A. Foreground Processes:
You can use the keyboard to issue a signal on your current processing by pressing a keyboard control sequence t
1. Suspend foreground process
# Ctrl+z
2. Kill foreground process
# Ctrl+c
3. Core Dump
# Ctrl+\
B. Background Process
- Check the list of kill option
# kill -l 1) SIGHUP 2) SIGINT 3) SIGQUIT 4) SIGILL 5) SIGTRAP 6) SIGABRT 7) SIGBUS 8) SIGFPE 9) SIGKILL 10) SIGUSR1 11) SIGSEGV 12) SIGUSR2 13) SIGPIPE 14) SIGALRM 15) SIGTERM 16) SIGSTKFLT 17) SIGCHLD 18) SIGCONT 19) SIGSTOP 20) SIGTSTP ..................................
# kill -9 PID
2. Look up processes based on name and kill them
# pgrep -l -u user1 7000 bash 7001 sleep ...............
# pkill -SIGKILL -u user1
Notes: SIGTERM is the default signal, SIGKILL is a commonly misused administrator favorite. Since the SIGKILL signal cannot be handled or ignored, it is always fatal. However, it forces termination without allowing the killed process to run self-cleanup routines. It is recommended to send SIGTERM first, then retry with SIGKILL only if a process fails to respond
3. kill processes running in tty3
# pkill -SIGKILL -t tty3
4. Use the pstree command to view a process tree for the system or a single user.
# pstree -p root [root@lime ~]# pstree -p root init(1)─┬─NetworkManager(1785) ├─abrtd(2232)