我有两个问题需要帮助。我想我已经把它缩小到在 goroutine 中使用 io.Copy 。它的行为就像标准输入需要使用回车键“重新激活”。
感谢您提供的任何帮助。这是我在这里的第一篇文章。
package main
import (
"fmt"
"io"
"log"
"net"
"os"
"time"
"golang.org/x/crypto/ssh"
)
var (
stdout, stderr io.Reader
stdin io.WriteCloser
timeout = 30 * time.Second
)
func sshConfig() *ssh.ClientConfig {
config := &ssh.ClientConfig{
User: MYUSER,
Auth: []ssh.AuthMethod{
ssh.Password(MYPASS),
},
HostKeyCallback: ssh.HostKeyCallback(func(hostname string, remote net.Addr, key ssh.PublicKey) error { return nil }),
Timeout: timeout,
}
return config
}
func options() {
menuString := `
Enter 1 for "uptime"
Enter 2 for "ping -c 20 www.google.com"
Type exit to exit
`
for i := 0; i <= 5; i++ {
var num, cmd string
fmt.Println(menuString)
if i == 0 {
fmt.Print("Select an option from above: ")
} else {
fmt.Println("You'll have to press enter before entering your option. Why?")
fmt.Print("Select an option from above: ")
}
fmt.Scanln(&num)
switch num {
case "1":
cmd = "uptime"
connect(cmd)
case "2":
cmd = "ping -c 20 www.google.com"
connect(cmd)
case "exit":
fmt.Println("exiting")
os.Exit(0)
default:
fmt.Println("Invalid response")
fmt.Println("Select an option from above: ")
}
}
}
func connect(c string) {
config := sshConfig()
conn, err := ssh.Dial("tcp", "127.0.0.1:22", config)
defer conn.Close()
if err != nil {
log.Fatal("dial target error:", err)
}
session, err := conn.NewSession()
defer session.Close()
if err != nil {
log.Fatalf("session failed:%v", err)
}
defer session.Close()
modes := ssh.TerminalModes{
ssh.ECHO: 0, // disable echoing
ssh.TTY_OP_ISPEED: 14400, // input speed = 14.4kbaud
ssh.TTY_OP_OSPEED: 14400, // output speed = 14.4kbaud
}
err = session.RequestPty("xterm", 80, 40, modes)
if err != nil {
log.Fatalf("Pty request failed:%v", err)
}
stdin, err = session.StdinPipe()
if err != nil {
log.Fatalf("Unable to setup stdin for session: %v", err)
}
stdout, err = session.StdoutPipe()
if err != nil {
log.Fatalf("Unable to setup stdout for session: %v", err)
}
stderr, err = session.StderrPipe()
if err != nil {
log.Fatalf("Unable to setup stderr for session: %v", err)
}
quit := make(chan bool)
go func() {
for {
select {
case <-quit:
fmt.Println("exiting goroutine")
return
default:
fmt.Println("go routine is running")
io.Copy(os.Stdout, stdout)
io.Copy(stdin, os.Stdin)
io.Copy(os.Stderr, stderr)
}
}
}()
if err := session.Run(c); err != nil {
log.Fatal("Failed to run: " + err.Error())
}
fmt.Println("closing the channel")
close(quit)
fmt.Println("the channel is closed")
}
func main() {
options()
}
最佳答案
首先,io.Copy 是一个阻塞调用,它将 io.writer 的缓冲区复制到 io.reader 直到在 src 上达到 EOF 或发生错误。 Here's来自 golang 的 io 模块的片段:
// copyBuffer is the actual implementation of Copy and CopyBuffer.
// if buf is nil, one is allocated.
func copyBuffer(dst Writer, src Reader, buf []byte) (written int64, err error) {
// If the reader has a WriteTo method, use it to do the copy.
