1 files changed, 149 insertions, 0 deletions
diff --git a/src/os/exec_plan9.go b/src/os/exec_plan9.go
new file mode 100644
index 0000000..69714ff
--- /dev/null
+++ b/src/os/exec_plan9.go
@@ -0,0 +1,149 @@
+// 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 (
+	"internal/itoa"
+	"runtime"
+	"syscall"
+	"time"
+)
+
+// The only signal values guaranteed to be present in the os package
+// on all systems are Interrupt (send the process an interrupt) and
+// Kill (force the process to exit). Interrupt is not implemented on
+// Windows; using it with os.Process.Signal will return an error.
+var (
+	Interrupt Signal = syscall.Note("interrupt")
+	Kill      Signal = syscall.Note("kill")
+)
+
+func startProcess(name string, argv []string, attr *ProcAttr) (p *Process, err error) {
+	sysattr := &syscall.ProcAttr{
+		Dir: attr.Dir,
+		Env: attr.Env,
+		Sys: attr.Sys,
+	}
+
+	sysattr.Files = make([]uintptr, 0, len(attr.Files))
+	for _, f := range attr.Files {
+		sysattr.Files = append(sysattr.Files, f.Fd())
+	}
+
+	pid, h, e := syscall.StartProcess(name, argv, sysattr)
+	if e != nil {
+		return nil, &PathError{Op: "fork/exec", Path: name, Err: e}
+	}
+
+	return newProcess(pid, h), nil
+}
+
+func (p *Process) writeProcFile(file string, data string) error {
+	f, e := OpenFile("/proc/"+itoa.Itoa(p.Pid)+"/"+file, O_WRONLY, 0)
+	if e != nil {
+		return e
+	}
+	defer f.Close()
+	_, e = f.Write([]byte(data))
+	return e
+}
+
+func (p *Process) signal(sig Signal) error {
+	if p.done() {
+		return ErrProcessDone
+	}
+	if e := p.writeProcFile("note", sig.String()); e != nil {
+		return NewSyscallError("signal", e)
+	}
+	return nil
+}
+
+func (p *Process) kill() error {
+	return p.signal(Kill)
+}
+
+func (p *Process) wait() (ps *ProcessState, err error) {
+	var waitmsg syscall.Waitmsg
+
+	if p.Pid == -1 {
+		return nil, ErrInvalid
+	}
+	err = syscall.WaitProcess(p.Pid, &waitmsg)
+	if err != nil {
+		return nil, NewSyscallError("wait", err)
+	}
+
+	p.setDone()
+	ps = &ProcessState{
+		pid:    waitmsg.Pid,
+		status: &waitmsg,
+	}
+	return ps, nil
+}
+
+func (p *Process) release() error {
+	// NOOP for Plan 9.
+	p.Pid = -1
+	// no need for a finalizer anymore
+	runtime.SetFinalizer(p, nil)
+	return nil
+}
+
+func findProcess(pid int) (p *Process, err error) {
+	// NOOP for Plan 9.
+	return newProcess(pid, 0), nil
+}
+
+// ProcessState stores information about a process, as reported by Wait.
+type ProcessState struct {
+	pid    int              // The process's id.
+	status *syscall.Waitmsg // System-dependent status info.
+}
+
+// Pid returns the process id of the exited process.
+func (p *ProcessState) Pid() int {
+	return p.pid
+}
+
+func (p *ProcessState) exited() bool {
+	return p.status.Exited()
+}
+
+func (p *ProcessState) success() bool {
+	return p.status.ExitStatus() == 0
+}
+
+func (p *ProcessState) sys() any {
+	return p.status
+}
+
+func (p *ProcessState) sysUsage() any {
+	return p.status
+}
+
+func (p *ProcessState) userTime() time.Duration {
+	return time.Duration(p.status.Time[0]) * time.Millisecond
+}
+
+func (p *ProcessState) systemTime() time.Duration {
+	return time.Duration(p.status.Time[1]) * time.Millisecond
+}
+
+func (p *ProcessState) String() string {
+	if p == nil {
+		return "<nil>"
+	}
+	return "exit status: " + p.status.Msg
+}
+
+// ExitCode returns the exit code of the exited process, or -1
+// if the process hasn't exited or was terminated by a signal.
+func (p *ProcessState) ExitCode() int {
+	// return -1 if the process hasn't started.
+	if p == nil {
+		return -1
+	}
+	return p.status.ExitStatus()
+}