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Bash Quit Script On Error


You want [[ $(id -u) != 0 ]]; then. –Tim Kennedy Nov 4 '11 at 17:32 4 If you /must/ have a one-liner, try this on for size: [ "$UID" Exit and Exit Status... 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. Unix & Linux Stack Exchange works best with JavaScript enabled current community chat Unix & Linux Unix & Linux Meta your communities Sign up or log in to customize your list. http://waspsoft.com/bash-exit/bash-script-quit-on-error.html

iteration done"; done ; echo "loop done" ) share|improve this answer edited Nov 7 '15 at 15:07 don_crissti 28.2k56595 answered Nov 7 '15 at 13:24 Achim 12 add a comment| Your asked 7 years ago viewed 190922 times active 1 month ago Visit Chat Linked 162 Checking Bash exit status of several commands efficiently 14 The difference between $* and $@ 5 share|improve this answer edited Sep 12 '14 at 15:22 answered Sep 12 '14 at 14:56 kavadias 30148 add a comment| up vote 3 down vote Instead of if construct, you can The problem is when the curl command fails, the loop retries the command five times - if all attempts are unsuccessful the for loop finishes and the main script resumes -

Bash Exit Script With Error Code

How to pluralize "State of the Union" without an additional noun? You're example script, as written, should exit after the first curl command failure the first time it calls false if errexit is set. Script: #!/bin/bash touch /root/test 2> /dev/null if [ $? -eq 0 ] then echo "Successfully created file" exit 0 else echo "Could not create file" >&2 exit 1 fi With the You could fix this using a backup and a trap, but you also have the problem that the site will be inconsistent during the upgrade too.

  • bash scripting share|improve this question asked Sep 4 '09 at 9:51 samoz 20.7k39108167 add a comment| 6 Answers 6 active oldest votes up vote 221 down vote accepted Try this statement:
  • echo 'Bad: has not aborted execution on syntax error!' Result: $ ./sh-on-syntax-err ./sh-on-syntax-err: line 6: #: syntax error: operand expected (error token is "#") status 1 Bad: has not aborted execution
  • Fortunately bash provides a way to run a command or function when it receives a unix signal using the trap command.
  • The list constructs use exit codes to understand whether a command has successfully executed or not.
  • Removing if: #!/bin/bash set -e # exit on any error readonly a=(1 2) # A syntax error is here: (( "${a[#]}" == 2 )) echo status $?
  • But I find it still unreasonable to continue executing afte a syntax error.
  • In that case, the || does not trigger and the exit command is not executed.
  • For more on set -e, see Greg's FAQ #105. –John1024 Nov 6 '15 at 7:55 @John1024 Thanks.
  • https://www.gnu.org/software/bash/manual/bash.html#The-Set-Builtin Try a slightly adapted example posted by RobertL.

Not the intended behavior! trap command signal [signal ...] There are many signals you can trap (you can get a list of them by running kill -l), but for cleaning up after problems there are only So, what's the problem with this function? Exit Bash Shell And given that I'm no bash expert, it leads me to believe that my logic is faulty, and there's something wrong with this methodology, otherwise, I feel others would have given

It is also important that your scripts return a meaningful exit status when they finish. GTIN validation How could banks with multiple branches work in a world without quick communication? The Linux Documentation Project has a pretty good table of reserved exit codes and what they are used for. Force Microsoft Word to NEVER auto-capitalize the name of my company How to extrude a face parallel to another?

Limit involving exponentials and arctangent without L'Hôpital A simple visual puzzle to die for no outgoing connection via ipv4 Dennis numbers 2.0 Meaning of "soul-sapping" Were slings used for throwing hand Bash Exit Function An OR list has the form command1 || command2 command2 is executed if, and only if, command1 returns a non-zero exit status. Checking the exit status There are several ways you can get and respond to the exit status of a program. Unfortunately it means you can't check $?

