You can use $? Thanks very much. What am I doing wrong? COMMAND_LAST # Will exit with status of last command.
share|improve this answer edited Jan 7 '16 at 1:24 answered Sep 18 '08 at 6:08 paxdiablo 505k1229991454 32 Same feature in just one line of portable code: ls -al file.ext in (1) ... ;; (127) ... ;; (*) echo $? ;; esac with the special case asked in the question: command -p sudo ... share|improve this answer answered Sep 18 '08 at 6:11 Arvodan 6873819 add a comment| up vote 20 down vote http://cfaj.freeshell.org/shell/cus-faq-2.html#11 How do I get the exit code of cmd1 in cmd1|cmd2 Shotts, Jr. https://www.cyberciti.biz/faq/shell-how-to-determine-the-exit-status-of-linux-and-unix-command/
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 Is an animated corpse with a weapon overpowered? Actions such as printing to stdout on success and stderr on failure.
if [ $RESULT -eq 0 ]; then echo success else echo failed fi if [ $RESULT == 0 ]; then echo success 2 else echo failed 2 fi share|improve this answer Here is an illustration showing that if conditions may also be nested. Thanks for sharing, and thanks for the above comment. Bash Return Value From Function ls: cannot access filenotfound.txt… 2 $ ls filenotfound.txt & ls: cannot access filenotfound.txt… echo $? 0 + Exit 2 ls filenotfound.txtSame thing happens when you fork off a process.
In this lesson, we're going to look at handling errors during the execution of your scripts. Shell Script Exit Code true\" = $?" # 1 # Note that the "!" needs a space between it and the command. # !true leads to a "command not found" error # # The '!' true !true # No error this time, but no negation either. # It just repeats the previous command (true). # =========================================================== # # Preceding a _pipe_ with ! Reply Link saravanakumar June 12, 2011, 2:44 pmVery useful…thanks a lot…its makes me to understand about "$?".
Don't let this happen to you! Exit Code 0 no matchgrep foo /tmp/bar.txt || echo "text not found"# grep returns 0, e.g. Encryption - How to claim authorship anonymously? If EXPRESSION is a single argument, ‘test’ returns false if the argument is null and true otherwise." –Lekensteyn Mar 25 '16 at 18:31 | show 3 more comments up vote 38
July 31, 2012 at 11:59 AM Post a Comment Newer Post Older Post Home Subscribe to: Post Comments (Atom) Merry Christmas Merry Christmas Followers Subscribe in a reader Enter your email http://linuxcommando.blogspot.com/2008/03/how-to-check-exit-status-code.html Next, if command makes decision based upon exit status stored in OUT variable. Bash If Exit Code List constructs allow you to chain commands together with simple && for and and || for or conditions. Bash If Exit Code Not 0 It's probably the most common command to use in an if, which can lead to the assumption that it's part of the shell's syntax.
Why one shouldn't play the 6th string of an A chord on guitar? http://silkiconfinder.com/exit-code/return-code-in-unix-script.html 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 if [ $OUT -eq 0 ];then echo "User account found!" else echo "User account does not exists in /etc/passwd file!" fi#!/bin/bash echo -n "Enter user name : " read USR cut UNIX is a registered trademark of The Open Group. Bash Set Exit Code
Useful info and explained well! Should we eliminate local variables if we can? Are the following topics usually in an introductory Complex Analysis class: Julia sets, Fatou sets, Mandelbrot set, etc? his comment is here Which was the last major war in which horse mounted cavalry actually participated in active fighting?
What is the name of these creatures in Harry Potter and the Deathly Hallows? Exit Bash Shell If grep command finds user name in /etc/passwd command output it would return exit status of zero. Buy on Amazon Sponsored by Become a Sponsor Copyright © Benjamin Cane 2014 - Contact the Author Advanced Bash-Scripting Guide: PrevNext
But what if you embed the grep command in a script? Why one shouldn't play the 6th string of an A chord on guitar? 12 hour to 24 hour time converter Word for unproportional punishment? 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 Bash Not Equal up vote 76 down vote favorite 26 Is there any way to check if there is an error in executing a command?
share|improve this answer answered Mar 8 '11 at 23:54 geirha 22.4k84754 add a comment| up vote 9 down vote $? share|improve this answer answered Jun 13 '15 at 15:21 Scott 3,92621428 add a comment| up vote 0 down vote To answer your direct question, no, it's not possible to keep $? Also rc=$? weblink 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
Reply Link tuh July 12, 2011, 5:45 pmMaybe Chris will see this, or maybe not. This means that if you execute a pipeline, you'll only get the exit code of the last process in the pipeline. For example run command called cyberciti $ cyberciti Output:bash: cyberciti: command not foundDisplay exit status of the command: $ echo $? echo $? # Non-zero exit status returned -- command failed to execute.
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