Bash On Error Resume Next
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On Error Resume Next Vbscript
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On Error Resume Next Vbscript Example
up Ignoring specific errors on Shell Script up vote 11 down vote favorite 6 I have a small snippet of a shell script which has the potential to throw many errors. I have the script currently set to globally stop on all errors. However i would like for this small sub-section is slightly different. Here is the snippet: recover database using backup on error resume next excel vba controlfile until cancel || true; auto I'm expecting this to eventually throw a "file not found" error. However i would like to continue executing on this error. For any other error i would like the script to stop. What would be the best method of achieving this? Bash Version 3.00.16 bash shell unix share|improve this question edited Jul 24 '13 at 13:35 asked Jul 24 '13 at 9:38 Stunt 1471212 2 Does this help? And, Welcome to SO! :) –S.R.I Jul 24 '13 at 9:42 That does help to improve my error reporting however it does not include anything for handling different errors in a different manor. I'm essentially trying to mimic the try{}catch{} from c# –Stunt Jul 24 '13 at 10:00 add a comment| 2 Answers 2 active oldest votes up vote 29 down vote accepted In order to prevent bash to ignore error for specific commands you can say: some-arbitrary-command || true This would make the script continue. For example, if you have the following script: $ cat foo set -e echo 1 some-arbitrary-command || true echo 2 Executing it wou
ensuring they always perform necessary cleanup operations, even when something unexpected goes wrong. The secret sauce is a pseudo-signal provided by bash, called EXIT, that you can trap; commands or functions trapped on it will execute when the script
On Error Resume Next Asp
exits for any reason. Let's see how this works. The basic code structure is like this:
On Error Resume Next Powershell
#!/bin/bash function finish { # Your cleanup code here } trap finish EXIT You place any code that you want to be certain on error resume next uft to run in this "finish" function. A good common example: creating a temporary scratch directory, then deleting it after. #!/bin/bash scratch=$(mktemp -d -t tmp.XXXXXXXXXX) function finish { rm -rf "$scratch" } trap finish EXIT You can then download, generate, http://stackoverflow.com/questions/17830326/ignoring-specific-errors-on-shell-script slice and dice intermediate or temporary files to the $scratch directory to your heart's content. [1] # Download every linux kernel ever.... FOR SCIENCE! for major in {1..4}; do for minor in {0..99}; do for patchlevel in {0..99}; do tarball="linux-${major}-${minor}-${patchlevel}.tar.bz2" curl -q "http://kernel.org/path/to/$tarball" -o "$scratch/$tarball" || true if [ -f "$scratch/$tarball" ]; then tar jxf "$scratch/$tarball" fi done done done # magically merge them into some frankenstein kernel ... # That done, copy it to a destination http://redsymbol.net/articles/bash-exit-traps/ cp "$scratch/frankenstein-linux.tar.bz2" "$1" # Here at script end, the scratch directory is erased automatically Compare this to how you'd remove the scratch directory without the trap: #!/bin/bash # DON'T DO THIS! scratch=$(mktemp -d -t tmp.XXXXXXXXXX) # Insert dozens or hundreds of lines of code here... # All done, now remove the directory before we exit rm -rf "$scratch" What's wrong with this? Plenty: If some error causes the script to exit prematurely, the scratch directory and its contents don't get deleted. This is a resource leak, and may have security implications too. If the script is designed to exit before the end, you must manually copy 'n paste the rm command at each exit point. There are maintainability problems as well. If you later add a new in-script exit, it's easy to forget to include the removal - potentially creating mysterious heisenleaks. Keeping Services Up, No Matter What Another scenario: Imagine you are automating some system administration task, requiring you to temporarily stop a server... and you want to be dead certain it starts again at the end, even if there is some runtime error. Then the pattern is: function finish { # re-start service sudo /etc/init.d/something start } trap finish EXIT sudo /etc/init.d/something stop # Do the work... # Allow the script to end and the trapped finish function to start the # daemon back up. A concrete example: s
