Python建立SSH连接后，如何执行远程Bash命令？

Hey there! Let's fix your issue with running remote commands via SSH in Python. The problem with your current code is that each os.system() call runs as a separate local process—so when you run ssh -X ubuntu@192.168.0.2, it starts an interactive SSH session, but the next os.system('cd Desktop') runs locally on your machine, not the remote one. They don't share the same shell session at all.

Here are a few solid ways to execute remote Bash commands properly:

1. Pass Remote Commands Directly in the SSH Call #

You can bundle the remote commands you want to run right into the ssh command itself. Use quotes to wrap the commands, and && to chain them so they run in the same remote shell:

import os

def livestream():
    # Chain commands with && to run them in the same remote shell
    os.system('ssh -X ubuntu@192.168.0.2 "cd Desktop && ./your_target_program"')

This works because the entire quoted string is executed as a single command on the remote machine. The cd Desktop changes the working directory, then ./your_target_program runs your desired app.

2. Use subprocess (Recommended Over os.system) #

The subprocess module is more flexible than os.system—it lets you capture output, handle errors, and avoid shell injection risks more easily. Here's how to use it:

import subprocess

def livestream():
    # Define the remote command chain
    remote_cmd = "cd Desktop && ./your_target_program"
    # Build the SSH command list (avoids shell escaping issues)
    ssh_cmd = ["ssh", "-X", "ubuntu@192.168.0.2", remote_cmd]
    
    # Run the command and capture output
    result = subprocess.run(ssh_cmd, capture_output=True, text=True)
    
    # Check results
    if result.returncode == 0:
        print("Command ran successfully! Output:\n", result.stdout)
    else:
        print("Command failed. Error:\n", result.stderr)

3. Use a Dedicated SSH Library (For Complex Workflows) #

If you need to run multiple commands, transfer files, or maintain a persistent SSH session, use a library like paramiko (you'll need to install it first with pip install paramiko):

import paramiko

def livestream():
    ssh_client = paramiko.SSHClient()
    # Auto-add the remote host key (for testing; in production, use known_hosts)
    ssh_client.set_missing_host_key_policy(paramiko.AutoAddPolicy())
    
    try:
        # Connect to the remote machine
        ssh_client.connect(hostname="192.168.0.2", username="ubuntu")
        
        # Execute the remote command
        stdin, stdout, stderr = ssh_client.exec_command("cd Desktop && ./your_target_program")
        
        # Read output and errors
        output = stdout.read().decode("utf-8")
        error = stderr.read().decode("utf-8")
        
        print("Remote Output:\n", output)
        if error:
            print("Remote Errors:\n", error)
    finally:
        # Always close the connection
        ssh_client.close()

Each method has its use case:

• Use the first approach for quick, simple one-liners.
• Use subprocess when you need better control over input/output.
• Use paramiko for advanced SSH tasks like multiple commands or file transfers.

内容的提问来源于stack exchange，提问作者user7441