What does the "<>" mean in "kill -9 <>"?

I am going through a tutorial on recovering from a database failure and in the tutorial, a failure on the host of the primary database is simulated with:

kill -9 <>

I know that the kill command is used to send a signal to a process, and that 9 represents the SIGKILL signal that terminates a process, but what does the <> argument stand for?

I have read the manual pages for the kill command but still cannot figure out why and what for <> is used.

Solution 1:

You're supposed to replace the <> by the process id. To get the process id, you can use the command

ps -aux

It will list all the processes, and you just have to choose the right process

If you have a single instance of a process, you can also use the pkill commmand with the name of the process, eg

pkill -9 mysql

Solution 2:

It is

<pid> [...]
      Send signal to every <pid> listed.

in manpage. There is always description inside of the <> quotes.

Solution 3:

<> in the man page means replace <> with PID.

In addition to the answer by Felicien using the ps command, you can also use top or htop

top -d 10

Use -d <> (duration) to update every <> seconds.

To kill the process, simply note the PID and kill the process ID with:

kill -9 xxxx

Note: for htop, you will need to type htop -d 100 ie; 10 seconds.