// Avoids an allocation and a copy.
if wt, ok := src.(WriterTo); ok {
return wt.WriteTo(dst)
}
// Similarly, if the writer has a ReadFrom method, use it to do the copy.
if rt, ok := dst.(ReaderFrom); ok {
return rt.ReadFrom(src)
}
if buf == nil {
size := 32 * 1024
if l, ok := src.(*LimitedReader); ok && int64(size) > l.N {
if l.N < 1 {
size = 1
} else {
size = int(l.N)
}
}
buf = make([]byte, size)
}
for {
nr, er := src.Read(buf)
if nr > 0 {
nw, ew := dst.Write(buf[0:nr])
if nw > 0 {
written += int64(nw)
}
if ew != nil {
err = ew
break
}
if nr != nw {
err = ErrShortWrite
break
}
}
if er != nil {
if er != EOF {
err = er
}
break
}
}
return written, err
}
现在回答你的问题当在第一次迭代中对 session 的 stdin 和 stderr 进行 io.copy 调用时,它会等到 stderr 和 stdin 上有一条消息被复制并被阻止。
只需将您的 goroutine 替换为复制 stdout 即可为您提供每次迭代的预期行为。类似地,stderr,stdin 需要由它们自己的 goroutine 管理:
go func() {
for {
io.Copy(os.Stdout, stdout)
}
}()
SigTerm 将用于终止 session ,有一个称为中断的 posix 信号可用于中断 cmd。 Here's一个列表 os all POSIX 表明您使用的 ssh 库支持。这是中断信号和预期行为的演示:
package main
import (
"fmt"
"io"
"log"
"net"
"os"
"time"
"golang.org/x/crypto/ssh"
)
var (
stdout, stderr io.Reader
stdin io.WriteCloser
timeout = 30 * time.Second
)
const (
MYUSER = ""
MYPASS = ""
)
func sshConfig() *ssh.ClientConfig {
config := &ssh.ClientConfig{
User: MYUSER,
Auth: []ssh.AuthMethod{
ssh.Password(MYPASS),
},
HostKeyCallback: ssh.HostKeyCallback(func(hostname string, remote net.Addr, key ssh.PublicKey) error { return nil }),
Timeout: timeout,
}
return config
}
func options() {
menuString := `
Enter 1 for "uptime"
Enter 2 for "ping -c 20 www.google.com"
Type exit to exit
`
for i := 0; i <= 5; i++ {
var num, cmd string
fmt.Println(menuString)
if i == 0 {
fmt.Print("Select an option from above: ")
} else {
fmt.Println("You'll have to press enter before entering your option. Why?")
fmt.Print("Select an option from above: ")
}
fmt.Scanln(&num)
switch num {
case "1":
cmd = "uptime"
connect(cmd)
case "2":
cmd = "ping -c 20 www.google.com"
connect(cmd)
case "exit":
fmt.Println("exiting")
os.Exit(0)
default:
fmt.Println("Invalid response")
fmt.Println("Select an option from above: ")
}
}
}
func connect(c string) {
config := sshConfig()
conn, err := ssh.Dial("tcp", "127.0.0.1:22", config)
defer conn.Close()
if err != nil {
log.Fatal("dial target error:", err)
}
session, err := conn.NewSession()
defer session.Close()
if err != nil {
log.Println("session failed:%v", err)
}
defer session.Close()
modes := ssh.TerminalModes{
ssh.ECHO: 0, // disable echoing
ssh.TTY_OP_ISPEED: 14400, // input speed = 14.4kbaud
ssh.TTY_OP_OSPEED: 14400, // output speed = 14.4kbaud
}
err = session.RequestPty("xterm", 80, 40, modes)
if err != nil {
log.Fatalf("Pty request failed:%v", err)
}
stdin, err = session.StdinPipe()
if err != nil {
log.Fatalf("Unable to setup stdin for session: %v", err)
}
stdout, err = session.StdoutPipe()
if err != nil {
log.Fatalf("Unable to setup stdout for session: %v", err)
}
stderr, err = session.StderrPipe()
if err != nil {
log.Fatalf("Unable to setup stderr for session: %v", err)
}
go func() {
for {
io.Copy(os.Stdout, stdout)
}
}()
c = "echo 'go is awesome' && sleep 10 && " + c
go func() {
time.Sleep(1 * time.Second)
session.Signal(ssh.SIGINT)
}()
if err := session.Run(c); err != nil {
log.Println("Failed to run: " + err.Error())
}
fmt.Println("closing the channel")
fmt.Println("the channel is closed")
}
func main() {
options()
}
关于go - SSH 脚本使用 pty 和 io.Copy 通过菜单流式输出,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/63865791/