Sobes.tech
Junior

What processes can the long killer utility terminate?

sobes.tech AI

Answer from AI

The utility long killer (presumably referring to pkill) can terminate processes based on various criteria:

  • By process name: Terminate all processes with a given name.

    # Terminate all processes named "nginx"
    pkill nginx
    
  • By user UID: Terminate all processes belonging to a specific user.

    # Terminate all processes of user "user1"
    pkill -U user1
    
  • By group GUID: Terminate all processes belonging to a specific group.

    # Terminate all processes of group "developers"
    pkill -G developers
    
  • By signal: Send a specific signal to a process. By default, SIGTERM is sent.

    # Send SIGKILL (9) signal to process named "my_app"
    pkill -9 my_app
    
  • By process ID (PID): Although pkill is mainly used for terminating processes by other criteria, it can also be used with PID, although traditionally kill is used for this.

    # Terminate process with PID 12345
    pkill 12345
    
  • By regular expression pattern: Terminate processes whose names match a given regex.

    # Terminate processes whose names start with "java"
    pkill ^java
    
  • By terminal: Terminate all processes associated with a specific terminal.

    # Terminate all processes on terminal ttyS0
    pkill -t ttyS0
    
  • By launch time: Terminate processes launched more or less recently.

    # Terminate processes launched more than 1 hour ago
    pkill -o 1h
    # Terminate processes launched less than 5 minutes ago
    pkill -n 5m
    

It is important to note that pkill is a more flexible utility compared to killall, as it supports regular expressions.