daemon


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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 email 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 ?
The daemons logged the new file signatures, used emergency privileges to access the internal systems of every bandwidth provider in the United States, and added the file signatures to the block list.
The daemon is not simply a static icon, however; it is animated, and thus presents a complex synthesis of form and behavior.
However, the girl and her daemon are soon embroiled in mystery when the enigmatic Mrs Coulter (Kidman) spirits Lyra away from Oxford to become her assistant.
Daemon, the only Scot to survive the blaze, said: "I thought I was going to die.
Daemon, aka Dublin magician Joe Daly, had producers of the show in a panic because of his gory stage act - so much so that he almost had the plug pulled on his appearance.
Lyra Belacqua, 11, and her daemon, Pantalaimon, live at Jordan, the largest college at Oxford University.
Of course, today the daemon is called the con, science and recognized as the ability to know right from wrong or to recognize the confluence of word and deed - the locus of integrity.
In his famous poem " Urworte, Orphisch " ( " Primal Orphic Words, " 1817), Goethe defines the basic elements in human destiny as Daemon, Chance, Love, Necessity, and Hope; Daemon refers to each man's unique, inborn, developmental force, the unalterable law of his own individual growth.
NASDAQ:ERTS) studio, today announced that the critically acclaimed MMORPG, Warhammer[R] Online: Age of Reckoning[R] (WAR), will host a special live event, Daemon Moon Rising, for a limited time during the 2009 Halloween season.
This was the second Kelpies book I have read after loving Roy Gill's Daemon Parallel.
The National Theatre made effective use of puppets but here the young actors mirrored each other, character and daemon.
Daemon has a twin sister, Dee, equally beautiful, and soon the two become best friends.