Bash Script Exit With Error Message

Sample Script: #!/bin/bash touch /root/test echo created file The above sample script will execute both the touch command and the echo command. In the bash manual there is no hint that set -e ignores any failed return status of a single in a compound command. Bash Exit Script With Error Code add a comment| 1 Answer 1 active oldest votes up vote 237 down vote accepted Maybe you want set -e: http://www.davidpashley.com/articles/writing-robust-shell-scripts.html#id2382181 share|improve this answer answered Aug 13 '10 at 6:50 Alok Bash Exit Status Variable ls | bogus_command # bash: bogus_command: command not found echo $? # 0 # Note that the !

Script: #!/bin/bash touch /root/test 2> /dev/null if [ $? -eq 0 ] then echo "Successfully created file" else echo "Could not create file" >&2 fi In the above revision of our http://waspsoft.com/bash-exit/bash-exit-on-any-error.html The problem with the script was that it did not check the exit status of the cd command before proceeding with the rm command. Is the standard Canon 18-55 lens the same as 5 years ago? The next approach we can try is to use the if statement directly, since it evaluates the exit status of commands it is given. Bash Exit 0

Why are some programming languages Turing complete but lack some abilities of other languages? UNIX is a registered trademark of The Open Group. Not the answer you're looking for? navigate here exit $?

#!/bin/bash COMMAND1 . . .

Be atomic Sometimes you need to update a bunch of files in a directory at once, say you need to rewrite urls form one host to another on your website. Bash If Exit Code up vote 234 down vote favorite 49 I'm writing a script in Bash to test some code. Integral using residue theorem complex analysis How to increase the population growth of the human race How does the pilot control the Dassault Rafale?

command; then echo "command failed"; exit 1; fi What if you have a command that returns non-zero or you are not interested in its return value?

Execution: $ ./tmp.sh touch: cannot touch '/root/test': Permission denied $ echo $? 1 As you can see, since the last command run was touch the exit code reflects the true status Well-behaved UNIX commands, programs, and utilities return a 0 exit code upon successful completion, though there are some exceptions.

Likewise, functions within a script and the script try uses the || (boolean OR), which only evaluates the right side if the left one didn’t fail. $@ is all arguments again, but different. Bash Exit Script From Function Activate Hearthstone season chest cards?

Problem with using pause and onslide in one frame In a GNU C macro envSet(name), what does (void) "" name mean? Browse other questions tagged bash or ask your own question. You can call me old-school to prefer a while-loop rather than a for-loop for two conditions, but I find it better to read: i=1 RET=-1 while [ $i -le 5 ] http://waspsoft.com/bash-exit/bash-exit-on-error-script.html Each time expr2 evaluates to a non-zero value, list is executed and the arithmetic expression expr3 is evaluated.

I accepted a counter offer and regret it: can I go back and contact the previous company? Exit status As you recall from previous lessons, every well-written program returns an exit status when it finishes. 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. If any expression is omitted, it behaves as if it evaluates to 1.

You can see this work with the following: [me] $ true; echo $? 0 [me] $ false; echo $? 1 The true and false commands are programs that do nothing except Integral using residue theorem complex analysis Video displays in Star Wars Is the standard Canon 18-55 lens the same as 5 years ago? The solution to this is to make the changes an (almost) atomic operation. Video displays in Star Wars A simple visual puzzle to die for Skipping directly to level 4 What does Sauron need with mithril?

Now I know my ABCs, won't you come and golf with me? inverts the exit status returned. Lastly, note that set -o errexit can be full of surprises. This stops at the first for-iteration right after the false command: ( set -e; for (( i=1; i<5; i++ )); do echo $i; false; echo "${i}.

The disadvantage of this technique is that you need to use twice as much disk space and that any process that keeps files open for a long time will still have Related 2103Check if a directory exists in a shell script2882Can a Bash script tell which directory it is stored in?238Exit Shell Script Based on Process Exit Code721How do I prompt for That does not affect errexit at all. true !true # No error this time, but no negation either. # It just repeats the previous command (true). # =========================================================== # # Preceding a _pipe_ with !

It behaves bad even without the arithmetic test!