daemon


Also found in: Dictionary, Thesaurus, Medical, Legal, Financial, Acronyms, Wikipedia.

daemon

[′dē·mən]
(computer science)
In Unix, a program that runs in the background, such as a server.

daemon

(operating system)
/day'mn/ or /dee'mn/ (From the mythological meaning, later rationalised as the acronym "Disk And Execution MONitor") A program that is not invoked explicitly, but lies dormant waiting for some condition(s) to occur. The idea is that the perpetrator of the condition need not be aware that a daemon is lurking (though often a program will commit an action only because it knows that it will implicitly invoke a daemon).

For example, under ITS writing a file on the LPT spooler's directory would invoke the spooling daemon, which would then print the file. The advantage is that programs wanting files printed need neither compete for access to, nor understand any idiosyncrasies of, the LPT. They simply enter their implicit requests and let the daemon decide what to do with them. Daemons are usually spawned automatically by the system, and may either live forever or be regenerated at intervals.

Unix systems run many daemons, chiefly to handle requests for services from other hosts on a network. Most of these are now started as required by a single real daemon, inetd, rather than running continuously. Examples are cron (local timed command execution), rshd (remote command execution), rlogind and telnetd (remote login), ftpd, nfsd (file transfer), lpd (printing).

Daemon and demon are often used interchangeably, but seem to have distinct connotations (see demon). The term "daemon" was introduced to computing by CTSS people (who pronounced it /dee'mon/) and used it to refer to what ITS called a dragon.

daemon

Pronounced "dee-mun" as in the word for devil, as well as "day-mun," a daemon is a Unix/Linux program that executes in the background ready to perform an operation when required. Functioning like an extension to the operating system, a daemon is usually an unattended process that is initiated at startup. Typical daemons are print spoolers and e-mail handlers or a scheduler that starts up another process at a designated time. The term comes from Greek mythology, meaning "guardian spirit." See agent and mailer-daemon.
References in periodicals archive ?
EST, daemons and supervisors at the NSA had identified and put down more than 80 new distributions of the original files, each of them using a new name to describe the contents and changing compression or file length to change the file signatures in an attempt to confuse automated censors.
He instructs Lyra to keep the alethiometer secret, especially from Mrs Coulter and her golden monkey daemon.
Basically, you need to create a CGI program (or have one created for you) that the Web daemon will execute to transmit information to the database engine, receive the results back again and display them to the client.
Lyra Belacqua, 11, and her daemon, Pantalaimon, live at Jordan, the largest college at Oxford University.
American humanists must, nevertheless, overcome the paradox of politics by becoming the voice of clarity and reason, the conscience - the daemon - of the nation.
In Daemon Moon Rising, a fiendish sub-cult of Chaos artificers have bound savage daemons into innocuous carnival masks and smuggled them into the Empire.
GHOULISH Debbie Kiernan, Joe Daly as Daemon Crodell and Amy Creighton at preview of Magick Macabre; GORY Joe Daly as Daemon Crodell of Magick Macabre; SAUCY Amy Creighton yesterday
The biometric daemon, about the size of a credit card, would store an individual's data and be carried with the owner at all times.
Encountering various beasts along the way, not only does she enlist the help of a talking armoured bear (voiced by Sir Ian McKellen), but one of the conceits of the story is that in this universe, every person has their own daemon (pronounced demon), which is a physical manifestation of their personality or soul, in animal form.
Pop icon and rising star Daemon Negranni has whetted his taste for the extravagant life, yet a slippery stalker is hounding him by repeatedly invading his hilltop estate and disappearing.
Among the latest picks: Aaron Rosenberg's DAY OF THE DAEMON (1844163660, $7.
Coverage includes manipulating different types of databases; advanced tools for accessing databases; processing XML; using plain sockets and pure HTTP to separate concerns and to distribute business logic across process boundaries; distributed applications with RPC; overcoming internationalization problems; creating sophisticated logging strategies; creating daemon processes; and how to automatically deploy software.