1// Copyright 2009 The Go Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style
3// license that can be found in the LICENSE file.
4
5// +build darwin dragonfly freebsd linux nacl netbsd openbsd solaris windows
6
7package os
8
9import (
10	"syscall"
11)
12
13// The only signal values guaranteed to be present on all systems
14// are Interrupt (send the process an interrupt) and Kill (force
15// the process to exit).
16var (
17	Interrupt Signal = syscall.SIGINT
18	Kill      Signal = syscall.SIGKILL
19)
20
21func startProcess(name string, argv []string, attr *ProcAttr) (p *Process, err error) {
22	// If there is no SysProcAttr (ie. no Chroot or changed
23	// UID/GID), double-check existence of the directory we want
24	// to chdir into.  We can make the error clearer this way.
25	if attr != nil && attr.Sys == nil && attr.Dir != "" {
26		if _, err := Stat(attr.Dir); err != nil {
27			pe := err.(*PathError)
28			pe.Op = "chdir"
29			return nil, pe
30		}
31	}
32
33	sysattr := &syscall.ProcAttr{
34		Dir: attr.Dir,
35		Env: attr.Env,
36		Sys: attr.Sys,
37	}
38	if sysattr.Env == nil {
39		sysattr.Env = Environ()
40	}
41	for _, f := range attr.Files {
42		sysattr.Files = append(sysattr.Files, f.Fd())
43	}
44
45	pid, h, e := syscall.StartProcess(name, argv, sysattr)
46	if e != nil {
47		return nil, &PathError{"fork/exec", name, e}
48	}
49	return newProcess(pid, h), nil
50}
51
52func (p *Process) kill() error {
53	return p.Signal(Kill)
54}
55
56// ProcessState stores information about a process, as reported by Wait.
57type ProcessState struct {
58	pid    int                // The process's id.
59	status syscall.WaitStatus // System-dependent status info.
60	rusage *syscall.Rusage
61}
62
63// Pid returns the process id of the exited process.
64func (p *ProcessState) Pid() int {
65	return p.pid
66}
67
68func (p *ProcessState) exited() bool {
69	return p.status.Exited()
70}
71
72func (p *ProcessState) success() bool {
73	return p.status.ExitStatus() == 0
74}
75
76func (p *ProcessState) sys() interface{} {
77	return p.status
78}
79
80func (p *ProcessState) sysUsage() interface{} {
81	return p.rusage
82}
83
84func (p *ProcessState) String() string {
85	if p == nil {
86		return "<nil>"
87	}
88	status := p.Sys().(syscall.WaitStatus)
89	res := ""
90	switch {
91	case status.Exited():
92		res = "exit status " + itoa(status.ExitStatus())
93	case status.Signaled():
94		res = "signal: " + status.Signal().String()
95	case status.Stopped():
96		res = "stop signal: " + status.StopSignal().String()
97		if status.StopSignal() == syscall.SIGTRAP && status.TrapCause() != 0 {
98			res += " (trap " + itoa(status.TrapCause()) + ")"
99		}
100	case status.Continued():
101		res = "continued"
102	}
103	if status.CoreDump() {
104		res += " (core dumped)"
105	}
106	return res
107}
108