cmd_linux.go

//go:build linux

package gosh

import (
	"fmt"
	"os/exec"
	"syscall"

	"github.com/go-logr/logr"
)

// A Cmd is a wrapper for building os/exec.Cmd's
type Cmd struct {
	*exec.Cmd
	RawCmd []string
	// BuilderError is set if a builder method like FileOut fails. Run() and Start() will return this error if set. Further builder methods will do nothing if this is set.
	BuilderError    error
	UseProcessGroup bool
	Log             logr.Logger
	deferredBefore  []func() error
	deferredAfter   []func() error
}

// UsingProcessGroup marks this Cmd to create a new process group.
// If this is not done, calling Kill() will not kill any subprocesses this Cmd spawns,
// causing Wait() to never return.
// This is not necessary if you are not planning on Kill()'ing this Cmd, or are 100% certain it
// will not spawn any subprocesses.
func (c *Cmd) UsingProcessGroup() *Cmd {
	c.UseProcessGroup = true
	c.Cmd.SysProcAttr = &syscall.SysProcAttr{Setpgid: true}
	return c
}

// Kill implements Commander
func (c *Cmd) Kill() error {
	if c.Cmd.Process == nil {
		return ErrNotStarted
	}
	c.log().V(CommandLogLevel).Info(fmt.Sprintf("killing: %v", c.AsShellArgs()), "pid", c.Process.Pid)
	if c.UseProcessGroup {
		pgid, err := syscall.Getpgid(c.Process.Pid)
		if err != nil {
			return err
		}
		err = syscall.Kill(-pgid, syscall.SIGTERM)
		if err != nil {
			return err
		}
	}
	return c.Cmd.Process.Signal(syscall.SIGTERM)
}