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Bash Script Exit On Command Error


The return status of AND and OR lists is the exit status of the last command executed in the list." Again, we can use the true and false commands to see Will output 1 (or instead exit if set -e is present), however: echo `exit 1` echo $? So -e is about the exit status of commands being non-zero, not about syntax errors in your script. How's the CMD trip bonuses from extra legs work? this contact form

Adopt A Jet/Book Is the following extension of finite state automata studied? It would be nice if you could fix these problems, either by deleting the lock files or by rolling back to a known good state when your script suffers a problem. COMMAND_LAST # Will exit with status of last command. Not the intended behavior!

Bash Script Exit If Command Fails

Thanks for the help. In practice, all shells ignore failures of the elements of the pipeline other than the last one, and exhibit one of two behaviors regarding the last pipeline element: ATT ksh and I have to say this doesn't feel very robust, but if it works for you, perhaps it is acceptable. To my surprise, I can't achieve this. (set -e is not enough.) Example: #!/bin/bash # Do exit on any error: set -e readonly a=(1 2) # A syntax error is here:

  • Originally Posted by mssever The easiest way to ignore errors from one single command is to do Code: somecommand || true Why didn't I think of that??!
  • Will output 0 after a blank line.
  • echo 'Bad: has not aborted execution on syntax error!' Result (bash-3.2.39 or bash-3.2.51): $ ./sh-on-syntax-err ./sh-on-syntax-err: line 10: #: syntax error: operand expected (error token is "#") status 1 Bad: has
  • share|improve this answer edited Jan 11 at 17:11 answered Oct 23 '13 at 16:19 Gilles 369k666681119 Recently I experimented a little and discovered a convenient way of fixing ||
  • For example, all of ash, bash, pdksh, ksh93 and zsh exit without displaying foo on the following examples: set -e; (set +e; false); echo "This should be displayed" set -e; (!
  • on a true command.
  • This can be fixed by using: if [ "$filename" = "foo" ]; When using $@ variable, you should always quote it or any arguments containing a space will be expanded in
  • lskdf # Unrecognized command.
  • perhaps this must be reported as a bug/wish to bash developers The answer is definitely no!

Notice that we explicitly exit from the script at the end of trap command, otherwise the script will resume from the point that the signal was received. UNIX is a registered trademark of The Open Group. I've appended echo 'Bad2: has not aborted the execution after bad main!' as the last to your example, and the output is: $ LC_ALL=C ./sh-on-syntax-err ./sh-on-syntax-err: line 6: #: syntax error: Bash Shell Script Exit function directoryExists { cd $1 if [ $? = 0 ] then echo -e "${green}$1${NC}" else echo -e "${red}$1${NC}" fi } # EXE directoryExists "~/foobar" directoryExists "/www/html/drupal" The script works, but

Using -e gives you error checking for free. Bash Script Command Exit Code There is a little trick that can be used to fix this: run the inner command in background, and then immediately wait for it. ERR) but already tested that: trap ... The list constructs use exit codes to understand whether a command has successfully executed or not.

if [ $filename = "foo" ]; will fail if $filename contains a space. Bash Script Exit While Loop Again, for readability you may want to use┬áset -o errexit. Toggle navigation Benjamin Cane Home Archive RSS Twitter Mail Feed Understanding Exit Codes and how to use them in bash scripts When writing a script that calls other commands, how do I'm looking for a way to make it always abort on syntax errors. –imz -- Ivan Zakharyaschev Jul 8 '13 at 20:30 add a comment| up vote 0 down vote First,

Bash Script Command Exit Code

Be prepared for spaces in filenames Someone will always use spaces in filenames or command line arguments and you should keep this in mind when writing shell scripts. There are other constructs you could use: command if [ "$?"-ne 0]; then echo "command failed"; exit 1; fi could be replaced with command || { echo "command failed"; exit 1; Bash Script Exit If Command Fails Modern soldiers carry axes instead of combat knives. Bash Script Exit With Error Message Adopt A Jet/Book How rich can one single time travelling person actually become?

Is there possibly some way around that? http://waspsoft.com/bash-script/bash-script-command-not-found-error.html TERM Terminate - this signal is sent when someone sends the TERM signal using the kill command. I only hope I clarified the set -e statement! Other shells approximate the behavior by exiting if the last element of the pipeline returns a nonzero status. Bash Script Exit On Failure

up vote 5 down vote favorite 1 I made the following script: # !/bin/bash # OUTPUT-COLORING red='\e[0;31m' green='\e[0;32m' NC='\e[0m' # No Color # FUNCTIONS # directoryExists - Does the directory exist? Also, note the inclusion of the LINENO environment variable which will help you identify the exact line within your script where the error occurred. #!/bin/bash # A slicker error handling routine In a GNU C macro envSet(name), what does (void) "" name mean? navigate here Buy on Amazon Sponsored by Become a Sponsor Copyright © Benjamin Cane 2014 - Contact the Author David Pashley.com Home Articles Dial On Demand with WVDial Writing Robust Bash Shell Scripts

Is the standard Canon 18-55 lens the same as 5 years ago? Bash Script Exit Function Adv Reply December 11th, 2008 #8 jasper.davidson View Profile View Forum Posts Private Message 5 Cups of Ubuntu Join Date Jul 2008 Beans 26 Re: Make shell script exit as Didn't know about Code Review. –skozin Jan 11 at 17:27 add a comment| up vote 2 down vote To expand on the @Gilles' answer: Indeed, set -e doesn't work inside commands

The answer is exit codes, exit codes are important and this article describes how to use them in your scripts and understand them in general.

User contributions on this site are licensed under the Creative Commons Attribution Share Alike 4.0 International License. How to book a flight if my passport doesn't state my gender? Do something like this: Code: #!/bin/sh set -e ... Bash Script Exit If No Arguments Depending on the type of syntax error, the script might not even be executed at all.

trap : 0 echo >&2 ' ************ *** DONE *** ************ ' share|improve this answer answered Mar 6 '14 at 12:19 supercobra 2,90242737 1 trap 'abort' 0 <- why you You can check for files with files open by using lsof. To check the exit code we can simply print the $? his comment is here The fix is to use: if [ ! -e $lockfile ]; then trap "rm -f $lockfile; exit" INT TERM EXIT touch $lockfile critical-section rm $lockfile trap - INT TERM EXIT else

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