Bash Ignore Error Output
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here for a quick overview of the site Help Center Detailed answers to any questions you might have Meta Discuss the workings and policies of this site About Us Learn more about Stack Overflow the company Business Learn more about hiring developers bash ignore error code or posting ads with us Super User Questions Tags Users Badges Unanswered Ask Question _ Super bash script ignore error User is a question and answer site for computer enthusiasts and power users. Join them; it only takes a minute: Sign up Here's how it bash error output to file works: Anybody can ask a question Anybody can answer The best answers are voted up and rise to the top How to ignore error messages in bash on Ubuntu? up vote 7 down vote favorite 1 I'm trying to show bash error output to variable the number of lines, words and characters of all configuration files in /etc/*conf (with command wc). How can I modify the command (or commandline) to not view the error messages? command-line ubuntu-9.10 bash redirection share|improve this question edited Mar 25 '10 at 23:28 quack quixote 31.3k1068114 asked Mar 25 '10 at 22:26 pedro 4814 1 If Roy's answer below doesn't provide what you want, could you provide the command you're trying so we can get an idea of what's not
Bash Error Output To Dev/null
working properly? –Matrix Mole Mar 25 '10 at 22:46 add a comment| 3 Answers 3 active oldest votes up vote 9 down vote accepted wc /etc/*conf 2>/dev/null share|improve this answer answered Mar 25 '10 at 23:33 Dennis Williamson 57.4k10100135 add a comment| up vote 2 down vote i don't have access to a shell right now, but you can try something like cat /etc/*.conf 2> /dev/null | wc -l That should redirect all the errors and leave the output to be passed to wc share|improve this answer answered Mar 25 '10 at 22:39 Roy Rico 2,72733150 this won't allow wc to output word/line/char counts per-file, if that's what the OP wants. it will get the total of all /etc/*conf files. –quack quixote Mar 25 '10 at 23:30 add a comment| up vote 0 down vote Usually just redirect the standard output to /dev/null to ignore the output, but this is not good practice when writing shell scripts Try use -q instead to run the shell in quite mode, which will produce less output. This might not be relevant to the question, but just FYI. share|improve this answer answered May 1 '13 at 7:10 imcoddy 6115 add a comment| You must log in to answer this question. Not the answer you're looking for? Browse other questions tagged command-line ubuntu-9.10 bash redirection . asked 6 years ago viewed 8524 times active 1 year ago Related 4Redirection: How did the extra word get
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Bash Redirect Error Output
Search Forums Show Threads Show Posts Tag Search Advanced Search bash suppress error output Unanswered Threads Find All Thanked Posts Go to Page... unix and linux operating commands How to bash hide error output ignore error in command in bash script? Shell Programming and Scripting Thread Tools Search this Thread Display Modes #1 12-10-2013 http://superuser.com/questions/124215/how-to-ignore-error-messages-in-bash-on-ubuntu postcd Banned Join Date: Oct 2013 Last Activity: 11 August 2016, 12:58 PM EDT Posts: 87 Thanks: 14 Thanked 2 Times in 2 Posts How to ignore error in command in bash script? Hello, i have bash script where im cycling some command for different lines in external file. example: Code: while read domain;do nslookupout=$(nslookup -type=ns $domain) http://www.unix.com/shell-programming-and-scripting/241905-how-ignore-error-command-bash-script.html || true another commands done < filenamewithdomains i added: || true after the command in belief it will just skip failures. But i got: nslookup: '.somedomain.com' is not a legal name (empty label) and it breaken running the script.. please how to achieve so this error is skipped and continuing to the next entry? i know i can fix my domain list so it dont contains inproper values, but i prefer skipping invalid entries. if anyone know how to remove lines in a file containing two dots at one line by sed, please kindly share. Remove advertisements Sponsored Links postcd View Public Profile Visit postcd's homepage! Find all posts by postcd #2 12-10-2013 Akshay Hegde Forum Advisor Join Date: Nov 2012 Last Activity: 28 September 2016, 2:06 AM EDT Posts: 1,783 Thanks: 97 Thanked 620 Times in 553 Posts You can do something like this Code: your command 2>&1 >/dev/null Remove advertisements Sponsored Links Akshay Hegde View Public Profile Find all
