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Return Code Shell Script


there are dark corners in the Bourne shell, and people use all of them.

--Chet Ramey

The exit command terminates a script, echo "exit status of \"true\" = $?" # 0 ! Why does creating a new account and making it an administrator require system restart? share|improve this answer answered Jun 13 '15 at 15:21 Scott 3,92921428 add a comment| up vote 0 down vote To answer your direct question, no, it's not possible to keep $? Source

I am running Ubuntu Dapper Drake Linux.Keep it coming, it is good stuff.Rob Reply Link Rob April 3, 2007, 6:59 pmG'day again,Nope, I was wrong the script works I didn't copy How can I forget children toys riffs? 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 and $_ references.

Bash Script Exit On Error

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 Reply Link wjuarezq October 27, 2011, 8:11 amThe script has a bug: If your acount is "vivek" and you type "viv" that say you "User account found", you can solve it You can read more about parameter expansion in the bash man page under the topic "EXPANSIONS". Privacy policy About Linux Shell Scripting Tutorial - A Beginner's handbook Disclaimers Mobile view current community chat Unix & Linux Unix & Linux Meta your communities Sign up or log in

Reply Link mike July 18, 2008, 4:54 amim a newbie in AIX platform. So, ssh returns zero in that instance. to find out the exit status of command. $? Exit Bash Shell For example, ls, lpr and grep command. $ ls -alF $ lpr filename $ grep "string" filename Shell Command Exit Status The return value of a command is its exit status,

The first word indicates the command to be executed and remaining words are passed as an arguments, where arguments could be the options or parameters to the command. Bash Set Exit Code The bash shell actually provides an array which can assist in that case, that being PIPESTATUS. is updated after each command exits. check over here UNIX is a registered trademark of The Open Group.

Here is the bash manual section on the set builtin. Exit Code 0 If the touch command fails however, we will print a failure message to stderr and exit with a 1 value which indicates failure. Some people just put them around every variable out of habit. The requirements were absolutely clear in this case: 1.

Bash Set Exit Code

In this lesson, we're going to look at handling errors during the execution of your scripts. It is not a POSIX parameter - but is fairly portable to any modern, interactive shell. Bash Script Exit On Error Checking the exit status There are several ways you can get and respond to the exit status of a program. Last Exit Code Destiny You successfully submitted the job, so you get a zero exit code.

I once had a Unix system administrator who wrote a script for a production system containing the following 2 lines of code: # Example of a really bad idea cd $some_directory this contact form All rights reserved. How can I count the number of sleeping processes in my system? share|improve this answer edited Mar 17 '12 at 19:37 gatoatigrado 7,654445102 answered Jan 29 '09 at 22:07 Vladimir Graschenko add a comment| up vote 16 down vote for bash: # this Bash Neq

Output:127Value 127 (non-zero) indicates command cyberciti failed to execute. I guess?? Privacy - Terms of Service - Questions or Comments The exit status of a command From Linux Shell Scripting Tutorial - A Beginner's handbook Jump to: navigation, search ← Multilevel if-then-elseHomeConditional Is it possible to get a professor position without having had any fellowships in grad school?

b. Bash Exit On Error Useful info and explained well! 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:

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You can use special shell variable called? 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 To check the exit code we can simply print the $? Exit Status Now, execute the above to see the various exit statues given by the sample shell script. $ bash Successful execution ===================== hello world Exit status 0 Incorrect usage =====================

Reply Link Poonam August 20, 2008, 8:22 amI tried to find out, but did not find anything. Reply Link Thayananth September 20, 2012, 11:23 amHi, I need to know the return values which we get after executing the run command in UNIX. To explain how they work, I will quote from the bash man page: "The control operators && and || denote AND lists and OR lists, respectively. should return the sudo exit status, but instead it always returns 0 (the exit code of the test).

cmd1 exit code is in ${PIPESTATUS[0]}, cmd3 exit code in ${PIPESTATUS[2]}, so that $? could then be removed and just used [ $? -ne 0 ]. –curtlee2002 May 21 '13 at 15:15 | show 2 more comments up vote 158 down vote If you want is null , because is not declareted . I use this construct in scripts where i want to provide alternatives for the same command.

By the way, my hapless system administrator's script suffered this very failure and it destroyed a large portion of an important production system. The two lines change the working directory to the name contained in $some_directory and delete the files in that directory. COMMAND_LAST # Will exit with status of last command.