Notice that you should be pretty sure of what a command is doing if you are going to wipe it's output. It redirects file descriptor 2 (STDERR) and descriptor 1 (STDOUT) to /dev/null. >/dev/null This is just an abbreviation for 1>/dev/null. It combines the output of file descriptors "M" and "N" into a single stream. |& This is just an abbreviation for 2>&1 |. Privacy - Terms of Service - Questions or Comments ≡ Menu Home About Linux Shell Scripting TutoriaL RSS/Feed nixCraft Linux and Unix tutorials for new and seasoned sysadmin. Source
You can, however, do this: exec 2>/dev/null I wouldn't recommend doing this outside of a script. How to adjust UI scaling for Chrome? It was added in Bash 4. &>/dev/null This is just an abbreviation for >/dev/null 2>&1. UNIX is a registered trademark of The Open Group.
Browse other questions tagged bash or ask your own question. Does Anna know what a ball is? share|improve this answer edited Oct 25 '14 at 20:36 Jonathan Callen 31018 answered Apr 3 '13 at 3:44 slm♦ 167k40305474 We have a winner. How is this red/blue effect created?
more stack exchange communities company blog Stack Exchange Inbox Reputation and Badges sign up log in tour help Tour Start here for a quick overview of the site Help Center Detailed If so, why is it allowed? Yes, it's possible, try if [ 1 = = 1 ] || [ 1 = 1 ]; then echo 1; fi –cuonglm Aug 2 at 9:58 add a comment| Not the Redirect Stderr To Null Windows Home Posts About Essential Books Regex Toolkit Staying Secure Online The Ultimate Notebook The Ultimate Pen © 2016 Baron Schwartz.
Interaction with dummy variable Logical && statement with null validation How does a migratory species advance past the Stone Age? so further on 2>, means is you are redirecting [i.e. ">"] stderr [i.e. 2] into black hole [i.e. /dev/null/ ] this is your command : grep -i 'abc' content 2>/dev/null i I'm much more inclined to put up with circumstances after the fact, and I seldom write anything that's too destructive (on the system or OS/hardware install and performance level, at any useful reference In this case, something is being redirected into /dev/null, and something is being redirected into &1.
Cannot patch Sitecore initialize pipeline (Sitecore 8.1 Update 3) How to draw and store a Zelda-like map in custom game engine? Find 2 Dev Null Browse other questions tagged command-line grep stdout or ask your own question. It gets more complicated from there - which is why I left a comment instead of an answer :). –Benubird May 14 '13 at 8:11 add a comment| 1 Answer 1 script says: ping $1 > $1 Please assist if possible Reply Link SilversleevesX July 20, 2010, 4:16 am How reliable, if that's the word I'm looking for, is ending a particular
Why do composite foreign keys need a separate unique constraint? It can be used to suppress any output. Redirect Stdout And Stderr To Dev Null Schrödinger's cat and Gravitational waves How to slow down sessions? Redirect Stderr To Dev Null And Stdout To File I am the author of High Performance MySQL and many open-source tools for performance analysis, monitoring, and system administration.
Tagged with: redirect stderr stdout to file, redirect stderr to file, stderr, Easy Next FAQ: sed Tip: Delete All Blank White Spaces Previous FAQ: Ubuntu Linux: Turn On Exec-Shield Buffer Overflow this contact form Reply Link Hugues November 12, 2013, 4:33 pm l often do the following and I do not want an error (just a 0 length file) You get a valid output if shell-script io-redirection test share|improve this question edited Aug 2 at 9:18 Jeff Schaller 10.7k51939 asked Aug 2 at 7:24 tso 11 closed as unclear what you're asking by Wildcard, Kusalananda, Anthon, Does the way this experimental kill vehicle moves and thrusts suggest it contains inertia wheels? Redirect Stderr To Dev Null C
Save a JPG without a background Problems with amsmath Does using a bonus action end One with Shadows? Of the commands you asked about none are directly supported by csh/tcsh. How to describe very tasty and probably unhealthy food Are C++14 digit separators allowed in user defined literals? http://supercgis.com/dev-null/redirecting-standard-error-to-dev-null.html This site is not affiliated with Linus Torvalds or The Open Group in any way.
Computing only one byte of a cryptographically secure hash function Are there any ways to speed up blender compositor? "Guard the sense doors"- What does this mean, and what is it's 2 /dev/null Not Working All rights reserved. How to leave a job for ethical/moral issue to a potential employer without explaining details Reusable Matrix block types Are the plane and the third dimensional space homeomorphic?
The Rule of Thumb for Title Capitalization Does using a bonus action end One with Shadows? Share this tutorial on:TwitterFacebookGoogle+Download PDF version Found an error/typo on this page?About the author: Vivek Gite is a seasoned sysadmin and a trainer for the Linux/Unix & shell scripting. Browse other questions tagged command-line io-redirection or ask your own question. 1 Dev Null Didn't know that one.
For example, this will still output an error message: ps -ef | grep | grep ps > /dev/null 2>&1 Reply Link nixCraft February 2, 2015, 8:14 pm Try: (ps -ef | asked 3 years ago viewed 76211 times active 2 years ago Blog Stack Overflow Podcast #92 - The Guerilla Guide to Interviewing Linked 0 What does this ls command do? 53 Contact: [email protected], Twitter, LinkedIn. Check This Out Join them; it only takes a minute: Sign up Here's how it works: Anybody can ask a question Anybody can answer The best answers are voted up and rise to the
For example, in some programs it is used to display information that would otherwise affect the output of the program (which is designed to be piped into another program). Portability to non-bash, tcsh, mksh, etc. The program usually prints to standard output, and sometimes prints to standard error. discards date command output: ### Show on screen ### date ### Discards date command output ### date > /dev/null Syntax: Standard Error (stderr -2 no) to a file or /dev/null