Implement kill -s

kill/kill.go

@@ -0,0 +1,102 @@
+package main
+
+import (
+	"errors"
+	"fmt"
+	"os"
+	"syscall"
+
+	"github.com/alexflint/go-arg"
+	common "source.heropunch.io/tomo/go-coreutils"
+)
+
+var BadSignalName = errors.New("bad signal name")
+
+func selectSignal(signame string) (syscall.Signal, error) {
+	switch signame {
+	case "TERM":
+		return syscall.SIGTERM, nil
+	case "KILL":
+		return syscall.SIGKILL, nil
+	case "PIPE":
+		return syscall.SIGPIPE, nil
+	case "INT":
+		return syscall.SIGINT, nil
+	case "QUIT":
+		return syscall.SIGQUIT, nil
+	case "SEGV":
+		return syscall.SIGSEGV, nil
+	case "STOP":
+		return syscall.SIGSTOP, nil
+	case "CONT":
+		return syscall.SIGCONT, nil
+	case "0":
+		return 0, nil
+	case "ABRT":
+		return syscall.SIGABRT, nil
+	case "ALRM":
+		return syscall.SIGALRM, nil
+	case "BUS":
+		return syscall.SIGBUS, nil
+	case "CHLD":
+		return syscall.SIGCHLD, nil
+	case "FPE":
+		return syscall.SIGFPE, nil
+	case "HUP":
+		return syscall.SIGHUP, nil
+	case "ILL":
+		return syscall.SIGILL, nil
+	case "TSTP":
+		return syscall.SIGTSTP, nil
+	case "TTIN":
+		return syscall.SIGTTIN, nil
+	case "TTOU":
+		return syscall.SIGTTOU, nil
+	case "USR1":
+		return syscall.SIGUSR1, nil
+	case "USR2":
+		return syscall.SIGUSR2, nil
+	case "URG":
+		return syscall.SIGURG, nil
+	default:
+		return -1, BadSignalName
+	}
+}
+
+func main() {
+	var args struct {
+		SignalName string `arg:"-s"`
+		List       int    `arg:"-l"`
+		PIDs       []int  `arg:"positional"`
+	}
+
+	args.SignalName = "TERM"
+	args.List = -1
+
+	p := arg.MustParse(&args)
+	if len(os.Args) == 1 {
+		p.WriteUsage(os.Stderr)
+		os.Exit(1)
+	}
+
+	sig, err := selectSignal(args.SignalName)
+	common.ExitIfError(err)
+
+	exitCode := 0
+	if len(args.PIDs) > 0 {
+		for _, pid := range args.PIDs {
+			process, err := os.FindProcess(pid)
+			if err != nil {
+				common.PrintToStderr(fmt.Sprintf("error finding process %v: %v", pid, err))
+				exitCode = 1
+				continue
+			}
+			err = process.Signal(sig)
+			if err != nil {
+				common.PrintToStderr(fmt.Sprintf("kill %v: %v", pid, err))
+				exitCode = 1
+			}
+		}
+	}
+	os.Exit(exitCode)
+}