Python os.pipe2()方法

管道是将信息从一个进程传递到另一个进程的方法。它只提供单向通信，传递的信息由系统保存，直到接收进程读取。
Python中的os.pipe2()方法用于创建一个自动设置标志的管道。

os.pipe2 语法

os.pipe2(flags)

os.pipe2 参数

flags: flags参数由一个或多个os.O_NONBLOCK和os.O_CLOEXEC值组合而成。

返回类型:该方法返回一对文件描述符(r, w)，分别用于读取和写入。

os.pipe2 示例1

使用os.pipe2()方法来创建一个自动设置标志的管道

# Python program to explain os.pipe2() method 
  
# importing os module 
import os
  
  
# Create a pipe with
# flag set automatically
# os.O_NONBLOCK flag tells 
# that file descriptor 
# is in non-blocking mode
flags = os.O_NONBLOCK
r, w = os.pipe2(flags)
  
# The returned file descriptor r and w
# can be used for reading and
# writing respectively.
  
# We will create a child process
# and using these file descriptor
# the parent process will write 
# some text and child process will
# read the text written by the parent process
  
# Create a child process
pid = os.fork()
  
# pid greater than 0 represents
# the parent process
if pid > 0:
  
    # This is the parent process 
    # Closes file descriptor r
    os.close(r)
  
    # Write some text to file descriptor w 
    print("Parent process is writing")
    text = b"Hello child process"
    os.write(w, text)
    print("Written text:", text.decode())
  
      
else:
  
    # This is the child process 
    # Closes file descriptor w
    os.close(w)
  
    # Read the text written by parent process
    print("\nChild Process is reading")
    r = os.fdopen(r)
    print("Read text:", r.read())

输出:

Parent process is writing
Text written: Hello child process

Child Process is reading
Text read: Hello child process