多进程fork()函数执行的理解

对多进程的理解可以参考
https://blog.csdn.net/hustyangju/article/details/12617991

这里贴一段python代码，帮助理解
import os
a=os.fork()

if a<0:
print ‘error’
elif a==0:
print ‘b processing(%s)parent processing(%s)’ % (os.getpid() ,os.getppid())
else:
print ‘a processing(%s)parent processing(%s)’ % (os.getpid() ,os.getppid())

b=os.fork()
if b<0:
print ‘error’
elif b==0:
print ‘c processing(%s)parent processing(%s)’ % (os.getpid() ,os.getppid())
else:
print ‘e processing(%s)parent processing(%s)’ % (os.getpid() ,os.getppid())

执行结果为
a processing(26773)parent processing(25747)
e processing(26773)parent processing(25747)
b processing(26774)parent processing(26773)
e processing(26774)parent processing(26773)
c processing(26776)parent processing(26774)
c processing(26775)parent processing(26773)