# supervisorctl > Supervisor is a client/server system that allows its users to control a number of processes on UNIX-like operating systems. > Supervisorctl is the command-line client piece of the supervisor which provides a shell-like interface. > More information: . - Start/stop/restart a process: `supervisorctl {{start|stop|restart}} {{process_name}}` - Start/stop/restart all processes in a group: `supervisorctl {{start|stop|restart}} {{group_name}}:*` - Show last 100 **bytes** of process stderr: `supervisorctl tail -100 {{process_name}} stderr` - Keep displaying stdout of a process: `supervisorctl tail -f {{process_name}} stdout` - Reload process config file to add/remove processes as necessary: `supervisorctl update`