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10个基本的linux ps 命令例子


Linux ps command

The ps command on linux is one of the most basic commands for viewing the processes running on the system. It provides a snapshot of the current processes along with detailed information like user id, cpu usage, memory usage, command name etc. It does not display data in real time like top or htop commands. But even though being simpler in features and output it is still an essential process management/monitoring tool that every linux newbie should know about and learn well.


In this post we are going to revise the basics of using the ps command to check the processes and filter and sort them in different ways to suit better.


Note on syntax


The ps command comes with an unusual set of 2 syntax styles. That is BSD and UNIX both. New users are often confused with and mis-interpret the two styles. So here is some basic info to get it clear before moving on.


注意: ps aux 和ps -aux 并不相同,举例来说 -u 是显示进程的拥有着,但是u 表示显示详细信息

BSD style – The options in bsd style syntax are not preceded with a dash.

BSD: 就是后边没有-,直接跟选项

UNIX/LINUX style – The options in linux style syntax are preceded by a dash as usual.

UNIX/LINUX:就是后边跟着 – 然后跟选项

How to use ps command

1. Display all processes


The following command will give a full list of processes


Pipe the output to “less” to make it scrollable.

使用 管道链接 less命令后我们可以使用滚动条来查看具体信息

Use the “u” option or “-f” option to display detailed information about the processes

使用u 或者-f 来显示详细信息

2. Display process by user


To filter the processes by the owning user use the “-u” option followed by the username. Multiple usernames can be provided separated by a comma.

来单独显示某用户拥有的进程 -u “username”,可以输入过个用户名,通过”,”分割

3. Show process by name or process id


To search the processes by their name or command use the “-C” option followed by the search term.

我们可以通过-C 来查找具体名称的进程

To display processes by process id, use the “-p” option and provides the process ids separated by comma.

可以通过-p 选项来显示具体id大进程信息,也可以通过“,”来一次传入多个

The “-C” must be provided with the exact process name and it cannot actually search with a partial name or wildcard. To search the process list more flexibly, the usual grep command has to be used

-C 选项要求我们要输入完全匹配的进程名称,所以我们更倾向于使用grep来进行筛选

4. Sort process by cpu or memory usage


System administrators often want to find out processes that are consuming lots of memory or CPU. The sort option will sort the process list based on a particular field or parameter.


Multiple fields can be specified with the “–sort” option separated by a comma. Additionally the fields can be prefixed with a “-” or “+” symbol indicating descending or ascending sort respectively. There are lots of parameters on which the process list can be sorted. Check the man page for the complete list.

多个参数的时候我们可以使用 –sort来进行排序,通过“,”来输入,我们可以在排序的参数前边家“-”或者“+”,表示整序或者倒序进行排序,更多的选项可以通过man手册来查找

Display the top 5 processes consuming most of the cpu.


5. Display process hierarchy in a tree style


Many processes are actually forked out of some parent process, and knowing this parent child relationship is often helpful. The ‘–forest’ option will construct an ascii art style tree view of the process hierarchy.

许多进程其实通过许多父进程fork出来的,并且很多时候知道这些父子关系很又用, –forest 可以实现这个目的

The following command will search for processes by the name apache2 and construct a tree and display detailed information.


6. Display child processes of a parent process


Here is an example of finding all forked apache processes.


The first process that is owned by root is the main apache2 process and all other apache2 processes have been forked out of this main process. The next command lists all child apache2 processes using the pid of the main apache2 process


7. Display threads of a process


The “-L” option will display the threads along with the processes. It can be used to display all threads of a particular process or all processes.


The following command shall display all the threads owned by the process with id 3150.


8. Change the columns to display


The ps command can be configured to show a selected list of columns only. There are a large number of columns to to show and the full list is available in the man pages.

ps命令可以指定我们要显示的数据栏,ps有很多栏目可以显示,具体的可以参考man 手册

The following command shows only the pid, username, cpu, memory and command columns.

下面的命令只会显示 pid ,username,cpu,memory ,和comm

It is possible to rename the column labels


Quite flexible.

9. Display elapsed time of processes


The elapsed time indicates, how long the process has been running for. The column for elapsed time is not shown by default, and has to be brought in using the “-o” option


10. Turn ps into an realtime process viewer


As usual, the watch command can be used to turn ps into a realtime process reporter. Simple example is like this


The output on my desktop is something like this.


The output would be updated every 1 second to refresh the stats. However do not think that this is similar to top.

You would notice that the output of top/htop command changes much more frequently compared to the above ps command.
This is because the top output sorts on a value that is a mix of cpu usage and memory usage. But the above ps command sorts in a more simpler manner, taking 1 column at a time (like school maths). So it would not update rapidly like top.

你会发现 top/htop命令的刷新频率比ps的高很多