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Bash Script Error Code

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On top of those reasons, exit codes exist within your scripts even if you don't define them. If you add a -p option then mkdir will create all the parent directories before creating the requested directory. Problem? 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. Check This Out

if [ $filename = "foo" ]; will fail if $filename contains a space. An advantage is that you now have a backup before you made your changes in case you need to revert. © 2013 Company Name Adopt A Jet/Book Is 8:00 AM an unreasonable time to meet with my graduate students and post-doc? E.g., I would like to do: command -p sudo ... [ $? -ne 1 ] && exit $?

Shell Script Return Code

How's the CMD trip bonuses from extra legs work? In our example this isn't a problem as apache opens the files every request. There are another couple of things to fix, I'm waiting he posts some lines of the source file. –Hastur Jun 16 '14 at 12:28 1 The issue with capturing the Activate Hearthstone season chest cards?

This tells bash that it should exit the script if any statement returns a non-true return value. Also, just to be clear, command won't test for the location of any arguments to sudo - so it is only sudo - and nothing it invokes - which is relevant No need to repeat your (IMO wrong) opinion here, or start another iteration of the dispute. –Janis Jun 14 '15 at 7:04 1 @mikeserv; The expansion side effects in the Bash Script Error Output If you would like this to fail, then you can use set -o pipefail to make it fail.

I know I have, many times. in (1) ... ;; (127) ... ;; (*) echo $? ;; esac with the special case asked in the question: command -p sudo ... It is not a POSIX parameter - but is fairly portable to any modern, interactive shell. Join them; it only takes a minute: Sign up In bash, how to set a return code?

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 $? Bash Script Error Log value in a variable if you want to reference it more than once. 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 share|improve this answer edited Jun 13 '15 at 17:05 eadmaster 351414 answered Jun 13 '15 at 14:34 llua 3,582716 1 Valid for this particular example, but only usable if there

  1. And so anyway, if that is what you're trying to do: command -pv sudo >/dev/null || handle_it command -p sudo something or another ...would work just fine as a test without
  2. To explain how they work, I will quote from the bash man page: "The control operators && and || denote AND lists and OR lists, respectively.
  3. share|improve this answer edited Sep 18 '08 at 6:20 answered Sep 18 '08 at 6:10 Jeff Hill 39.8k3116 Works like a charm! –Joseph Lust Apr 30 '14 at 16:04
  4. changes things: > cat tst.sh #!/bin/bash ping nosuchhost [ $? -ne 1 ] && exit $? > ./tst.py ping: unknown host nosuchhost 0 Yes, the 2nd reference to $?
  5. share|improve this answer answered Jun 13 '15 at 15:21 Scott 3,75821328 add a comment| up vote 0 down vote To answer your direct question, no, it's not possible to keep $?
  6. In this case, the last run command is the echo command, which did execute successfully.
  7. Verbatim copying and distribution of this entire article is permitted in any medium, provided this copyright notice is preserved.
  8. This is Bash's way of giving functions a "return value." [1]

    Following the execution of a pipe, a $? gives the exit status of
  9. no outgoing connection via ipv4 Please explain the local library system in London, England A name for a well-informed person who is not believed?
  10. Another example to clarify further: spd-say "[email protected]" [ $? -ne 127 ] && exit $?

Unix Exit Command In Shell Script

Which requires more energy: walking 1 km or cycling 1 km at the same speed? It is generally safer to use read -r than read. -r raw input - disables interpretation of backslash escapes and line-continuation in the read data so a code variant should be: Shell Script Return Code The problem with temporary variables is that they could shadow other variables, and to avoid that you must use long names, which is not good for code readability. Bash Script Error Checking rc=$? [ "$rc" -ne 1 ] && echo "$rc" You can directly check success or failure: if command -p sudo ...

Previous | Contents | Top | Next © 2000-2016, William E. http://sovidi.com/bash-script/bash-script-capture-error-code.php share|improve this answer edited May 4 '12 at 13:19 answered May 4 '12 at 11:46 unwind 253k38330460 A command guaranteed to fail is wanted here: false. –chepner May 4 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 IMHO it's better to stick to a consistent method which works in other cases (and can also help with the code readability). –Dan Cornilescu Jun 13 '15 at 15:46 4 Bash Script Error Command Not Found

What happens if I don't specify an exit code In Linux any script run from the command line has an exit code. Now I know my ABCs, won't you come and golf with me? Actions such as printing to stdout on success and stderr on failure. this contact form Nor was portability mentioned anywhere in the question, thus i gave a answer that works in said shell.

If those answers do not fully address your question, please ask a new question. Bash Script Error Message eval '[ "$?" = 127 ] || exit '"$?" Which basically allows you to expand the initial value for $? Exit Codes With Special Meanings

Table E-1.

Execution: $ ./tmp.sh touch: cannot touch '/root/test': Permission denied created file $ echo $? 0 As you can see after running the ./tmp.sh command the exit code was 0 which indicates

I guess the problem is that invoking sudo as part of the test allows for sudo squashing the return of command in the first place and so skewing the test. –mikeserv Reserved Exit Codes

Exit Code NumberMeaningExampleComments1Catchall for general errorslet "var1 = 1/0"Miscellaneous errors, such as "divide by zero" And press return when you want to go forward –Hastur Jun 16 '14 at 11:51 please post some lines from copy_new_files.tmp. –Hastur Jun 16 '14 at 12:07 Bash Script Error Handling Trap An OR list has the form command1 || command2 command2 is executed if, and only if, command1 returns a non-zero exit status.

It seems like exit codes are easy for poeple to forget, but they are an incredibly important part of any script. share|improve this answer answered Jun 13 '15 at 15:00 Dan Cornilescu 77616 What value does your Python script add to this answer? –G-Man Jun 13 '15 at 15:27 This can be fixed by using: if [ "$filename" = "foo" ]; When using [email protected] variable, you should always quote it or any arguments containing a space will be expanded in http://sovidi.com/bash-script/bash-script-error-code-checking.php not in ksh). - My proposals are standard and work in bash (mostly used on Linux) and ksh (the predominating shell in commercial Unixes). –Janis Jun 17 '15 at 5:36 |

asked 1 year ago viewed 5673 times active 1 year ago Related 10Bash script to detect the version control system by testing command return status2how to detect if command execute failed When was this language released? In this article, I explain several techniques for writing robust bash scripts. asked 2 years ago viewed 381 times active 2 years ago Linked 215 bash: pipe output AND capture exit status Related 2882Can a Bash script tell which directory it is stored

What other weird restrictions are going to be made up? –llua Jun 13 '15 at 18:03 1 @mikeserv; In case you missed it: I said: "There was a very first command -p sudo; then exit; fi which would have the same results for your example. –jordanm Jun 13 '15 at 13:44 ok, what if i want to test for