Where is dev null

In this way, if we put Otherwise, it would give the following:. Another interesting case would be the collection of results in another file as long as an error does not occur, for which we would put:. The content of the article adheres to our principles of editorial ethics. To report an error click here! Your email address will not be published. Add it! It was precisely the explanation he was looking for. Hello, first of all the article is very good!

I apologize. Here's a comment from under that answer: stackoverflow. Those last 2 sentences " In practice it prevents any output from the command both stdout and stderr from being displayed. That's a pretty important piece of information just hanging out there at the end. I'd like it to stick out more.

Show 1 more comment. Sid Sid Nice explanation. The Overflow Blog. Podcast Explaining the semiconductor shortage, and how it might end. Does ES6 make JavaScript frameworks obsolete? Featured on Meta. The second common use is to empty files that you don't want to remove, but you want to lose their content. This can be very important if a running process needs to write to that file and will lose its connection to it if you remove the file and recreate it remember that running processes connect to files using file handles.

If they want to receive email from those scripts, they'll generally code those messages in the scripts themselves and send them using a command like mailx. It has been around since the beginning of the OS and provides some wonderfully handy options for dealing with data that you don't want to see or retain. And, even after so many decades, it still retains a certain mystique.

Sandra Henry-Stocker has been administering Unix systems for more than 30 years. She describes herself as "USL" Unix as a second language but remembers enough English to write books and buy groceries.

She lives in the mountains in Virginia where, when not working with or writing about Unix, she's chasing the bears away from her bird feeders. Here are the latest Insider stories. More Insider Sign Out. Add a comment. Vishrant Vishrant Good example! Nicely explained! It would help me to understand the web attack that I recently came across.

Attacker is injecting some malicious code through POST request which contains above piece of code. First and foremost preventive step is block the IP in firewall as well as pattern of such IPs. Attack was to redirect on 3rd party website on home page loading. Apache server log shown doubtful IP and request. Could someone please clear my doubt? SnehasishKarmakar a legitimate question. I will appreciate if someone can add more details of this comment.

This is the way to execute a program quietly, and hide all its output. Sergey Kalinichenko Sergey Kalinichenko k 71 71 gold badges silver badges bronze badges. The difference between this and what you claimed is best illustrated by swapping the order of the redirects, e. Peter Mortensen 29k 21 21 gold badges 97 97 silver badges bronze badges.

Iurii Vasylenko Iurii Vasylenko 2, 22 22 silver badges 24 24 bronze badges. Let me explain a bit by bit.