document/TranslateProject
2
0
Fork 0
mirror of https://github.com/LCTT/TranslateProject.git synced 2025-02-03 23:40:14 +08:00
Code Issues Packages Projects Releases Wiki Activity

[Translated] 10 basic examples of Linux ps command

Browse Source
This commit is contained in:
geekpi 2013-12-04 02:47:37 +00:00
parent 1731b20653
commit 5b4cfbb7fc
2 changed files with 216 additions and 218 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

218
sources/10 basic examples of Linux ps command.md
View File

@ -1,218 +0,0 @@
translating-----------------geekpi
10 basic examples of Linux ps command
================================================================================
### 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.
> Note : "ps aux" is not the same as "ps -aux". For example "-u" is used to show process of that user. But "u" means show detailed information.
BSD style - The options in bsd style syntax are not preceded with a dash.
ps aux
UNIX/LINUX style - The options in linux style syntax are preceded by a dash as usual.
ps -ef
It is okay to mix both the syntax styles on linux systems. For example "ps ax -f".
But in this post we shall mostly focus on the unix style syntax.
### How to use ps command ###
#### 1. Display all processes ####
The following command will give a full list of processes
$ ps ax
$ ps -ef
Pipe the output to "less" to make it scrollable.
Use the "u" option or "-f" option to display detailed information about the processes
$ ps aux
$ ps -ef -f
> Why is the USER column not displaying my username, but showing others like root, www-data etc ?
For all usernames (including yours) if the length is greater than 8 characters then ps will fall back to show only the UID instead of username.
#### 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.
$ ps -f -u www-data
UID PID PPID C STIME TTY TIME CMD
www-data 1329 1328 0 09:32 ? 00:00:00 nginx: worker process
www-data 1330 1328 0 09:32 ? 00:00:00 nginx: worker process
www-data 1332 1328 0 09:32 ? 00:00:00 nginx: worker process
www-data 1377 1372 0 09:32 ? 00:00:00 php-fpm: pool a.localhost
www-data 1378 1372 0 09:32 ? 00:00:00 php-fpm: pool a.localhost
www-data 4524 2359 0 10:03 ? 00:00:00 /usr/sbin/apache2 -k start
www-data 4527 2359 0 10:03 ? 00:00:00 /usr/sbin/apache2 -k start
www-data 4528 2359 0 10:03 ? 00:00:00 /usr/sbin/apache2 -k start
#### 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.
$ ps -C apache2
PID TTY TIME CMD
2359 ? 00:00:00 apache2
4524 ? 00:00:00 apache2
4525 ? 00:00:00 apache2
...
To display processes by process id, use the "-p" option and provides the process ids separated by comma.
$ ps -f -p 3150,7298,6544
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
$ ps -ef | grep apache
#### 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.
$ ps aux --sort=-pcpu,+pmem
Display the top 5 processes consuming most of the cpu.
$ ps aux --sort=-pcpu | head -5
USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND
root 1 2.6 0.7 51396 7644 ? Ss 02:02 0:03 /usr/lib/systemd/systemd --switched-root --system --deserialize 23
root 1249 2.6 3.0 355800 30896 tty1 Rsl+ 02:02 0:02 /usr/bin/X -background none :0 vt01 -nolisten tcp
root 508 2.4 1.6 248488 16776 ? Ss 02:02 0:03 /usr/bin/python /usr/sbin/firewalld --nofork
silver 1525 2.1 2.3 448568 24392 ? S 02:03 0:01 /usr/bin/python /usr/share/system-config-printer/applet.py
#### 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.
The following command will search for processes by the name apache2 and construct a tree and display detailed information.
$ ps -f --forest -C apache2
UID PID PPID C STIME TTY TIME CMD
root 2359 1 0 09:32 ? 00:00:00 /usr/sbin/apache2 -k start
www-data 4524 2359 0 10:03 ? 00:00:00 \_ /usr/sbin/apache2 -k start
www-data 4525 2359 0 10:03 ? 00:00:00 \_ /usr/sbin/apache2 -k start
www-data 4526 2359 0 10:03 ? 00:00:00 \_ /usr/sbin/apache2 -k start
www-data 4527 2359 0 10:03 ? 00:00:00 \_ /usr/sbin/apache2 -k start
www-data 4528 2359 0 10:03 ? 00:00:00 \_ /usr/sbin/apache2 -k start
> Try not to use any sorting with the tree style display, as they both effect the order of display in different ways.
