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 //go:build aix || darwin || dragonfly || freebsd || hurd || (js && wasm) || linux || netbsd || openbsd || solaris || windows
   6
   7 package os
   8
   9 import (
  10         "internal/itoa"
  11         "internal/syscall/execenv"
  12         "runtime"
  13         "syscall"
  14 )
  15
  16 // The only signal values guaranteed to be present in the os package on all
  17 // systems are os.Interrupt (send the process an interrupt) and os.Kill (force
  18 // the process to exit). On Windows, sending os.Interrupt to a process with
  19 // os.Process.Signal is not implemented; it will return an error instead of
  20 // sending a signal.
  21 var (
  22         Interrupt Signal = syscall.SIGINT
  23         Kill      Signal = syscall.SIGKILL
  24 )
  25
  26 func startProcess(name string, argv []string, attr *ProcAttr) (p *Process, err error) {
  27         // If there is no SysProcAttr (ie. no Chroot or changed
  28         // UID/GID), double-check existence of the directory we want
  29         // to chdir into. We can make the error clearer this way.
  30         if attr != nil && attr.Sys == nil && attr.Dir != "" {
  31                 if _, err := Stat(attr.Dir); err != nil {
  32                         pe := err.(*PathError)
  33                         pe.Op = "chdir"
  34                         return nil, pe
  35                 }
  36         }
  37
  38         sysattr := &syscall.ProcAttr{
  39                 Dir: attr.Dir,
  40                 Env: attr.Env,
  41                 Sys: attr.Sys,
  42         }
  43         if sysattr.Env == nil {
  44                 sysattr.Env, err = execenv.Default(sysattr.Sys)
  45                 if err != nil {
  46                         return nil, err
  47                 }
  48         }
  49         sysattr.Files = make([]uintptr, 0, len(attr.Files))
  50         for _, f := range attr.Files {
  51                 sysattr.Files = append(sysattr.Files, f.Fd())
  52         }
  53
  54         pid, h, e := syscall.StartProcess(name, argv, sysattr)
  55
  56         // Make sure we don't run the finalizers of attr.Files.
  57         runtime.KeepAlive(attr)
  58
  59         if e != nil {
  60                 return nil, &PathError{Op: "fork/exec", Path: name, Err: e}
  61         }
  62
  63         return newProcess(pid, h), nil
  64 }
  65
  66 func (p *Process) kill() error {
  67         return p.Signal(Kill)
  68 }
  69
  70 // ProcessState stores information about a process, as reported by Wait.
  71 type ProcessState struct {
  72         pid    int                // The process's id.
  73         status syscall.WaitStatus // System-dependent status info.
  74         rusage *syscall.Rusage
  75 }
  76
  77 // Pid returns the process id of the exited process.
  78 func (p *ProcessState) Pid() int {
  79         return p.pid
  80 }
  81
  82 func (p *ProcessState) exited() bool {
  83         return p.status.Exited()
  84 }
  85
  86 func (p *ProcessState) success() bool {
  87         return p.status.ExitStatus() == 0
  88 }
  89
  90 func (p *ProcessState) sys() any {
  91         return p.status
  92 }
  93
  94 func (p *ProcessState) sysUsage() any {
  95         return p.rusage
  96 }
  97
  98 func (p *ProcessState) String() string {
  99         if p == nil {
 100                 return "<nil>"
 101         }
 102         status := p.Sys().(syscall.WaitStatus)
 103         res := ""
 104         switch {
 105         case status.Exited():
 106                 code := status.ExitStatus()
 107                 if runtime.GOOS == "windows" && uint(code) >= 1<<16 { // windows uses large hex numbers
 108                         res = "exit status " + uitox(uint(code))
 109                 } else { // unix systems use small decimal integers
 110                         res = "exit status " + itoa.Itoa(code) // unix
 111                 }
 112         case status.Signaled():
 113                 res = "signal: " + status.Signal().String()
 114         case status.Stopped():
 115                 res = "stop signal: " + status.StopSignal().String()
 116                 if status.StopSignal() == syscall.SIGTRAP && status.TrapCause() != 0 {
 117                         res += " (trap " + itoa.Itoa(status.TrapCause()) + ")"
 118                 }
 119         case status.Continued():
 120                 res = "continued"
 121         }
 122         if status.CoreDump() {
 123                 res += " (core dumped)"
 124         }
 125         return res
 126 }
 127
 128 // ExitCode returns the exit code of the exited process, or -1
 129 // if the process hasn't exited or was terminated by a signal.
 130 func (p *ProcessState) ExitCode() int {
 131         // return -1 if the process hasn't started.
 132         if p == nil {
 133                 return -1
 134         }
 135         return p.status.ExitStatus()
 136 }