Python os.pipe() Method

Python File(文件) 方法 Python OS File/Directory Methods

Overview

The os.pipe() method is used to create a pipe, returning a pair of file descriptors (r, w) for reading and writing respectively.

Syntax

pipe()The method syntax is as follows:

os.pipe()

Parameters

None

Return Value

Returns a pair of file descriptors.

Example

The following example demonstrates the use of the pipe() method:

#!/usr/bin/python
# -*- coding: UTF-8 -*-

import os, sys

print "The child will write text to a pipe and "
print "the parent will read the text written by child..."

# file descriptors r, w for reading and writing
r, w = os.pipe() 

processid = os.fork()
if processid:
    # This is the parent process 
    # Closes file descriptor w
    os.close(w)
    r = os.fdopen(r)
    print "Parent reading"
    str = r.read()
    print "text =", str   
    sys.exit(0)
else:
    # This is the child process
    os.close(r)
    w = os.fdopen(w, 'w')
    print "Child writing"
    w.write("Text written by child...")
    w.close()
    print "Child closing"
    sys.exit(0)

The output of the above program is:

The child will write text to a pipe and
the parent will read the text written by child...
Parent reading
Child writing
Child closing
text = Text written by child...