Bash Exit Codes. Exit codes. There is a simple, useful idiom to make your bash scripts more robust - ensuring they always perform necessary cleanup operations, even when something unexpected goes wrong. Knowing how to use exit codes, options such as errexit, and traps allow you to create robust scripts and better handle errors in bash. You can also test the return code of a function which can be either an explicit return 3 or an implied return code which is the result of the last command, in this case you need to be careful that you don't have an echo at the end of the function, otherwise it masks/resets the previous exit code. Here is most generic and accepted exit status codes.exit code is used to state command or script execution is completed succesfully. So, if your exit code is 20, then the exit status is 236. If the cmd process exits(as in the case you run the exit command in the cmd window or use “exit exitCode” in a bat script), the exitcode will be set to the exit code of the cmd process. $ bash $ exit 261 exit $ echo $? This is the value returns to parent process after completion of a child process. To help explain exit codes a little better we are going to use a quick sample script. 2 exit code is used to state there is a misuse of the shell builtin. If the exit code is a negative number, the resulting exit status is that number subtracted from 256. This can actually be done with a single line using the set builtin command with the -e option. This behavior is not ideal as it causes the -e option to only be able to act on the exit code of a pipeline's last command. Shell script with -e. We can set the -e either on the sh-bang line or with the set -e command. In other words, it denotes the exit status of the last command our function. In the code, we have clearly mentioned that we if don’t find the file called lists.txt then we should set the errorlevel to 7. Exit When Any Command Fails. The exit code is a number between 0 and 255. How "Exit Traps" Can Make Your Bash Scripts Way More Robust And Reliable. For example if the last statement tries to create a directory with mkdir some/path, and the command fails, then the exit code of the script itself will be the exit code of the failed mkdir.. Similarly, if we see that the variable userprofile is not defined then we should set the errorlevel code to 9. if not exist c:\lists.txt exit 7 if not defined userprofile exit 9 exit 0 One of the things that the test.sh script does is stop the container after the Ansible run, but I was noticing that the script never ran the stop container function if the Ansible test failed because Ansible returned a non-0 exit code which triggered set -e. This is where -o pipefail comes in. The exit code value return based on a command … In Linux any script run from the command line has an exit code. With Bash scripts, if the exit code is not specified in the script itself the exit code used will be the exit code of the last command run. 1 exit code is used to state that there are general errors like divide by zero etc. 5 To produce an errant exit status of 0: $ bash $ exit 256 exit $ echo $? set -o pipefail The bash shell normally only looks at the exit code of the last command of a pipeline. Handling errors based on exit codes is the standstill method for detecting failure in a command. Not only that, but the whole script indicates success (its own exit code is set to be 0) even thought some part of it have failed. # exit when any command fails set -e Putting this at the top of a bash script will cause the script to exit if any commands return a non-zero exit code. 0 If you use 257 as the exit code, your exit status is 1, and so on. 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