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

80 lines
1.4 KiB
Go

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
}