Shell Programming and Scripting

I have a script as below , the script can tar file to the tape , however , it is fail to handle the error , if there is error like the backup file is in writing , then it will echo this is fail ( but the file has successful backup actually , so the backup task is succes , but it still report it is fail ) , can advise how to modify it so that if all files are backup , then echo this is success ? thanks

Code:

tar -zcvf /dev/st0 ...
if [ $? -eq 0 ] ;
	then echo this is success
else 
 echo this is fail

fi

So there's an error in the backup file, but you don't care about it, because it's not inside files you care about...?

I still think that's a cause for concern.

Better to fix the error than try to selectively ignore them. You'll end up ignoring errors you shouldn't and land in real trouble.

So there's an error in the backup file, but you don't care about it, because it's not inside files you care about...? ==> I think the output messages is only for alert , as the backup is complete , I think it can be ignore.

I still think that's a cause for concern.

Better to fix the error than try to selectively ignore them. You'll end up ignoring errors you shouldn't and land in real trouble.

==> the error is not easy to fix , as the files is always writing ( this is system log file ) , therefore , the "message" is presist. is there any better way to modify the script , so that it can ignore such messages , can kindly advise the backup script ?

thanks.

You can instruct tar to not try and archive that file with -X, which reads a list of filenames to ignore.

Code:

echo filename-to-ignore > /tmp/exclude-list

tar -X /tmp/exclude-list ...

rm -f /tmp/exclude-list

Dude, you've been posting on Linux forums since 2003....and youv'e asked this question before. don't you understand what folks tell you?

-X seems will exclude to backup the file , if I just want to backup the file but exclude the error only , is it ok ?

thanks

It's warning you about backing up a file that's being written to because that's really a no-no. You really need to cooperate with whatever's creating the logfile here. Can you stop the service while the backup is happening, or at least lock the file temporarily?