Process and thread

job and process almost interchangeable

一个作业=一个进程

process execution must progress in sequential fashion

进程的执行必须是顺序方式的

a process consists of

• program counter 程序计数器
• stack 栈
• data section 数据段

编写一个shell script

P-C processes

Parents processes creates children processes

Resource sharing资源共享

Process termination

• Normal exit
• Error exit
• Fatal Error
• Killed by another process