syscall.StartProcess(name, argv, sysattr)
if iserror(e) {
return nil, &PathError{"fork/exec", name, e}
}
return newProcess(pid, h), nil
}
// Exec replaces the current process with an execution of the
// named binary, with arguments argv and environment envv.
// If successful, Exec never returns. If it fails, it returns an Error.
// ForkExec is almost always a better way to execute a program.
func Exec(name string, argv []string, envv []string) Error {
e := syscall.Exec(name, argv, envv)
if iserror(e) {
return &PathError{"exec", name, e}
}
return nil
}
// Waitmsg stores the information about an exited process as reported by Wait.
type Waitmsg syscall.Waitmsg
// Wait waits for the Process to exit or stop, and then returns a
// Waitmsg describing its status and an Error, if any. The options
// (WNOHANG etc.) affect the behavior of the Wait call.
func (p *Process) Wait(options int) (w *Waitmsg, err Error) {
var waitmsg syscall.Waitmsg
if p.Pid == -1 {
return nil, EINVAL
}
for true {
err = syscall.Await(&waitmsg)
if iserror(err) {
return nil, NewSyscallError("wait", err)
}
if waitmsg.Pid == p.Pid {
break
}
}
return (*Waitmsg)(&waitmsg), nil
}
// Wait waits for process pid to exit or stop, and then returns a
// Waitmsg describing its status and an Error, if any. The options
// (WNOHANG etc.) affect the behavior of the Wait call.
// Wait is equivalent to calling FindProcess and then Wait
// and Release on the result.
func Wait(pid int, options int) (w *Waitmsg, err Error) {
p, e := FindProcess(pid)
if e != nil {
return nil, e
}
defer p.Release()
return p.Wait(options)
}
// Release releases any resources associated with the Process.
func (p *Process) Release() Error {
// NOOP for Plan 9.
p.Pid = -1
// no need for a finalizer anymore
runtime.SetFinalizer(p, nil)
return nil
}
// FindProcess looks for a running process by its pid.
// The Process it returns can be used to obtain information
// about the underlying operating system process.
func FindProcess(pid int) (p *Process, err Error) {
// NOOP for Plan 9.
return newProcess(pid, 0), nil
}
func (w Waitmsg) String() string {
return "exit status: " + w.Msg
}
|
