add tee (nao1215#66)

internal/applets/applet.go

@@ -68,6 +68,7 @@ import (
 	"github.com/nao1215/mimixbox/internal/applets/shellutils/serial"
 	"github.com/nao1215/mimixbox/internal/applets/shellutils/sleep"
 	"github.com/nao1215/mimixbox/internal/applets/shellutils/sync"
+	"github.com/nao1215/mimixbox/internal/applets/shellutils/tee"
 	"github.com/nao1215/mimixbox/internal/applets/shellutils/true"
 	"github.com/nao1215/mimixbox/internal/applets/shellutils/uuidgen"
 	"github.com/nao1215/mimixbox/internal/applets/shellutils/wget"
@@ -155,6 +156,7 @@ func init() {
 		"sync":         {sync.Run, "Synchronize cached writes to persistent storage"},
 		"tac":          {tac.Run, "Print the file contents from the end to the beginning"},
 		"tail":         {tail.Run, "Print the last NUMBER(default=10) lines"},
+		"tee":          {tee.Run, "Read from standard input and write to standard output and files"},
 		"touch":        {touch.Run, "Update the access and modification times of each FILE to the current time"},
 		"tr":           {tr.Run, "Translate or delete characters"},
 		"true":         {true.Run, "Do nothing. Return success(0)"},

internal/applets/shellutils/tee/tee.go

@@ -0,0 +1,75 @@
+package tee
+
+import (
+	"io"
+	"os"
+	"os/signal"
+	"syscall"
+
+	"github.com/jessevdk/go-flags"
+	mb "github.com/nao1215/mimixbox/internal/lib"
+)
+
+type options struct {
+	Version      bool `short:"v" long:"version" description:"print version and exit"`
+	Append       bool `short:"a" long:"append" description:"append to files, do not overwrite"`
+	IgnoreSIGINT bool `short:"i" long:"ignore-interrupts" description:"ignore SIGINT"`
+}
+
+const cmdName string = "tee"
+const version = "1.0.1"
+
+func initParser(opts *options) *flags.Parser {
+	parser := flags.NewParser(opts, flags.Default)
+	parser.Name = cmdName
+	parser.Usage = "[OPTIONS]"
+
+	return parser
+}
+
+func Run() (int, error) {
+	var opts options
+	args, err := initParser(&opts).Parse()
+	if err != nil {
+		return mb.ExitFailure, err
+	}
+
+	if opts.Version {
+		mb.ShowVersion(cmdName, version)
+		os.Exit(mb.ExitSuccess)
+	}
+
+	openFlags := os.O_WRONLY | os.O_CREATE
+	if opts.Append {
+		openFlags |= os.O_APPEND
+	}
+
+	if opts.IgnoreSIGINT {
+		sigs := make(chan os.Signal, 1)
+		signal.Notify(sigs, syscall.SIGINT)
+		go func() {
+			for range sigs {
+			}
+		}()
+
+	}
+
+	files := make([]io.Writer, 0, 1+len(args))
+	files = append(files, os.Stdout)
+	for _, filename := range args {
+		f, err := os.OpenFile(filename, openFlags, 0644)
+		if err != nil {
+			return mb.ExitFailure, err
+		}
+		files = append(files, f)
+		defer f.Close()
+	}
+
+	multiwriter := io.MultiWriter(files...)
+	_, err = io.Copy(multiwriter, os.Stdin)
+	if err != nil {
+		return mb.ExitFailure, err
+	}
+
+	return mb.ExitSuccess, nil
+}