查看进程

ps -aux

序列解释：

进程状态解释

具体解释可参阅man ps

PROCESS STATE CODES
Here are the different values that the s, stat and state output specifiers (header "STAT" or "S") will display to describe the state of a process:

D    uninterruptible sleep (usually IO)
           I    Idle kernel thread 空闲内核线程
           R    running or runnable (on run queue) 运行状态
           S    interruptible sleep (waiting for an event to complete) 休眠状态
           T    stopped by job control signal 暂停
           t    stopped by debugger during the tracing 暂停
           W    paging (not valid since the 2.6.xx kernel)
           X    dead (should never be seen) 死亡进程
           Z    defunct ("zombie") process, terminated but not reaped by its parent 僵尸进程

   For BSD formats and when the stat keyword is used, additional characters may be displayed:

           <    high-priority (not nice to other users) 高优先级
           N    low-priority (nice to other users) 低优先级
           L    has pages locked into memory (for real-time and custom IO)
           s    is a session leader 领导者，其下有子进程
           l    is multi-threaded (using CLONE_THREAD, like NPTL pthreads do)
           +    is in the foreground process group

进程操作

python demo

import time
for i in range(0,9999):
    print(i)
    time.sleep(1)

执行ps -aux | grep python

此时可以看到python3 test.py进程是S+

执行kill -STOP 490142，再次执行ps -aux | grep python

此时可以看到python3 test.py进程是T

而运行的python的标签显示
[1]+ Stopped python3 test.py

执行fg可继续运行进程 fg将后台运行的或挂起的任务（或作业）切换到前台运行

也可以使用kill -CONT 490142继续运行，但是这种运行会恢复控制台的输入，相当于后台运行

用途

比如说某个进程一致存在写库操作，但是发现数据库可能存在一些问题，但是又不方便关闭这个程序，需要验证是否存在问题时，可暂停这个进程，检查完之后在做决定。