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 https://ubuntuforums.org/showthread.php?t=86619 IRC Support AskUbuntu Official Documentation User Documentation Social Media Facebook Twitter Useful Links http://superuser.com/questions/457571/how-can-i-continue-a-loop-in-bash-after-an-application-returned-an-error 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 Specialised Support Development & Programming Programming Talk BASH scripting question Having an Issue With Posting ? Do you want to help us debug the on error posting issues ? < is the place to report it, thanks ! Results 1 to 5 of 5 Thread: BASH scripting question Thread Tools Show Printable Version Subscribe to this Thread… Display Linear Mode Switch to Hybrid Mode Switch to Threaded Mode November 6th, 2005 #1 NewWithoutClue View Profile View Forum Posts Private Message Gee! These Aren't Roasted! Join Date Oct 2005 Location Lethbridge,Alberta Beans 137 on error resume DistroUbuntu 7.04 Feisty Fawn BASH scripting question Hey, sup? Question, if i may: In Visual Basic there is a statement "ON ERROR RESUME NEXT", this statement basically does what it says it does: skips an error causing line of code and continues with the current flow of logic ( for the current sub or function ). Now, i want to know of a equivlent for BASH. Does one exist? if not, know any tricks? Thanks, Paul. s/Windows/Linux/ Adv Reply November 6th, 2005 #2 23meg View Profile View Forum Posts Private Message Ubuntu QA Team Join Date Mar 2005 Beans 6,040 Re: BASH scripting question AFAIK in bash error causing lines will be skipped by default. Errors will only be handled if you write error handlers that instruct bash to terminate the script (error_exit) or do something else. Previously known as 23meg Adv Reply November 6th, 2005 #3 NewWithoutClue View Profile View Forum Posts Private Message Gee! These Aren't Roasted! Join Date Oct 2005 Location Lethbridge,Alberta Beans 137 DistroUbuntu 7.04 Feisty Fawn Re: BASH scripting question Originally Posted by 23meg AFAIK in bash error causing lines will be skipped by default. Errors will only be ha
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 or posting ads with us Super User Questions Tags Users Badges Unanswered Ask Question _ Super 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 works: Anybody can ask a question Anybody can answer The best answers are voted up and rise to the top How can I continue a loop in bash after an application returned an error? up vote 1 down vote favorite I save images with: #!/bin/bash for i in {1..30000} do wget "http://services.runescape.com/m=itemdb_rs/3809_obj_sprite.gif?id="$i done Is there a way to speed up the process? Sometimes a URL does not exist and I get: connected. HTTP request sent, awaiting response... 404 Not found 2012-08-04 18:09:36 ERROR 404: Not found. How can I continue after this error? bash wget share|improve this question edited Aug 4 '12 at 16:25 Oliver Salzburg♦ 56k35185245 asked Aug 4 '12 at 16:17 Szymon Toda 4291922 If you have an additional question about how to download out only certain object, please ask an additional question. Mixing two subjects in one question just over-complicates the matter :) –Oliver Salzburg♦ Aug 4 '12 at 16:26 @OliverSalzburg - Your comment is spot on. But you chose to edit the title to reflect the question you answered. Neglecting to notice that there where two answers answering his other question. –Nifle Aug 4 '12 at 16:37 @Nifle: Feel free to read the history of the question and change it if you feel that I've missed the point with my edit. Also, please note that I edited and commented on the question before I wrote my answer. –Oliver Salzburg♦ Aug 4 '12 at 16:39 add a comment| 2 Answers 2 active oldest votes up vote 7 down vote accepted Try wget "http://s.../m=itemdb_rs/3809_obj_sprite.gif?id="$i || true This way, if wget fails, the result of that line is still zero and your script continues. To learn how to properly handle errors in a bash script, check out the following resources: Error handling in BASH Bash: Error handling share|improve this answer answered Aug 4 '12 at 16:30 Oliver Salzburg♦ 56k35185245 +1 This is a good suggestion! –Canha Aug 4 '12 at 17:07 add a comment| up vote 0 down vote You could try something like this. #!/bin/bash for i in {1..3000