使用 Python 子进程使用 ssh 的多个命令 [英] Multiple commands with ssh using Python subprocess

问题描述

我需要使用 subprocess 模块在 ssh 会话中执行多个 shell 命令.我可以一次执行一个命令:

I need to execute multiple shell commands in a ssh session using the subprocess module. I am able to execute one command at a time with:

   subprocess.Popen(["ssh",  "-o UserKnownHostsFile=/dev/null", "-o StrictHostKeyChecking=no", "%s" % <HOST>, <command>])

但是有没有办法在 ssh 会话中使用 subprocess 执行多个 shell 命令?如果可能，我不想使用包.

But is there a way to execute multiple shell commands with subprocess in a ssh session? If possible, I don't want to use packages.

非常感谢！

推荐答案

严格来说，无论您在远程服务器上执行多少条命令，您都只能使用 Popen 执行一个命令.该命令是 ssh.

Strictly speaking you are only executing one command with Popen no matter how many commands you execute on the remote server. That command is ssh.

要在远程服务器上执行多个命令，只需将它们传递到由 ;s 分隔的 command 字符串中:

To have multiple commands executed on the remote server just pass them in your command string seperated by ;s:

commands = ["echo 'hi'",  "echo 'another command'"]
subprocess.Popen([
    "ssh",
    "-o UserKnownHostsFile=/dev/null",
    "-o StrictHostKeyChecking=no",
    ";".join(commands)
])

如果您希望每个命令仅在前一个命令成功时执行，您也可以在 && 上加入命令.

You could alternatively join commands on && if you wanted each command to only execute if the previous command had succeeded.

如果您有很多命令并且您担心可能会超出 命令行限制，您可以在远程服务器上使用 -s 选项执行 sh(或 bash)，这将在您发送命令时一一执行:

If you have many commands and you are concerned that you might exceed the command line limits, you could execute sh (or bash) with the -s option on the remote server, which will execute commands one-by-one as you send them:

p = subprocess.Popen([
    "ssh",
    "-o UserKnownHostsFile=/dev/null",
    "-o StrictHostKeyChecking=no",
    "sh -s",
], stdin=subprocess.PIPE)

for command in commands:
    p.stdin.write(command)
    p.stdin.write("\n")
    p.flush()

p.communicate()

请注意，在 Python3 中，您需要将命令编码为字节字符串 (command.encode("utf8"))，然后再将其写入到子进程.

Note that in Python3 you will need to encode the command to a byte string (command.encode("utf8")) before writing it to the stdin of the subprocess.

尽管最初的建议最简单，但我觉得这对于大多数简单的情况来说都是过度的.

I feel like this is overkill for most simple situations though where the initial suggest is simplest.

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