imp oot int shell. root let nbsp 发送数据
官网介绍:https://docs.python.org/3/library/subprocess.html
- Popen():
- [[email protected]/* */ scripts]# cat sub_popen.py
- #!/usr/bin/python
- #coding=utf8
- import subprocess
- child = subprocess.Popen(['ls','-l'],shell=True)
- print(type(child))
- print('parent')
- [[email protected]/* */ scripts]# python sub_popen.py
- <class 'subprocess.Popen'>
- parent
- stu_subprocess.py sub_popen.py
- 如果将不添加shell,使用默认的:
- [[email protected]/* */ scripts]# cat sub_popen.py
- #!/usr/bin/python
- #coding=utf8
- import subprocess
- child = subprocess.Popen(['ls','-l'],shell=False) shell参数默认为False
- print(type(child))
- print('parent')
- [[email protected]/* */ scripts]# python sub_popen.py
- <class 'subprocess.Popen'>
- parent
- total 8
- -rw-r--r-- 1 root root 256 Aug 21 15:26 stu_subprocess.py
- -rw-r--r-- 1 root root 136 Aug 21 15:41 sub_popen.py
- Popen不会阻塞父进程运行,Popen启动新的进程与父进程并行执行,默认父进程不等待新进程结束。
- [[email protected]/* */ scripts]# cat test_subprocess.py
- #!/usr/bin/python
- #coding=utf8
- def TestPopen():
- import subprocess
- p = subprocess.Popen(['ls','-l'],shell=True)
- for i in range(5):
- print("other things")
- print(TestPopen())
- [[email protected]/* */ scripts]# python test_subprocess.py
- other things
- other things
- other things
- other things
- other things
- None
- stu_subprocess.py sub_call.py sub_check_output.py sub_popen.py sub_run.py test_subprocess.py
- [[email protected]/* */ scripts]# cat test_subprocess1.py
- #!/usr/bin/python
- #coding=utf8
- wait(): 阻塞父进程,等待子进程运行结束再继续运行父进程
- def TestWait():
- import subprocess
- import datetime
- print(datetime.datetime.now())
- p = subprocess.Popen('sleep 10',shell=True)
- p.wait() wait()阻塞了父进程的运行,等待子进程运行完成后才继续运行父进程
- print(p.returncode)
- print(datetime.datetime.now())
- TestWait()
- [[email protected]/* */ scripts]# python test_subprocess1.py
- 2017-08-21 16:49:15.061676
- 0 当子进程运行完成结束后,返回code为0
- 2017-08-21 16:49:25.066657
- poll():判断子进程是否结束
- [[email protected]/* */ scripts]# cat test_subprocess2.py
- #!/usr/bin/python
- #coding=utf8
- def TestWait():
- import subprocess
- import datetime,time
- print(datetime.datetime.now())
- p = subprocess.Popen('sleep 10',shell=True) 子进程要睡眠10秒
- t = 1
- while (t <= 5):
- time.sleep(1)
- p.poll() 执行判断子进程,这里花了5秒
- print(p.returncode)
- t = t + 1
- print(datetime.datetime.now())
- TestWait()
- [[email protected]/* */ scripts]# python test_subprocess2.py
- 2017-08-21 16:56:33.672417
- None
- None
- None
- None
- None
- 2017-08-21 16:56:38.684795
- kill()或者terminate(): 杀掉子进程
- [[email protected]/* */ scripts]# cat test_subprocess3.py
- #!/usr/bin/python
- #coding=utf8
- def TestKillAndTerminate():
- import subprocess
- import datetime,time
- print(datetime.datetime.now())
- p = subprocess.Popen('sleep 10',shell=True)
- t = 1
- while (t <= 5):
- time.sleep(1)
- t = t + 1
- p.kill()
- print(datetime.datetime.now())
- TestKillAndTerminate()
- [[email protected]/* */ scripts]# python test_subprocess3.py
- 2017-08-21 17:03:16.315531
- 2017-08-21 17:03:21.329266
- 可以看见子进程只运行了5秒
- [[email protected]/* */ scripts]# cat sub_popen.py
- #!/usr/bin/python
- #coding=utf8
- import subprocess
- child = subprocess.Popen(['ls','-l'],shell=False)
