[Comprehensive explanation of Linux commands] 164. In-depth understanding of the ps command in Linux: Process status reporting tool

ps command

Additional information

psThe command is used to report the process status of the current system. You can use killcommands to interrupt and delete unnecessary programs at any time. psThe command is the most basic but also very powerful process viewing command. You can use this command to determine which processes are running and running status, whether the process has ended, whether the process is zombie, which processes occupy too many resources, etc. In short, Some information can be obtained by executing this command.

grammar

ps(选项)

Options

• -a: Displays the programs executed under all terminals, except the stage job leader.
• a: Display all programs under the current terminal, including programs of other users.
• -A: Display all programs.
• -c: Display CLS and PRI fields.
• c: When listing programs, display the actual command name of each program without including the path, options, or identification of resident services.
• -C<指令名称>: Specify the name of the execution instruction and list the status of the program that executes the instruction.
• -d: Shows all programs except the program of the stage job leader.
• -e: This option has the same effect as specifying the "A" option.
• e: When listing programs, display the environment variables used by each program.
• -f: Display UID, PPIP, C and STIME fields.
• f: Use ASCII characters to display a tree structure and express the relationship between programs.
• -g<群组名称>: This option has the same effect as specifying the "-G" option, and can also be specified using the name of the stage job leader.
• g: Display all programs under the current terminal, including the group leader's programs.
• -G<群组识别码>: Lists the status of programs belonging to this group, which can also be specified using the group name.
• h: Does not display the title bar.
• H: Displays a tree structure, indicating the relationship between programs.
• jOr j: Display program status in job control format.
• lOr l: Use a detailed format to display program status.
• L: List the relevant information of the field.
• mOr m: display all execution threads.
• n: Use numbers to represent USER and WCHAN fields.
• N: Display all programs, except programs under the terminal that execute the ps command.
• -p<程序识别码>: Specify the program identification code and list the status of the program.
• p<程序识别码>: The effect of this option is the same as specifying the "-p" option, with only slight differences in the list format.
• r: List only the programs currently being executed by the terminal.
• -s<阶段作业>: Specify the program identification code of the stage operation, and list the status of the programs belonging to the stage operation.
• s: Use the program signal format to display the program status.
• S: When listing programs, include interrupted subroutine information.
• -t<终端机编号>: Specify a terminal number and list the status of programs belonging to that terminal.
• t<终端机编号>: The effect of this option is the same as specifying the "-t" option, with only slight differences in the list format.
• T: Display all programs under the current terminal.
• -u<用户识别码>: This option has the same effect as specifying the "-U" option.
• u: Display program status in user-oriented format.
• -U<用户识别码>: Lists the status of programs belonging to this user, which can also be specified using the user name.
• U<用户名称>: Lists the status of programs belonging to this user.
• v: Display program status in virtual memory format.
• VOr V: Display version information.
• wOr w: Use a broad format to display program status.
• x: Display all programs, not distinguished by terminal.
• X: Use the old Linux i386 login format to display program status.
• -y: When used with the option "-l", the F (flag) field is not displayed and the ADDR field is replaced by the RSS field.
• -<程序识别码>: This option has the same effect as specifying the "p" option.
• --cols<每列字符数>: Set the maximum number of characters per column.
• --columns<每列字符数>: This option has the same effect as specifying the "--cols" option.
• --cumulative: This option has the same effect as specifying the "S" option.
• --deselect: This option has the same effect as specifying the "-N" option.
• --forest: This option has the same effect as specifying the "f" option.
• --headers: Display the title bar repeatedly.
• --help: Online help.
• --info: Display troubleshooting information.
• --lines<显示列数>: Set the number of columns in the display screen.
• --no-headers: The effect of this option is the same as specifying the "h" option, with only slight differences in the list format.
• --group<群组名称>: This option has the same effect as specifying the "-G" option.
• --Group<群组识别码>: This option has the same effect as specifying the "-G" option.
• --pid<程序识别码>: This option has the same effect as specifying the "-p" option.
• --rows<显示列数>: This option has the same effect as specifying the "-lines" option.
• --sid<阶段作业>: This option has the same effect as specifying the "-s" option.
• --tty<终端机编号>: This option has the same effect as specifying the "-t" option.
• --user<用户名称>: This option has the same effect as specifying the "-U" option.
• --User<用户识别码>: This option has the same effect as specifying the "-U" option.
• --version: This option has the same effect as specifying the "-V" option.
• --widty<每列字符数>: This option has the same effect as specifying the "-cols" option.

Example

• View the PID, name and CPU usage of the process:

  ps axo pid,comm,pcpu
  

• Sort processes by memory resource usage:

  ps aux | sort -rnk 4
  

• Sort processes by CPU resource usage:

  ps aux | sort -nk 3
  

• Display all process information:

  ps -A
  

• Display specified user information:

  ps -u root
  

• Check the number of threads:

  ps -efL
  

• View processes and sort them by memory usage:

  ps -e -o "%C : %p :%z : %a" | sort -k5 -nr
  

• Display all process information, along with the command line:

  ps -ef
  

• Commonly used combinations of ps and grep to find specific processes:

  ps -ef | grep ssh
  

• Search for processes by name or command:

  ps -C nginx
  

• CPU or memory sorting, descending order:

  ps aux --sort=-pcpu,+pmem
  

• Display the hierarchical relationship of processes in a tree style:

  ps -f --forest -C nginx
  

• Display the child processes of a parent process:

  ps -o pid,uname,comm -C nginx
  

• Redefine tags:

  ps -e -o pid,uname=USERNAME,pcpu=CPU_USAGE,pmem,comm
  

• Show how long a process has been running:

  ps -e -o pid,comm,etime
  

• View named process details:

  ps -aux | grep named
  

• Get the service name by process id:

  ps -o command -p 91730 | sed -n 2p
  

• List the PID and related information currently belonging to you for this login:

  ps -l
  

• List all programs currently in memory:

  ps aux
  

• Find out the PID numbers associated cronwith syslogthese two services:

  ps aux | egrep '(cron|syslog)'
  

• Display all processes and output to ps001.txta file:

  ps -aux > ps001.txt
  

• Output the specified fields:

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