os_kernel_lab/related_info/lab7/ipc/pipe-ex1.py

24 lines
733 B
Python

#!/usr/bin/env python
# -*- encoding: utf8 -*-
import os, sys
print "I'm going to fork now - the child will write something to a pipe, and the parent will read it back"
r, w = os.pipe() # r,w是文件描述符, 不是文件对象
pid = os.fork()
if pid:
# 父进程
os.close(w) # 关闭一个文件描述符
r = os.fdopen(r) # 将r转化为文件对象
print "parent: reading"
txt = r.read()
os.waitpid(pid, 0) # 确保子进程被撤销
else:
# 子进程
os.close(r)
w = os.fdopen(w, 'w')
print "child: writing"
w.write("here's some text from the child")
w.close()
print "child: closing"
sys.exit(0)
print "parent: got it; text =", txt