libgo/go/os/exec_posix.go

   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 aix darwin dragonfly freebsd linux nacl netbsd openbsd solaris windows
   6
   7 package os
   8
   9 import (
  10         "syscall"
  11 )
  12
  13 // The only signal values guaranteed to be present in the os package
  14 // on all systems are Interrupt (send the process an interrupt) and
  15 // Kill (force the process to exit). Interrupt is not implemented on
  16 // Windows; using it with os.Process.Signal will return an error.
  17 var (
  18         Interrupt Signal = syscall.SIGINT
  19         Kill      Signal = syscall.SIGKILL
  20 )
  21
  22 func startProcess(name string, argv []string, attr *ProcAttr) (p *Process, err error) {
  23         // If there is no SysProcAttr (ie. no Chroot or changed
  24         // UID/GID), double-check existence of the directory we want
  25         // to chdir into. We can make the error clearer this way.
  26         if attr != nil && attr.Sys == nil && attr.Dir != "" {
  27                 if _, err := Stat(attr.Dir); err != nil {
  28                         pe := err.(*PathError)
  29                         pe.Op = "chdir"
  30                         return nil, pe
  31                 }
  32         }
  33
  34         sysattr := &syscall.ProcAttr{
  35                 Dir: attr.Dir,
  36                 Env: attr.Env,
  37                 Sys: attr.Sys,
  38         }
  39         if sysattr.Env == nil {
  40                 sysattr.Env = Environ()
  41         }
  42         for _, f := range attr.Files {
  43                 sysattr.Files = append(sysattr.Files, f.Fd())
  44         }
  45
  46         pid, h, e := syscall.StartProcess(name, argv, sysattr)
  47         if e != nil {
  48                 return nil, &PathError{"fork/exec", name, e}
  49         }
  50         return newProcess(pid, h), nil
  51 }
  52
  53 func (p *Process) kill() error {
  54         return p.Signal(Kill)
  55 }
  56
  57 // ProcessState stores information about a process, as reported by Wait.
  58 type ProcessState struct {
  59         pid    int                // The process's id.
  60         status syscall.WaitStatus // System-dependent status info.
  61         rusage *syscall.Rusage
  62 }
  63
  64 // Pid returns the process id of the exited process.
  65 func (p *ProcessState) Pid() int {
  66         return p.pid
  67 }
  68
  69 func (p *ProcessState) exited() bool {
  70         return p.status.Exited()
  71 }
  72
  73 func (p *ProcessState) success() bool {
  74         return p.status.ExitStatus() == 0
  75 }
  76
  77 func (p *ProcessState) sys() interface{} {
  78         return p.status
  79 }
  80
  81 func (p *ProcessState) sysUsage() interface{} {
  82         return p.rusage
  83 }
  84
  85 func (p *ProcessState) String() string {
  86         if p == nil {
  87                 return "<nil>"
  88         }
  89         status := p.Sys().(syscall.WaitStatus)
  90         res := ""
  91         switch {
  92         case status.Exited():
  93                 res = "exit status " + itoa(status.ExitStatus())
  94         case status.Signaled():
  95                 res = "signal: " + status.Signal().String()
  96         case status.Stopped():
  97                 res = "stop signal: " + status.StopSignal().String()
  98                 if status.StopSignal() == syscall.SIGTRAP && status.TrapCause() != 0 {
  99                         res += " (trap " + itoa(status.TrapCause()) + ")"
 100                 }
 101         case status.Continued():
 102                 res = "continued"
 103         }
 104         if status.CoreDump() {
 105                 res += " (core dumped)"
 106         }
 107         return res
 108 }