英文:
golang exec a command on a running binary / process
问题
如果你看一下Nginx，它调用"nginx reload"来重新加载自身。有没有办法从命令行向正在运行的进程发送信号？即使主进程启动子进程，我如何向主进程发送命令以通知其子进程？
例如：
myapp start -debug // 启动服务器
myapp reload -gracefull // 优雅地停止应用程序
现在我需要发送操作系统信号来通知我的服务器执行优雅的关闭
kill -QUIT pid
kill -USR2 pid
希望我的问题足够清楚
谢谢
英文:
If you look at Nginx it calls "nginx reload" to reload itself. Is there any way to send a signal from the command line to a running process? Even if the main process starts child processes how can I send commands to the main to notify its children?
ex:
myapp start -debug // starts a server
myapp reload -gracefull // stops the app gracefully
Now i need to send os signals to notify my server to perform a graceful shutdown
kill -QUIT pid
kill -USR2 pid
I hope my question is clear enough
Thnx
答案1
得分: 7
接收信号
看一下os/signal包。
包signal实现对传入信号的访问。
文档中甚至有一个示例：
// 设置用于发送信号通知的通道。
// 我们必须使用带缓冲的通道，否则在发送信号时，如果我们还没有准备好接收，就有可能错过信号。
c := make(chan os.Signal, 1)
signal.Notify(c, os.Interrupt, os.Kill)
// 阻塞直到接收到信号。
s := <-c
fmt.Println("收到信号:", s)
发送信号
要了解如何发送信号，请查看signal_test.go，它使用了syscall。例如：
// 向该进程发送SIGHUP信号
t.Logf("sighup...")
syscall.Kill(syscall.Getpid(), syscall.SIGHUP)
waitSig(t, c, syscall.SIGHUP)
英文:
Receive signals
Take a look at the os/signal package.
> Package signal implements access to incoming signals.
There is even an example in the documentation :
// Set up channel on which to send signal notifications.
// We must use a buffered channel or risk missing the signal
// if we're not ready to receive when the signal is sent.
c := make(chan os.Signal, 1)
signal.Notify(c, os.Interrupt, os.Kill)
// Block until a signal is received.
s := <-c
fmt.Println("Got signal:", s)
Send signals
To see how to send signals take a look at signal_test.go, it uses syscall. For example :
// Send this process a SIGHUP
t.Logf("sighup...")
syscall.Kill(syscall.Getpid(), syscall.SIGHUP)
waitSig(t, c, syscall.SIGHUP)
答案2
得分: 0
我发现在Go语言中，我们可以将环境变量传递给syscall.Exec函数。
err := syscall.Exec(argv0, os.Args, os.Environ())
这段代码会将当前环境变量复制到子进程中。
英文:
I figured out that in go i we can pass the environment to syscall.Exec
err := syscall.Exec(argv0. os.Args. os.Environ())
simply copies the current env to the child process.
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