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 There's no more Bourne shell nowadays. How is being able to break into any linux machine through grub2 secure? Now we already have > /dev/null at the end of the script which means all the standard output (STDOUT) will be written to /dev/null. have a peek at this web-site
Sometimes they’re not named, they’re numbered! How to adjust UI scaling for Chrome? Are the plane and the third dimensional space homeomorphic? Reply Link ma thesh February 2, 2015, 6:16 pm How to get the error help in shell window Reply Link Alex October 19, 2015, 10:02 am Thanks! http://askubuntu.com/questions/350208/what-does-2-dev-null-mean
By default: stdin ==> fd 0 stdout ==> fd 1 stderr ==> fd 2 In script, you use > /dev/null causing: stdin ==> fd 0 stdout ==> /dev/null stderr ==> fd Home Posts About Essential Books Regex Toolkit Staying Secure Online The Ultimate Notebook The Ultimate Pen © 2016 Baron Schwartz. However, this will not work when command will use the standard error (FD # 2).
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| Did you find this question interesting? Reply Link Frank June 30, 2009, 5:15 pm need a command in my bash script to remove some (not all) of the contents of directory2. Please click the link in the confirmation email to activate your subscription. Redirect Stderr To Dev Null And Stdout To File By the way, you need to have a > in front of /dev/null 2>&1.
shell io-redirection openbsd share|improve this question asked Jun 25 '13 at 19:12 Torxed 73031029 add a comment| 1 Answer 1 active oldest votes up vote 37 down vote accepted I believe /dev/null 2 &1 Ambiguous Output Redirect Are there any ways to speed up blender compositor? I'm sure you have something in mind where both good and bad output would normally go to stdout. How to draw and store a Zelda-like map in custom game engine?
Here is a snippet of my code: echo "Enter the number" read $N > text …. more info here How to explain centuries of cultural/intellectual stagnation? & Dev Null If any errors occurs in tar process, i.e: permission denied, no such file or directory ..., the script still be crashed. Redirect Output To Null Windows bash-script null share|improve this question asked Mar 14 '14 at 4:20 JohnMerlino 71341428 1 Redirecting to /dev/null won't prevent crashing, but will clean up the stdout and stderr output streams.
Is the ability to finish a wizard early a good idea? Check This Out I know it's not recommended, but for someone like myself, with scripts they either run daily or don't run for months and then go through a spate of executing them two stdout) and file descriptor '2' is standard error (a.k.a. Is it safe for a CR2032 coin cell to be in an oven? 1 Dev Null
Save a JPG without a background Would it be ok to eat rice using spoon in front of Westerners? Computing only one byte of a cryptographically secure hash function How does the exit command work on a Unix terminal? So you need to modify >/dev/null as follows to redirect both output and errors to /dev/null.Syntax to redirect error and output messages to /dev/null The syntax discussed below works Source share|improve this answer edited Sep 27 '13 at 12:23 answered Sep 26 '13 at 8:31 sivann 28226 2 There is absolutely nothing wrong if you use 2>/dev/null.
Limit Notation. Redirect Stdin To /dev/null He just wanted to know what it means 2>/dev/null –Radu Rădeanu Sep 27 '13 at 15:02 The OP probably changed the question. All about redirection 3.1 Theory and quick reference There are 3 file descriptors, stdin, stdout and stderr (std=standard).
stderr). DDoS: Why not block originating IP addresses? Is the ability to finish a wizard early a good idea? Redirect Stderr And Stdout Well I need to relearn some shell. –Shou Ya Aug 19 '12 at 14:26 In my case, the 2>&1 needed to go at the end, eg: if ping -c
Newer Older Comments UbuntuCommunityAsk!DeveloperDesignDiscourseHardwareInsightsJujuShopMore ›AppsHelpForumLaunchpadMAASCanonical current community chat Ask Ubuntu Ask Ubuntu Meta your communities Sign up or log in to customize your list. 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 This site is not affiliated with Linus Torvalds or The Open Group in any way. have a peek here Browse other questions tagged bash pipe output-redirect dev-null or ask your own question.
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 Bitwise rotate right of 4-bit value Does the Iron Man movie ever establish a convincing motive for the main villain? Does bitcoin have the potential to be subject to a hard fork where miners are forced to choose which fork they will accept, like Etherum? 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
Are the plane and the third dimensional space homeomorphic? Thank you Giuseppe for the tip. To be clear the standard output (stdout) of the command is meant. Also, when I do script > /dev/null why does only STDOUT go to /dev/null and not everything? –sbhatla Mar 26 at 2:26 add a comment| up vote 11 down vote This
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 How to slow down sessions?