#### 6. Display child processes of a parent process ####
Here is an example of finding all forked apache processes.
$ ps -o pid,uname,comm -C apache2
PID USER COMMAND
2359 root apache2
4524 www-data apache2
4525 www-data apache2
4526 www-data apache2
4527 www-data apache2
4528 www-data apache2
[term]
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
[term]
$ ps --ppid 2359
PID TTY TIME CMD
4524 ? 00:00:00 apache2
4525 ? 00:00:00 apache2
4526 ? 00:00:00 apache2
4527 ? 00:00:00 apache2
4528 ? 00:00:00 apache2
#### 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.
$ ps -p 3150 -L
#### 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.
The following command shows only the pid, username, cpu, memory and command columns.
$ ps -e -o pid,uname,pcpu,pmem,comm
It is possible to rename the column labels
$ ps -e -o pid,uname=USERNAME,pcpu=CPU_USAGE,pmem,comm
PID USERNAME CPU_USAGE %MEM COMMAND
1 root 0.0 0.0 init
2 root 0.0 0.0 kthreadd
3 root 0.0 0.0 ksoftirqd/0
4 root 0.0 0.0 kworker/0:0
5 root 0.0 0.0 kworker/0:0H
7 root 0.0 0.0 migration/0
8 root 0.0 0.0 rcu_bh
9 root 0.0 0.0 rcuob/0
10 root 0.0 0.0 rcuob/1
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
$ ps -e -o pid,comm,etime
#### 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
$ watch -n 1 'ps -e -o pid,uname,cmd,pmem,pcpu --sort=-pmem,-pcpu | head -15'
The output on my desktop is something like this.
Every 1.0s: ps -e -o pid,uname,cmd,pmem,pcpu --... Sun Dec 1 18:16:08 2013
PID USER CMD %MEM %CPU
3800 1000 /opt/google/chrome/chrome - 4.6 1.4
7492 1000 /opt/google/chrome/chrome - 2.7 1.4
3150 1000 /opt/google/chrome/chrome 2.7 2.5
3824 1000 /opt/google/chrome/chrome - 2.6 0.6
3936 1000 /opt/google/chrome/chrome - 2.4 1.6
2936 1000 /usr/bin/plasma-desktop 2.3 0.2
9666 1000 /opt/google/chrome/chrome - 2.1 0.8
3842 1000 /opt/google/chrome/chrome - 2.1 0.8
4739 1000 /opt/google/chrome/chrome - 1.8 1.0
3930 1000 /opt/google/chrome/chrome - 1.7 1.0
3911 1000 /opt/google/chrome/chrome - 1.6 0.6
3645 1000 /opt/google/chrome/chrome - 1.5 0.4
3677 1000 /opt/google/chrome/chrome - 1.5 0.4
3639 1000 /opt/google/chrome/chrome - 1.4 0.4
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.
--------------------------------------------------------------------------------
via: http://www.binarytides.com/linux-ps-command/
译者：[译者ID](https://github.com/译者ID) 校对：[校对者ID](https://github.com/校对者ID)
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译，[Linux中国](http://linux.cn/) 荣誉推出

216
translated/10 basic examples of Linux ps command.md Executable file
View File

@ -0,0 +1,216 @@
ps命令的10个例子
================================================================================
