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Linux Error Redirect /dev/null

Follow him on Twitter. This site is not affiliated with Linus Torvalds or The Open Group in any way. It's free: ©2000-2016 nixCraft. Some more common use case command > /dev/null 2>&1 & run command in background, discard stdout and stderr command >> /path/to/log 2>&1 & run command and redirect stdout and stderr to weblink

The file in /dev/ is just for convenience. –Chris Down May 14 '13 at 3:51 @ChrisDown you're right, /dev/stderr is just a link. In this case, something is being redirected into /dev/null, and something is being redirected into &1. Reply Link John June 4, 2014, 1:33 pmTypo: command 2>&1 > log.txt Should be: command > log.txt 2>&1 Reply Link Nix Craft June 5, 2014, 10:36 amThanks for the heads up! N(e(s(t))) a string Find first non-repetitive char in a string Soft question: What exactly is a solver in optimization? http://askubuntu.com/questions/350208/what-does-2-dev-null-mean

The program usually prints to standard output, and sometimes prints to standard error. How to deal with a coworker who is making fun of my work? 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 It can be used to suppress any output.

use: command 2>&1 1>/dev/null Reply Link nixCraft October 6, 2011, 12:54 amNo, it does not matters. For reference see the Advanced Bash-Scripting Guide. I am the author of High Performance MySQL and many open-source tools for performance analysis, monitoring, and system administration. What does Differential Geometry lack in order to "become Relativity" - References Why do people move their cameras in a square motion?

I've not dealt much with other shells outside of csh and tcsh. I mean: I want to launch a command: - if all goes good --> no output - if something goes wrong --> output of errorsThanks, Ciccio Reply Link SilversleevesX October 2, USB in computer screen not working more hot questions question feed default about us tour help blog chat data legal privacy policy work here advertising info mobile contact us feedback Technology http://unix.stackexchange.com/questions/70963/difference-between-2-2-dev-null-dev-null-and-dev-null-21 But, if you can't figure it out on your own, you shouldn't try, as you are more likely to break something fatally than succeed. –Benubird May 13 '13 at 8:11

Privacy - Terms of Service - Questions or Comments Next Previous Contents 3. Tagged with: EasyNext FAQ: FreeBSD: (EE) Failed to load module "fbdev" (module does not exist, 0) Error and SolutionPrevious FAQ: FreeBSD 10: Apply Binary Updates To Keep Base System Up To If you don't specify a number then the standard output stream is assumed but you can also redirect errors > file redirects stdout to file 1> file redirects stdout to file Reply Link ma thesh February 2, 2015, 6:16 pmHow to get the error help in shell window Reply Link Alex October 19, 2015, 10:02 amThanks!

By default, if you don’t name or number one explicitly, you’re talking about STDOUT. How can I redirect command error output /dev/null on a Linux or Unix-like system using Bash shell? Contact: [email protected], Twitter, LinkedIn. Public huts to stay overnight around UK UV lamp to disinfect raw sushi fish slices What to do with my out of control pre teen daughter Uncertainty principle Difficult limit problem

The built-in numberings for them are 0, 1, and 2, in that order. have a peek at these guys Converting Game of Life images to lists What does a profile's Decay Rate actually do? 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. I'm Baron Schwartz, the founder and CEO of VividCortex.

Public huts to stay overnight around UK How to concatenate three files (and skip the first line of one file) an send it as inputs to my program? These three file descriptors (you can think of them as “data pipes”) are often called STDIN, STDOUT, and STDERR. It was added in Bash 4. &>/dev/null This is just an abbreviation for >/dev/null 2>&1. http://cygnussoft.com/linux-error/linux-error-correction.html They were in zsh from the start and have only been added recently to bash.

Didn't know that one. OR read more like this:Linux Redirect Error Output To FileUnix and Linux: Redirect Error Output To null CommandLinux / Unix Find Command: Avoid Permission Denied MessagesBASH Shell: How To Redirect stderr xaprb.com/blog/2006/06/06/what-does-devnull-21-mean –richard.g Dec 15 '13 at 9:08 add a comment| 1 Answer 1 active oldest votes up vote 138 down vote accepted You use: yourcommand > /dev/null 2>&1 If it should

Reply Link Hugues November 12, 2013, 4:33 pml often do the following and I do not want an error (just a 0 length file) You get a valid output if the

You can also use >> to append. How to create a company culture that cares about information security? share|improve this answer edited Sep 26 '13 at 13:55 answered Sep 26 '13 at 8:38 Warren Hill 10.4k104463 add a comment| up vote 10 down vote In short, it redirects stderr I contribute to various database communities such as Oracle, PostgreSQL, Redis and MongoDB.

Browse other questions tagged command-line grep stdout or ask your own question. 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 asked 3 years ago viewed 125512 times active 1 year ago Linked 3 Get current ssh session's originating IP without being superuser Related 29What does outputting to /dev/null accomplish in bash http://cygnussoft.com/linux-error/linux-error-25-on-boot-up.html Specific word to describe someone who is so good that isn't even considered in say a classification Why do people move their cameras in a square motion?

And why grep -ri? –Radu Rădeanu Sep 26 '13 at 9:02 By the way, he could also be looking for the string /support/security/bulletins/ in the file called content =). Thank you sir. –yegeniy Feb 28 '14 at 2:47 add a comment| Your Answer draft saved draft discarded Sign up or log in Sign up using Google Sign up using Here’s an example command: wibble > /dev/null 2>&1 Output redirection The greater-thans (>) in commands like these redirect the program’s output somewhere. So following two are the same command:command 2>&1 1>/dev/nullANDcommand 1>/dev/null 2>&1 Reply Link Anonymous August 25, 2012, 7:33 pmHello,The order is important :$ ls non_existing_folder 1>/dev/null 2>&1(no output)$ ls non_existing_folder 2>&1

share|improve this answer edited Oct 25 '14 at 20:36 Jonathan Callen 31018 answered Apr 3 '13 at 3:44 slm♦ 166k40305474 We have a winner. However, this will not work when command will use the standard error (FD # 2). These 2 are equivalents: > file and >file. asked 3 years ago viewed 125512 times active 1 year ago Linked 3 Get current ssh session's originating IP without being superuser Related 29What does outputting to /dev/null accomplish in bash

foo(){ : } 2>&1 | tee foo.logOR#!/bin/bash # My script to do blah ... { command1 command2 } 2>&1 | tee script.log Share this tutorial on:TwitterFacebookGoogle+Download PDF version Found an error/typo Equation which has to be solved with logarithms How exactly std::string_view is faster than const std::string&?