Concept
Launchd
Related concepts (7)
Systemd
Systemd is a software suite that provides an array of system components for Linux operating systems. The main aim is to unify service configuration and behavior across Linux distributions. Its primary component is a "system and service manager" – an init system used to bootstrap user space and manage user processes. It also provides replacements for various daemons and utilities, including device management, login management, network connection management, and event logging.
TCP Wrappers
NOTOC TCP Wrappers (also known as tcp_wrappers) is a host-based networking ACL system, used to filter network access to Internet Protocol servers on (Unix-like) operating systems such as Linux or BSD. It allows host or subnetwork IP addresses, names and/or ident query replies, to be used as tokens on which to filter for access control purposes. The original code was written by Wietse Venema in 1990 to monitor a cracker's activities on the Unix workstations at the Department of Math and Computer Science at the Eindhoven University of Technology.
Cron
The cron command-line utility is a job scheduler on Unix-like operating systems. Users who set up and maintain software environments use cron to schedule jobs (commands or shell scripts), also known as cron jobs, to run periodically at fixed times, dates, or intervals. It typically automates system maintenance or administration—though its general-purpose nature makes it useful for things like downloading files from the Internet and downloading email at regular intervals. Cron is most suitable for scheduling repetitive tasks.
Super-server
A super-server or sometimes called a service dispatcher is a type of daemon run generally on Unix-like systems. A super-server starts other servers when needed, normally with access to them checked by a TCP wrapper. It uses very few resources when in idle state. This can be ideal for workstations used for local web development, client/server development or low-traffic daemons with occasional usage (such as ident and SSH). The creation of an operating system process embodying the sub-daemon is deferred until an incoming connection for the sub-daemon arrives.
Inetd
inetd (internet service daemon) is a super-server daemon on many Unix systems that provides Internet services. For each configured service, it listens for requests from connecting clients. Requests are served by spawning a process which runs the appropriate executable, but simple services such as echo are served by inetd itself. External executables, which are run on request, can be single- or multi-threaded. First appearing in 4.3BSD, it is generally located at /usr/sbin/inetd.
Init
In Unix-based computer operating systems, init (short for initialization) is the first process started during booting of the operating system. Init is a daemon process that continues running until the system is shut down. It is the direct or indirect ancestor of all other processes and automatically adopts all orphaned processes. Init is started by the kernel during the booting process; a kernel panic will occur if the kernel is unable to start it, or it should die for any reason. Init is typically assigned process identifier 1.
Daemon (computing)
In multitasking computer operating systems, a daemon (ˈdiːmən or ˈdeɪmən) is a computer program that runs as a background process, rather than being under the direct control of an interactive user. Traditionally, the process names of a daemon end with the letter d, for clarification that the process is in fact a daemon, and for differentiation between a daemon and a normal computer program. For example, is a daemon that implements system logging facility, and is a daemon that serves incoming SSH connections.