### Linux ps 命令 ###
linux的ps命令是一个浏览系统运行的进程的一个最基础的工具。它提供了一个当前进程的快照，还带有一些具体的信息，比如用户id，cpu使用率，内存使用，命令名等它不会像top或者htop一样实时显示数据。即使他在功能和输出上更见但，但是它仍是一个每个linux新人需要了解和学习的一个必要的进程管理/检测工具。
在本篇中，我门会复习ps命令基本的用法:检测、过滤、以不同的方式排序进程来更好地适应。
### 语法说明 ###
ps命令有两种不同风格的语法规则。它们是BSD和UNIX。新人经常感到困惑并会误解这两种风格。因此在继续本篇之前有一些基本的信息要澄清。
> 注意: "ps aux"不等同于"ps -aux"。比如"-u"用于显示用户的进程，但是"u"意味着显示具体信息。
BSD 形式 - BSD形式的语法的选项前没有破折号。
ps aux
UNIX/LINUX 形式 - linux形式的语法的选项前有破折号。
ps -ef
在linux系统上混合这两种语法是可以的。比如 "ps ax -f"。但是本章中我们主要讨论unix形式语法。
### 如何使用ps命令 ###
#### 1. 显示所有进程 ####
下面的命令可以显示所有进程的列表。
$ ps ax
$ ps -ef
通过管道输出到"less"可以使它滚动。
使用"u"或者"-f"选项可以显示进程的具体信息。
$ ps aux
$ ps -ef -f
> 为什么USER列显示的不是我的用户名而是其他的像root，www-data等等？
对于所有的用户(包括你们的)，如果长度大于8个字符，那么ps只会显示你的UID而不是用户名。
#### 2. 显示用户进程 ####
使用"-u"选项后跟用户名来过滤所属用户的进程。多个用户名可以用逗号分隔。
$ ps -f -u www-data
UID PID PPID C STIME TTY TIME CMD
www-data 1329 1328 0 09:32 ? 00:00:00 nginx: worker process
www-data 1330 1328 0 09:32 ? 00:00:00 nginx: worker process
www-data 1332 1328 0 09:32 ? 00:00:00 nginx: worker process
www-data 1377 1372 0 09:32 ? 00:00:00 php-fpm: pool a.localhost
www-data 1378 1372 0 09:32 ? 00:00:00 php-fpm: pool a.localhost
www-data 4524 2359 0 10:03 ? 00:00:00 /usr/sbin/apache2 -k start
www-data 4527 2359 0 10:03 ? 00:00:00 /usr/sbin/apache2 -k start
www-data 4528 2359 0 10:03 ? 00:00:00 /usr/sbin/apache2 -k start
#### 3. 通过名字或者进程id显示进程 ####
通过"-C"选项后面加上名字或者命令来搜索进程。
$ ps -C apache2
PID TTY TIME CMD
2359 ? 00:00:00 apache2
4524 ? 00:00:00 apache2
4525 ? 00:00:00 apache2
...
要通过进程id显示进程，就使用"-p"选项，并且它还提供使用逗号来分割进程id。
$ ps -f -p 3150,7298,6544
"-C"必须提供精确的进程名，并且它并不能通过部分名字或者通配符查找。为了更弹性地搜索进程列表，通常使用grep命令。
$ ps -ef | grep apache
#### 4. 通过cpu或者内存使用排序进程 ####
系统管理员通常想要找出那些消耗最多内存或者CPU的进程。排序选项会基于特性的字段或者参数排序进程列表。
多个字段可以用'--sort'指定，并用逗号分割。除此之外，字段前面还可以跟上'-'或者'+'的前缀来相应地表示递减和递增排序。这里有很多的用于排序的选项。通过man页来获取完整的列表。
$ ps aux --sort=-pcpu,+pmem
显示前5名最耗cpu的进程。
$ ps aux --sort=-pcpu | head -5
USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND
root 1 2.6 0.7 51396 7644 ? Ss 02:02 0:03 /usr/lib/systemd/systemd --switched-root --system --deserialize 23
root 1249 2.6 3.0 355800 30896 tty1 Rsl+ 02:02 0:02 /usr/bin/X -background none :0 vt01 -nolisten tcp
root 508 2.4 1.6 248488 16776 ? Ss 02:02 0:03 /usr/bin/python /usr/sbin/firewalld --nofork
silver 1525 2.1 2.3 448568 24392 ? S 02:03 0:01 /usr/bin/python /usr/share/system-config-printer/applet.py
#### 5. 以树的形式显示进程层级 ####
许多进程实际上是从同一个父进程fork出来的，并且了解父子关系通常是很有用的。"--forest" 选项会构造一个ascii艺术形式的进程层级视图。
下面的命令会用apache2的进程名来搜索并构造一个树来显示具体信息。
$ ps -f --forest -C apache2
UID PID PPID C STIME TTY TIME CMD
root 2359 1 0 09:32 ? 00:00:00 /usr/sbin/apache2 -k start
www-data 4524 2359 0 10:03 ? 00:00:00 \_ /usr/sbin/apache2 -k start
www-data 4525 2359 0 10:03 ? 00:00:00 \_ /usr/sbin/apache2 -k start
www-data 4526 2359 0 10:03 ? 00:00:00 \_ /usr/sbin/apache2 -k start
