Python使用subprocess模块轻松调用外部程序与命令

import subprocess
# 执行ls命令，获取当前目录下的文件列表
result = subprocess.run(['ls', '-l'], capture_output=True, text=True)
if result.returncode == 0:
    print("命令执行成功，输出如下：")
    print(result.stdout)
else:
    print(f"命令执行失败，错误信息：{result.stderr}")

import subprocess
# 执行一个错误的命令，捕获输出和错误
result = subprocess.run(['ls', 'nonexistent_file'], stdout=subprocess.PIPE, stderr=subprocess.PIPE, text=True)
print("标准输出：", result.stdout)
print("标准错误：", result.stderr)
#输出为：
标准输出： 
标准错误： ls: nonexistent_file: No such file or directory

import subprocess
# 执行一个错误的命令，捕获输出和错误
result = subprocess.run(['ls', 'nonexistent_file'],capture_output=True, text=True)
print("标准输出：", result.stdout)
print("标准错误：", result.stderr)

import subprocess
# 执行一个错误的命令，捕获输出和错误
result = subprocess.run('ls nonexistent_file',shell=True,capture_output=True, text=True)
print("标准输出：", result.stdout)
print("标准错误：", result.stderr)

import subprocess
user_input = "; rm -rf /"# 恶意输入示例
# 危险操作！可能会删除系统根目录
subprocess.run(f'echo {user_input}', shell=True)

import subprocess
# 在/tmp目录下执行ls命令
result = subprocess.run(['ls'], cwd='/tmp', capture_output=True, text=True)
print(result.stdout)

import subprocess
try:
# 执行ping命令，设置超时时间为5秒
    result = subprocess.run(['ping', 'www.baidu.com'], timeout=5, capture_output=True, text=True)
    print(result.stdout)
except subprocess.TimeoutExpired:
    print("命令执行超时！")

import subprocess
try:
# 执行一个可能失败的命令，开启check检查
 result = subprocess.run(['ls','nonexistent_file'], check=True, capture_output=True, text=True)
except subprocess.CalledProcessError:
 print("命令执行失败！")

import subprocess
# 正确写法：列表形式
p = subprocess.Popen(['ls', '-l'], stdout=subprocess.PIPE)
# 危险写法（shell=True）：
# p = subprocess.Popen('ls -l', shell=True)

import subprocess
# 执行命令并实时获取输出
p = subprocess.Popen(['ping', 'www.baidu.com'], stdout=subprocess.PIPE, text=True)
# 逐行读取输出
for line in iter(p.stdout.readline, ''):
    print(line.strip())
p.wait()  # 等待进程结束

# 安全风险示例（切勿在生产环境使用）
user_input = "example.txt; rm -rf /"
subprocess.Popen(f'cat {user_input}', shell=True)

import subprocess
# 在/tmp目录下执行命令
p = subprocess.Popen(['ls'], cwd='/tmp', stdout=subprocess.PIPE)
print(p.stdout.read().decode())

import subprocess
import os
# 自定义环境变量
my_env = {**os.environ, 'MY_VAR': 'custom_value'}
p = subprocess.Popen(['printenv', 'MY_VAR'], env=my_env, stdout=subprocess.PIPE)
print(p.stdout.read().decode())  # 输出: custom_value

# 无缓冲模式，实时获取输出
p = subprocess.Popen(['ls'], stdout=subprocess.PIPE, bufsize=0)

# 在Windows或Linux上创建新会话
p = subprocess.Popen(['python', 'script.py'], start_new_session=True)

import subprocess
# 实时监控日志文件
p = subprocess.Popen(['tail', '-f', '/var/log/syslog'], stdout=subprocess.PIPE, text=True)
try:
    for line in iter(p.stdout.readline, ''):
        print(f"日志: {line.strip()}")
except KeyboardInterrupt:
    p.terminate()  # 按Ctrl+C终止监控

import subprocess
import time
# 并行执行多个命令
commands = [
    ['sleep', '2'],
    ['ls', '-l'],
    ['echo', 'Hello']
]
processes = [subprocess.Popen(cmd) for cmd in commands]
# 等待所有进程结束
for p in processes:
    p.wait()
print("所有命令执行完毕")

import subprocess
# 启动交互式FTP客户端
p = subprocess.Popen(['ftp', 'ftp.example.com'], 
stdin=subprocess.PIPE, 
stdout=subprocess.PIPE,
stderr=subprocess.PIPE,text=True)
# 发送登录命令
p.stdin.write('user\n')
p.stdin.write('password\n')
p.stdin.flush()
# 读取响应
output = p.stdout.read(1024)

import subprocess
try:
    result = subprocess.check_output(['df', '-h'], text=True)
    print("磁盘空间信息：")
    print(result)
except subprocess.CalledProcessError as e:
    print(f"命令执行失败，错误码：{e.returncode}，错误信息：{e.output}")