Update vendors

vendor/github.com/cosiner/argv/cmd.go

@@ -0,0 +1,79 @@
+package argv
+
+import (
+	"bytes"
+	"errors"
+	"io"
+	"os/exec"
+	"strings"
+)
+
+// Run execute cmdline string and return the output
+func Run(cmdline []rune, env map[string]string) ([]rune, error) {
+	args, err := Argv(cmdline, env, Run)
+	if err != nil {
+		return nil, err
+	}
+	cmds, err := Cmds(args)
+	if err != nil {
+		return nil, err
+	}
+
+	output := bytes.NewBuffer(make([]byte, 0, 1024))
+	err = Pipe(nil, output, cmds...)
+	str := output.String()
+	str = strings.TrimSpace(str)
+	return []rune(str), err
+}
+
+// Cmds generate exec.Cmd for each command.
+func Cmds(args [][]string) ([]*exec.Cmd, error) {
+	var cmds []*exec.Cmd
+	for _, argv := range args {
+		if len(argv) == 0 {
+			return nil, errors.New("invalid cmd")
+		}
+
+		cmds = append(cmds, exec.Command(argv[0], argv[1:]...))
+	}
+	return cmds, nil
+}
+
+// Pipe pipe previous command's stdout to next command's stdin, if in or
+// out is nil, it will be ignored.
+func Pipe(in io.Reader, out io.Writer, cmds ...*exec.Cmd) error {
+	l := len(cmds)
+	if l == 0 {
+		return nil
+	}
+
+	var err error
+	for i := 1; i < l; i++ {
+		cmds[i].Stdin, err = cmds[i-1].StdoutPipe()
+		if err != nil {
+			break
+		}
+	}
+	if err != nil {
+		return err
+	}
+	if in != nil {
+		cmds[0].Stdin = in
+	}
+	if out != nil {
+		cmds[l-1].Stdout = out
+	}
+	for i := range cmds {
+		err = cmds[i].Start()
+		if err != nil {
+			return err
+		}
+	}
+	for i := range cmds {
+		err = cmds[i].Wait()
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}