func Example() {
var output [2]string
cmds := []*exec.Cmd{
exec.Command("sh", "-c", "echo stderr 1>&2"),
exec.Command("sh", "-c", "echo stdout"),
}
closed := 0
lines, started, exited := cmdplx.Start(cmds)
for {
select {
case line := <-lines:
if line == nil {
lines = nil
if closed++; closed == 3 {
goto DONE
}
break
}
if err := line.Err(); err != nil {
if err != io.EOF {
fmt.Println(err)
}
break
}
output[line.From()-1] = line.Text()
case status := <-started:
if status == nil {
started = nil
if closed++; closed == 3 {
goto DONE
}
break
}
if err := status.Err(); err != nil {
fmt.Println(err)
}
case status := <-exited:
if status == nil {
exited = nil
if closed++; closed == 3 {
goto DONE
}
break
}
if err := status.Err(); err != nil {
fmt.Println(err)
}
}
}
DONE:
fmt.Println(output)
// Output:
// [stdout stderr]
}
func Example_simple() {
var output [2]string
lines, _, _ := cmdplx.Start([]*exec.Cmd{
exec.Command("sh", "-c", "echo stderr 1>&2"),
exec.Command("sh", "-c", "echo stdout"),
})
for line := range lines {
if err := line.Err(); err == nil {
output[line.From()-1] = line.Text()
}
}
fmt.Println(output)
// Output:
// [stdout stderr]
}
func TestStart(t *testing.T) {
cmds := []*exec.Cmd{
exec.Command("sh", "-c", "echo hello 1>&2"),
exec.Command("sh", "-c", "echo world"),
exec.Command("nosuchcommand"),
exec.Command("sh", "-c", "exit 1"),
}
lines, started, exited := cmdplx.Start(cmds)
closed := 0
var (
exitError *cmdplx.Status
commandNotFound *cmdplx.Status
)
for {
select {
case line := <-lines:
if line == nil {
lines = nil
if closed++; closed == 3 {
goto DONE
}
break
}
if line.From() == 1 {
if text := line.Text(); text != "world" {
t.Errorf("expect 'world', got %s", text)
}
}
if line.From() == 2 {
if text := line.Text(); text != "hello" {
t.Errorf("expect 'hello', got %s", text)
}
}
case status := <-started:
if status == nil {
started = nil
if closed++; closed == 3 {
goto DONE
}
break
}
if err := status.Err(); err != nil {
commandNotFound = status
}
case status := <-exited:
if status == nil {
exited = nil
if closed++; closed == 3 {
goto DONE
}
break
}
if err := status.Err(); err != nil {
exitError = status
}
}
}
DONE:
if exitError == nil || exitError.Cmd() != cmds[3] {
t.Errorf("wrong exit status")
}
if commandNotFound == nil || commandNotFound.Cmd() != cmds[2] {
t.Errorf("wrong command not found status")
}
}