- child.wait() 阻塞父进程,直到子进程运行完成
- print(type(child))
- print('parent')
- [[email protected]/* */ scripts]# python sub_popen.py
- total 12
- -rw-r--r-- 1 root root 256 Aug 21 15:26 stu_subprocess.py
- -rw-r--r-- 1 root root 135 Aug 21 15:47 sub_call.py
- -rw-r--r-- 1 root root 149 Aug 21 15:47 sub_popen.py
- <class 'subprocess.Popen'>
- parent
- 可以看出先运行的子进程,最后才是父进程,等待子进程运行后,再运行父进程
- 除了wait()之外还有如下:
- child.poll() # 检查子进程状态
- child.kill() # 终止子进程
- child.send_signal() # 向子进程发送信号
- child.terminate() # 终止子进程
- 子进程的PID存储在child.pid
- 子进程的标准输入、标准输出和标准错误如下属性分别表示:
- child.stdin
- child.stdout
- child.stderr
- subprocess.PIPE实际上为文本流提供一个缓存区。child的stdout将文本输出到缓存区,然后打印出缓存区的内容:
- [[email protected]/* */ scripts]# cat sub_popen.py
- #!/usr/bin/python
- #coding=utf8
- import subprocess
- child = subprocess.Popen(['ls','-l'],shell=False,stdout=subprocess.PIPE)
- print(child.stdout.read().decode('utf-8')) 打印缓存区内容,由于是bytes格式,所以转码
- print('parent')
- [[email protected]/* */ scripts]# python sub_popen.py
- total 16
- -rw-r--r-- 1 root root 256 Aug 21 15:26 stu_subprocess.py
- -rw-r--r-- 1 root root 148 Aug 21 15:53 sub_call.py
- -rw-r--r-- 1 root root 183 Aug 21 16:07 sub_popen.py
- -rw-r--r-- 1 root root 147 Aug 21 15:56 sub_run.py
- parent
- communicate()
- Popen.communicate(input=None):与子进程进行交互。向stdin发送数据,或从stdout和stderr中读取数据。可选参数input指定发送到子进程的参数。Communicate()返回一个元组:(stdoutdata, stderrdata)。注意:如果希望通过进程的stdin向其发送数据,在创建Popen对象的时候,参数stdin必须被设置为PIPE。同样,如果希望从stdout和stderr获取数据,必须将stdout和stderr设置为PIPE。
- [[email protected]/* */ scripts]# cat sub_popen.py
- #!/usr/bin/python
- #coding=utf8
- import subprocess
- child = subprocess.Popen(['ls','-l'],shell=False,stdout=subprocess.PIPE)
- #print(child.stdout.read().decode('utf-8'))
- print(child.communicate()) 返回的是标准输出,标准错误输出的tuple
- print('parent')
- [[email protected]/* */ scripts]# python sub_popen.py
- (b'total 16\n-rw-r--r-- 1 root root 256 Aug 21 15:26 stu_subprocess.py\n-rw-r--r-- 1 root root 148 Aug 21 15:53 sub_call.py\n-rw-r--r-- 1 root root 211 Aug 21 16:11 sub_popen.py\n-rw-r--r-- 1 root root 147 Aug 21 15:56 sub_run.py\n', None) NONE就是标准错误输出结果
- parent
- 可以看见先输出的子进程内容,然后才是父进程,communicate()是Popen对象的一个方法,该方法会阻塞父进程,直到子进程完成
- [[email protected]/* */ scripts]# cat sub_popen.py
- #!/usr/bin/python
- #coding=utf8
- import subprocess
- child1 = subprocess.Popen(['cat','/etc/passwd'],shell=False,stdout=subprocess.PIPE)
- child2 = subprocess.Popen(['grep','0:0'],stdin=child1.stdout, stdout=subprocess.PIPE)
- # subprocess.PIPE实际上为文本流提供一个缓存区。child1的stdout将文本输出到缓存区,随后child2的stdin从该PIPE中将文本读取走。child2的输出文本也被存放在PIPE中,直到communicate()方法从PIPE中读取出PIPE中的文本。
- out,err = child2.communicate() 因为communicate()返回的是一个元祖
- print(out) 纸打印出标准输出内容
- print('parent')
- [[email protected]/* */ scripts]# python sub_popen.py
- b'root:x:0:0:root:/root:/bin/bash\n'
- parent
- child1.stdout-->subprocess.PIPE
- child2.stdin<--subprocess.PIPE
- child2.stdout-->subprocess.PIPE
- 利用communicate()实现交互:
- [[email protected]/* */ scripts]# cat stu_subprocess.py
- #!/usr/bin/python
- #coding=utf8
- import subprocess
- child1 = subprocess.Popen(['python'],stdin=subprocess.PIPE,stdout=subprocess.PIPE,stderr=subprocess.PIPE)
- out,err = child1.communicate(b'print("hello")\nexit()') 继续给子进程输入信息