discarded by the system. Use /dev/null to send any unwanted output from program/command and syntax is: command >/dev/null This syntax redirects the command standard output messages to https://bash.cyberciti.biz/guide//dev/null_discards_unwanted_output /dev/null where it is ignored by the shell. OR command 2>/dev/null This syntax redirects the command error output messages to /dev/null where it is ignored by the shell. OR command https://ubuntuforums.org/showthread.php?t=1370306 &>/dev/null This syntax redirects both standard output and error output messages to /dev/null where it is ignored by the shell. Example Try searching user vivek in /etc/passwd file: grep vivek error output /etc/passwd && echo "Vivek found" || "Vivek not found" Sample outputs: vivek:x:1000:1000:Vivek Gite,,,,:/home/vivek:/bin/bash Vivek found To ignore actual output and just display the message, modify your command as follows: grep vivek /etc/passwd >/dev/null && echo "Vivek found" || "Vivek not found" Sample outputs: Vivek found Consider the following example from the exit status chapter. The output of grep "^$username" $PASSWD_FILE bash error output > /dev/null is send to /dev/null where it is ignored by the shell. #!/bin/bash # set var PASSWD_FILE=/etc/passwd # get user name read -p "Enter a user name : " username # try to locate username in in /etc/passwd # grep "^$username" $PASSWD_FILE > /dev/null # store exit status of grep # if found grep will return 0 exit stauts # if not found, grep will return a nonzero exit stauts status=$? if test $status -eq 0 then echo "User '$username' found in $PASSWD_FILE file." else echo "User '$username' not found in $PASSWD_FILE file." fi ← Empty file creationHomehere documents → Retrieved from "https://bash.cyberciti.biz/wiki/index.php?title=/dev/null_discards_unwanted_output&oldid=3325" Category: Redirection Navigation menu Personal tools Log in Namespaces Page Discussion Variants Views Read View source View history More Search Navigation Main pageRecent changesRandom pageHelp Tools What links hereRelated changesSpecial pagesPermanent linkPage information Print/export Create a bookDownload as PDFPrintable version This page was last modified on 29 March 2016, at 17:50. Content is available under Attribution-Noncommercial-Share Alike 3.0 Unported unless otherwise noted. Privacy policy About Linux Shell Scripting Tutorial - A Beginner's handbook Disclaimers Mob
Get Kubuntu Get Xubuntu Get Lubuntu Get UbuntuStudio Get Mythbuntu Get Edubuntu Get Ubuntu-GNOME Get UbuntuKylin Ubuntu Code of Conduct Ubuntu Wiki Community Wiki Other Support Launchpad Answers Ubuntu IRC Support AskUbuntu Official Documentation User Documentation Social Media Facebook Twitter Useful Links Distrowatch Bugs: Ubuntu PPAs: Ubuntu Web Upd8: Ubuntu OMG! Ubuntu Ubuntu Insights Planet Ubuntu Activity Page Please read before SSO login Advanced Search Forum The Ubuntu Forum Community Ubuntu Official Flavours Support General Help [all variants] suppress stderr in a bash script Having an Issue With Posting ? Do you want to help us debug the posting issues ? < is the place to report it, thanks ! Results 1 to 7 of 7 Thread: suppress stderr in a bash script Thread Tools Show Printable Version Subscribe to this Thread… Display Linear Mode Switch to Hybrid Mode Switch to Threaded Mode January 2nd, 2010 #1 Andreas1 View Profile View Forum Posts Private Message Frothy Coffee! Join Date Sep 2007 Location Vienna Beans 234 suppress stderr in a bash script hi, i have a bash script that in some cases will print out error messages from various commands like ls, grep, head, tail. currently i see the following options: -supplement each single one of those commands with "2>/dev/null" <--doing that currently -tell the people who use the script to invoke it with "2>/dev/null" -build (otherwise unnecessary) tests for files and directories to prevent errors -have confusing error messages printed to the user but i was wondering if there was some kind of global setting for that, to the same effect as invoking the script itself with "2>/dev/null", maybe like a silent argument in the "#!/bin/bash" line or something? hope i am making sense... As you can see from my history, i was once an enthusiastic ubuntu user. I would hereby like to assert that i no longer recommend using ubuntu to anyone. I recommend using one of the many distributions that do not include ad-/spyware by