www-data 4527 2359 0 10:03 ? 00:00:00 \_ /usr/sbin/apache2 -k start
www-data 4528 2359 0 10:03 ? 00:00:00 \_ /usr/sbin/apache2 -k start
> 尽量不要在排序中使用树状显示，因为两者都会以不同方式影响显示的顺序。
#### 6. 显示父进程的子进程 ####
下面一个是找出所有从apache进程fork出来的进程的例子。
$ ps -o pid,uname,comm -C apache2
PID USER COMMAND
2359 root apache2
4524 www-data apache2
4525 www-data apache2
4526 www-data apache2
4527 www-data apache2
4528 www-data apache2
[term]
第一个属于root的进程是apache2的主进程，其他的apache进程都是从主进程fork出来的。下面的命令使用apache2主进程的pid列出了所有的apache2的子进程。
[term]
$ ps --ppid 2359
PID TTY TIME CMD
4524 ? 00:00:00 apache2
4525 ? 00:00:00 apache2
4526 ? 00:00:00 apache2
4527 ? 00:00:00 apache2
4528 ? 00:00:00 apache2
#### 7. 显示进程的线程 ####
"-L"选项会随着进程一起显示线程。它可用于显示所有特定进程或者所有进程的线程。
下面的命令会显示进程id为3150的进程的所有线程。
$ ps -p 3150 -L
#### 8. 改变显示的列 ####
ps命令可以被配置用来只显示被选中的列。很多列可以被用来显示，并且完整的列表在man页中。
下面的命令会只显示pid、用户名、cpu、内存、命令列。
$ ps -e -o pid,uname,pcpu,pmem,comm
同样可以重命名列的名字。
$ ps -e -o pid,uname=USERNAME,pcpu=CPU_USAGE,pmem,comm
PID USERNAME CPU_USAGE %MEM COMMAND
1 root 0.0 0.0 init
2 root 0.0 0.0 kthreadd
3 root 0.0 0.0 ksoftirqd/0
4 root 0.0 0.0 kworker/0:0
5 root 0.0 0.0 kworker/0:0H
7 root 0.0 0.0 migration/0
8 root 0.0 0.0 rcu_bh
9 root 0.0 0.0 rcuob/0
10 root 0.0 0.0 rcuob/1
非常弹性化。
#### 9. 显示进程运行的时间 ####
运行的时间指的是，进程已经运行的时间。运行时间的列并没有默认显示，需要使用-o选项带入。
$ ps -e -o pid,comm,etime
#### 10. 将ps转换为实时进程查看器 ####
As usual, the watch command can be used to turn ps into a realtime process reporter. Simple example is like this
通常上，watch命令可将ps命令变成实时进程查看器。像这个简单的命令
$ watch -n 1 'ps -e -o pid,uname,cmd,pmem,pcpu --sort=-pmem,-pcpu | head -15'
我桌面上的输出就像这样。
Every 1.0s: ps -e -o pid,uname,cmd,pmem,pcpu --... Sun Dec 1 18:16:08 2013
PID USER CMD %MEM %CPU
3800 1000 /opt/google/chrome/chrome - 4.6 1.4
7492 1000 /opt/google/chrome/chrome - 2.7 1.4
3150 1000 /opt/google/chrome/chrome 2.7 2.5
3824 1000 /opt/google/chrome/chrome - 2.6 0.6
3936 1000 /opt/google/chrome/chrome - 2.4 1.6
2936 1000 /usr/bin/plasma-desktop 2.3 0.2
9666 1000 /opt/google/chrome/chrome - 2.1 0.8
3842 1000 /opt/google/chrome/chrome - 2.1 0.8
4739 1000 /opt/google/chrome/chrome - 1.8 1.0
3930 1000 /opt/google/chrome/chrome - 1.7 1.0
3911 1000 /opt/google/chrome/chrome - 1.6 0.6
3645 1000 /opt/google/chrome/chrome - 1.5 0.4
3677 1000 /opt/google/chrome/chrome - 1.5 0.4
3639 1000 /opt/google/chrome/chrome - 1.4 0.4
输出会每秒刷新状态。但不要认为这和top相似。
你会发现top/htop命令的输出相比上面的ps命令刷新得更频繁。
这是因为top输出会cpu使用和内存使用值混合排序后的输出。但是上面的ps命令是一个更简单的行为的排序，每次获取一列(像学校的数学)。因此它不会像top那样快速更新。
--------------------------------------------------------------------------------
via: http://www.binarytides.com/linux-ps-command/
译者：[geekpi](https://github.com/geekpi) 校对：[校对者ID](https://github.com/校对者ID)
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译，[Linux中国](http://linux.cn/) 荣誉推出