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Bash Evaluate Return Code


true\" = $?" # 1 # Note that the "!" needs a space between it and the command. # !true leads to a "command not found" error # # The '!' command1; then share|improve this answer edited Sep 23 '16 at 17:57 answered Jul 10 '15 at 18:37 dimo414 21.7k778123 3 Thanks for the if ! special variable to print the exit code of the script. Sample Output: 0 Try non-existence command date1 echo $? http://computerhelpdev.com/exit-code/bash-get-return-code.php

Browse other questions tagged bash exit or ask your own question. Publications Red Hat Enterprise Linux Troubleshooting Guide Identify, capture and resolve common issues faced by Red Hat Enterprise Linux administrators using best practices and advanced troubleshooting techniques What people are saying: Combined with OR the bash should only invoke exit, if the previous command fails. Otherwise, && is skipped, and echo "NOK" is executed. http://stackoverflow.com/questions/90418/exit-shell-script-based-on-process-exit-code

Bash Set Exit Code

By not defining proper exit codes you could be falsely reporting successful executions which can cause issues depending on what the script does. I don't want to have to do something like: command1 if [ $? -ne 0 ]; then echo "command1 borked it" fi command2 if [ $? -ne 0 ]; then echo lskdf # Unrecognized command. While this is a working solution to the problem, there are more clever methods that will save us some typing.

Script: #!/bin/bash touch /root/test If we remove the echo command from the script we should see the exit code of the touch command. Testing for exit codes Earlier we used the $? share|improve this answer edited Sep 18 '08 at 6:20 answered Sep 18 '08 at 6:10 Jeff Hill 41.8k3116 1 This should really be the top answer: it's much, much easier Last Exit Code Destiny is always the same as ${PIPESTATUS: -1}. ...

Checking the exit status There are several ways you can get and respond to the exit status of a program. Any link to docs please? –Swaroop C H Sep 18 '08 at 6:15 1 @SwaroopCH set -e your script will abort if any command in your script exit with error By the way, my hapless system administrator's script suffered this very failure and it destroyed a large portion of an important production system. http://stackoverflow.com/questions/17573312/how-to-use-bash-return-code-in-conditional 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

Can anyone suggest what should I do here ? Exit Code 0 This becomes especially true if the script is used with automation tools like SaltStack or monitoring tools like Nagios, these programs will execute scripts and check the status code to determine Does every data type just boil down to nodes with pointers? After a function returns, $? gives the exit status of the last command executed in the function.

Bash Neq

Are there any rules of thumb for the most comfortable seats on a long distance bus? http://www.tldp.org/LDP/abs/html/exit-status.html Please use the new version at LinuxCommand.org LinuxCommand Learningtheshell Writingshellscripts Script library SuperMan pages Who, What, Where, Why Tips, News And Rants Previous | Contents | Next Errors and Signals and Bash Set Exit Code Typically, you only need to use it when you want to save its value before running another command: valid_ip "$IP1" status1=$? Bash Script Exit On Error RETURN, but that's up to you to investigate.

list of files based on permission Generalization of winding number to higher dimensions Only part of texture paint is pink Why are Zygote and Whatsapp asking for root? this page I never succeed in thickening sauces with pasta water. Kids shuffling cards Why would two species of predator with the same prey cooperate? could then be removed and just used [ $? -ne 0 ]. –curtlee2002 May 21 '13 at 15:15 | show 2 more comments up vote 159 down vote If you want Exit Bash Shell

Using parameter expansion, it is possible to perform a number of useful string manipulations. more stack exchange communities company blog Stack Exchange Inbox Reputation and Badges sign up log in tour help Tour Start here for a quick overview of the site Help Center Detailed variable so you would have something like: ls -al file.ext rc=$?; if [[ $rc != 0 ]]; then exit $rc; fi You need to be careful of piped commands since the http://computerhelpdev.com/exit-code/bash-last-return-code.php The variables are $BASH_LINENO and $BASH_COMMAND.

directly. Bash Exit On Error Is there any way to take stable Long exposure photos without using Tripod? The list constructs use exit codes to understand whether a command has successfully executed or not.

valid_IP should return 0 if the IP address is valid, and 1 otherwise. –chepner Jul 10 '13 at 15:25 add a comment| up vote 5 down vote No parentheses needed if

You can optionally set the $LOG_STEPS variable to a log file name if you want to log which commands fail. But I haven't tested this. Execution: $ ./tmp.sh Could not create file Providing your own exit code While the above revision will provide an error message if the touch command fails, it still provides a 0 Exit Code 1 RedHat tends to maintain backwards compatibility for long, which is why the init.d stuff is still there. –dragon788 Feb 13 '16 at 16:06 add a comment| up vote 36 down vote

error_msg="ERROR : Failed to run the command \"$cmd\" with the output \"$msg\" !!!" [ $ret_cmd -eq 0 ] || doLog "$error_msg" doLog " DEBUG : cmdoutput : \"$msg\"" } #eof func unnecessary: # Better if grep -q regex options; then # Do nothing : else printf '%s\n' 'myscript: Pattern not found!\n' >&2 exit 1 fi We can precede the command to be 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://computerhelpdev.com/exit-code/return-code-126-bash.php This will save more typing and promote laziness. # An error exit function function error_exit { echo "$1" 1>&2 exit 1 } # Using error_exit if cd $some_directory; then rm *

more hot questions question feed lang-sh about us tour help blog chat data legal privacy policy work here advertising info mobile contact us feedback Technology Life / Arts Culture / Recreation You usually want something like if ls -al file.ext; then : nothing; else exit $?; fi which of course like @MarcH says is equivalent to ls -al file.ext || exit $? You can read more about parameter expansion in the bash man page under the topic "EXPANSIONS". If those conditions are true, then check whether or not it has a size greater than 0. #!/bin/bash echo "Which error log are you checking today? " read answer if [

Extreme modification suggestions for a Wi-Fi enabled hairbrush? We can also use this variable within our script to test if the touch command was successful or not.