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Null device
- A device file that discards all data written to it but reports that the write operation succeeded. This device is called
/dev/null
on Unix and Unix-like systems, NUL:
or NUL
on DOS and CP/M, nul
on newer Windows systems (internally \Device\Null
on Windows NT), NIL:
on Amiga operating systems, and NL:
on OpenVMS. In Windows Powershell, the equivalent is $null
. The null device provides no data to any process that reads from it, yielding EOF immediately. In IBM DOS/360, OS/360 (MFT, MVT), OS/390, and z/OS operating systems, such files would be assigned in JCL to DD DUMMY
. In programmer jargon, the null device may also be called the “bit bucket” or “black hole.” ← Wikipedia
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