- # 启动一个子进程,然后控制其输入和输出
- print(out.decode('utf-8'))
- print('parent')
- [[email protected]/* */ scripts]# python stu_subprocess.py
- hello
- parent
- [[email protected]/* */ scripts]# cat sub_popen2.py
- #!/usr/bin/python
- #coding=utf8
- import subprocess
- obj = subprocess.Popen(["python"], stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
- obj.stdin.write(b'print("hello")\n') stdin.write和communicate两者交换使用
- obj.stdin.write(b'print("world")')
- out,err = obj.communicate()
- print(out)
- [[email protected]/* */ scripts]# python sub_popen2.py
- b'hello\nworld\n'
- call():
- subprocess.call()
- 父进程等待子进程完成
- 返回退出信息(returncode,相当于Linux exit code)
- [[email protected]/* */ scripts]# cat sub_call.py
- #!/usr/bin/python
- #coding=utf8
- import subprocess
- child = subprocess.call(['ls','-l'],shell=False)
- print(type(child))
- print('parent')
- [[email protected]/* */ scripts]# python sub_call.py
- total 12
- -rw-r--r-- 1 root root 256 Aug 21 15:26 stu_subprocess.py
- -rw-r--r-- 1 root root 135 Aug 21 15:45 sub_call.py
- -rw-r--r-- 1 root root 136 Aug 21 15:41 sub_popen.py
- <class 'int'> call函数返回的是int
- parent
- 调用call函数可以明显看出子进程阻塞了主进程的运行,先运行子进程,最后才是主进程
- [[email protected]/* */ scripts]# cat sub_call.py
- #!/usr/bin/python
- #coding=utf8
- import subprocess
- child = subprocess.call(['ls','-l'],shell=False)
- print(type(child))
- print(child) ----->returncode
- print('parent')
- [[email protected]/* */ scripts]# python sub_call.py
- total 12
- -rw-r--r-- 1 root root 256 Aug 21 15:26 stu_subprocess.py
- -rw-r--r-- 1 root root 148 Aug 21 15:53 sub_call.py
- -rw-r--r-- 1 root root 149 Aug 21 15:47 sub_popen.py
- <class 'int'>
- 0
- parent
- subprocess.call(*popenargs, **kwargs):运行命令。该函数将一直等待到子进程运行结束,并返回进程的returncode。如果子进程不需要进行交互,就可以使用该函数来创建。
- call函数返回的是returncode,也就是int类型
- 根据shell类型不同,可以更改传入call函数的args类型:
- [[email protected]/* */ scripts]# cat sub_call.py
- #!/usr/bin/python
- #coding=utf8
- import subprocess
- child = subprocess.call("ls -l",shell=True)
- print(type(child))
- print(child)
- print('parent')
- shell=True参数会让subprocess.call接受字符串类型的变量作为命令,并调用shell去执行这个字符串,当shell=False是,subprocess.call只接受数组变量作为命令,并将数组的第一个元素作为命令,剩下的全部作为该命令的参数。
- [[email protected]/* */ scripts]# python sub_call.py
- total 40
- -rw-r--r-- 1 root root 256 Aug 21 15:26 stu_subprocess.py
- -rw-r--r-- 1 root root 143 Aug 21 17:22 sub_call.py
- -rw-r--r-- 1 root root 143 Aug 21 16:33 sub_check_output.py
- -rw-r--r-- 1 root root 162 Aug 21 17:17 sub_getoutput.py
- -rw-r--r-- 1 root root 279 Aug 21 16:17 sub_popen.py
- -rw-r--r-- 1 root root 148 Aug 21 16:29 sub_run.py
- -rw-r--r-- 1 root root 257 Aug 21 16:53 test_subprocess1.py
- -rw-r--r-- 1 root root 340 Aug 21 16:52 test_subprocess2.py
- -rw-r--r-- 1 root root 332 Aug 21 17:03 test_subprocess3.py
- -rw-r--r-- 1 root root 183 Aug 21 16:44 test_subprocess.py
- <class 'int'>
- 0
- parent
- 所以当shell默认为False时,args传入的值必须是列表,而不能是str
- from subprocess import call
- import shlex
- cmd = "cat test.txt; rm test.txt"
- call(cmd, shell=True)
- shell介绍:
- https://zhidao.baidu.com/question/651286079254739125.html
- 3.5新增的run():
- class subprocess.CompletedProcess
- The return value from run(), representing a process that has finished.
