Linux black Hole

1 What is a Linux black hole

In the Linux system,/dev/null is a fake device, commonly known as "Linux black Hole".

Any write to/dev/null succeeds, but the data disappears without any feedback, and the read-in data is empty.

2 Linux black Hole What's around

The information that you don't want to display on the screen is often sent to/dev/null, which is used more in shell scripts. This command must be used in conjunction with output redirection.

Such as:

will see the output of all users of the system thrown into the black hole:

<span style= "FONT-SIZE:24PX;" >ls/home >/dev/null</span>

Empty the contents of the file, Without deleting the file:

<span style= "FONT-SIZE:24PX;" >cat/dev/null > Your_file_name</span> 

Note :

<span style= "FONT-SIZE:24PX;"  >cat/dev/null > Your_file_name</span> 

Command and

<span style= "FONT-SIZE:24PX;" >echo > Your_file_name</span> the 

(reference: empast http://www.linuxdiyf.com/viewarticle.php?id=273259)

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Linux black Hole