NUL:

NUL:

In the CP/M, DOS, and Microsoft Windows operating systems, the name NUL: or simply NUL designates a special file that discards all data written to it (but reports that the write operation succeeded), and provides no data to any process that reads from it (yielding EOF immediately).

In the Windows NT system and its successors, it is named \Device\Null internally, and the DOS NUL is an alias for it. However, at the command prompt, \\.\Null is not a valid destination, since the command prompt can only access a device through an alias.


Usage

The NUL: file is typically used for disposing of unwanted output streams of a process, or as a convenient empty file for input streams. This is usually done by redirection. For example, PAUSE > NUL waits for the user to press any key without printing anything to the screen.

This concept is roughly equivalent to the /dev/null of Unix-like systems, the NIL: of Amiga operating systems, and the NL: of OpenVMS.

Note that on DOS, NUL is a very slow destination, slower than buffered file access. On modern machines this is not significant.


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  • nul — nul …   Dictionnaire des rimes

  • nul — nul, nulle [ nyl ] adj. et pron. • 842; lat. nullus I ♦ A ♦ Adj. indéf. Littér. (accompagné d une négation, et placé devant le nom) Pas un. ⇒ aucun. Littér. (au plur.) « Nulles paroles n égaleront jamais la tendresse d un tel langage » (Musset).… …   Encyclopédie Universelle

  • nul — nul, nulle (nul, nu l ) adj. 1°   Aucun avec négation. •   Nulle autre religion que la chrétienne n a connu que l homme est la plus excellente créature, et en même temps la plus misérable, PASC. Pens. part. II, art. 4. •   Nul mortel en ces lieux …   Dictionnaire de la Langue Française d'Émile Littré

  • nul — NUL, Ă, nuli, e, adj. 1. Care se reduce la nimic, care nu valorează nimic sau nu se manifestă in nici un fel; inexistent. ♦ (mat.) Care reprezintă valoarea zero. ♦ (Despre meciuri) Care se termină la egalitate. 2. (Despre acte juridice) Fără… …   Dicționar Român

  • nul — NUL, nulle. adj. Aucun, pas un. Nul homme, nul homme vivant. nulle ordonnance. je n en connois nul. nul de tous ceux qui y ont esté n en est revenu. nul n en sera excepté. il n a nulle raison. je n en ay nulle connoissance. celà est de nul usage …   Dictionnaire de l'Académie française

  • nul — Nul, m. Nemo, et Nullus, duquel mot il vient par apocope de la syllabe Lus, combien que l on die aussi Nully, et en aucuns lieux Nulluy, sans ce retranchement de la derniere syllabe. Mais le François, comme font l Italien et l Espagnol aussi, en… …   Thresor de la langue françoyse

  • NUL — may refer to: National University of Lesotho National Urban League, an American civil rights organization Nul (band), also spelled NuL, a South African band who base the distribution of their music on Open Source principles Nul, rulers of a… …   Wikipedia

  • Nul — Nul, a. [F. See {Null}, a.] (Law) No; not any; as, nul disseizin; nul tort. [1913 Webster] …   The Collaborative International Dictionary of English

  • nul- — DEFINICIJA kao prvi dio riječi upućuje da drugi dio stoji u vezi s nulom [nul forma matematička forma kojoj su koeficijenti jednaki nuli; nul matrica matrica kojoj su svi elementi nula] ETIMOLOGIJA lat. nullus, njem. Null …   Hrvatski jezični portal

  • NUL — steht für: National University of Lesotho, die Universität Lesothos National Urban League, US amerikanische Bürgerrechtsbewegung Nullzeichen, dem Steuerzeichen in Zeichencodierungen an der Position 0 virtuelle Gerätedatei unter DOS und… …   Deutsch Wikipedia

  • nul — Mot Monosíl·lab Adjectiu variable …   Diccionari Català-Català

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