- [[email protected]/* */ scripts]# cat sub_run.py
- #!/usr/bin/python
- #coding=utf8
- import subprocess
- child = subprocess.run(['ls','-l'],shell=False)
- print(type(child))
- print(child)
- print('parent')
- [[email protected]/* */ scripts]# python sub_run.py
- total 16
- -rw-r--r-- 1 root root 256 Aug 21 15:26 stu_subprocess.py
- -rw-r--r-- 1 root root 148 Aug 21 15:53 sub_call.py
- -rw-r--r-- 1 root root 149 Aug 21 15:47 sub_popen.py
- -rw-r--r-- 1 root root 147 Aug 21 15:56 sub_run.py
- <class 'subprocess.CompletedProcess'>
- CompletedProcess(args=['ls', '-l'], returncode=0)
- parent
- check_output():
- [[email protected]/* */ scripts]# cat sub_check_output.py
- #!/usr/bin/python
- #coding=utf8
- import subprocess
- child = subprocess.check_output(['ls','-l'],shell=False)
- print(type(child))
- print(child)
- print('parent')
- [[email protected]/* */ scripts]# python sub_check_output.py
- <class 'bytes'>
- b'total 20\n-rw-r--r-- 1 root root 256 Aug 21 15:26 stu_subprocess.py\n-rw-r--r-- 1 root root 148 Aug 21 15:53 sub_call.py\n-rw-r--r-- 1 root root 156 Aug 21 16:26 sub_check_output.py\n-rw-r--r-- 1 root root 279 Aug 21 16:17 sub_popen.py\n-rw-r--r-- 1 root root 147 Aug 21 15:56 sub_run.py\n'
- parent
- [[email protected]/* */ scripts]# cat sub_check_output.py
- #!/usr/bin/python
- #coding=utf8
- import subprocess
- child = subprocess.check_output(['ls','-l'],shell=False)
- print(type(child))
- print('parent')
- [[email protected]/* */ scripts]# python sub_check_output.py
- <class 'bytes'>
- parent
- 并没有打印出子进程运行后的内容
- subprocess.getoutput(cmd),返回的是一个字符串
- Return output (stdout and stderr) of executing cmd in a shell.
- [[email protected]/* */ scripts]# python sub_getoutput.py
- <class 'str'>
- stu_subprocess.py
- sub_call.py
- sub_check_output.py
- sub_getoutput.py
- sub_popen.py
- sub_run.py
- test_subprocess1.py
- test_subprocess2.py
- test_subprocess3.py
- test_subprocess.py
- [[email protected]/* */ scripts]# cat sub_getoutput.py
- #!/usr/bin/python
- #coding=utf8
- import subprocess
- def TestGetOutput():
- outp = subprocess.getoutput(["ls" ,"-l"]) 列表
- print(type(outp))
- print(outp)
- TestGetOutput()
- [[email protected]/* */ scripts]# cat sub_getoutput.py
- #!/usr/bin/python
- #coding=utf8
- import subprocess
- def TestGetOutput():
- outp = subprocess.getoutput("ls -l") 字符串
- print(type(outp))
- print(outp)
- TestGetOutput()
- [[email protected]/* */ scripts]# python sub_getoutput.py
- <class 'str'>
- total 40
- -rw-r--r-- 1 root root 256 Aug 21 15:26 stu_subprocess.py
- -rw-r--r-- 1 root root 148 Aug 21 15:53 sub_call.py
- -rw-r--r-- 1 root root 143 Aug 21 16:33 sub_check_output.py
- -rw-r--r-- 1 root root 162 Aug 21 17:17 sub_getoutput.py
- -rw-r--r-- 1 root root 279 Aug 21 16:17 sub_popen.py
- -rw-r--r-- 1 root root 148 Aug 21 16:29 sub_run.py
- -rw-r--r-- 1 root root 257 Aug 21 16:53 test_subprocess1.py
- -rw-r--r-- 1 root root 340 Aug 21 16:52 test_subprocess2.py
- -rw-r--r-- 1 root root 332 Aug 21 17:03 test_subprocess3.py
- -rw-r--r-- 1 root root 183 Aug 21 16:44 test_subprocess.py
- #接收字符串格式命令,返回元组形式,第1个元素是执行状态,第2个是命令结果
- >>> subprocess.getstatusoutput('ls -l')
- (0, 'total 40\n-rw-r--r-- 1 root root 256 Aug 21 15:26 stu_subprocess.py\n-rw-r--r-- 1 root root 143 Aug 21 17:22 sub_call.py\n-rw-r--r-- 1 root root 143 Aug 21 16:33 sub_check_output.py\n-rw-r--r-- 1 root root 162 Aug 21 17:17 sub_getoutput.py\n-rw-r--r-- 1 root root 279 Aug 21 16:17 sub_popen.py\n-rw-r--r-- 1 root root 148 Aug 21 16:29 sub_run.py\n-rw-r--r-- 1 root root 257 Aug 21 16:53 test_subprocess1.py\n-rw-r--r-- 1 root root 340 Aug 21 16:52 test_subprocess2.py\n-rw-r--r-- 1 root root 332 Aug 21 17:03 test_subprocess3.py\n-rw-r--r-- 1 root root 183 Aug 21 16:44 test_subprocess.py')
python 之 subprocess
来源: http://www.bubuko.com/infodetail-2272963.html