error in a backup script

adam_blackice · 08-25-2007, 10:58 AM

hello all i want to make a bash script that backup files from a dir to another dir ..., by the way here is the script ...

Code:

 #!/bin/bash


backupdir=/home/blackice/Desktop/backup

scriptdir=/home/blackice/Desktop/scripts

backupfile=scripts.backup.`date +%F`

tar -czvf $backupdir $backupfile $scriptdir


#end

when ever i run it i got the following error

Code:

[root@localhost backup]# ./backupscripts.sh 
tar: /home/blackice/Desktop/backup: Cannot open: Is a directory
tar: Error is not recoverable: exiting now
tar: scripts.backup.2007-08-25: Cannot stat: No such file or directory
tar: Removing leading `/' from member names/home/blackice/Desktop/scripts/
/home/blackice/Desktop/scripts/network/
/home/blackice/Desktop/scripts/network/internet_status.sh
/home/blackice/Desktop/scripts/network/insist_ping.sh
/home/blackice/Desktop/scripts/network/watching_network_service.sh
/home/blackice/Desktop/scripts/loops/
/home/blackice/Desktop/scripts/loops/until_loop.sh
/home/blackice/Desktop/scripts/loops/for_loop.sh
/home/blackice/Desktop/scripts/loops/while_loop.sh~
/home/blackice/Desktop/scripts/loops/while_loop.sh
/home/blackice/Desktop/scripts/backup/
/home/blackice/Desktop/scripts/backup/backupscripts.sh
/home/blackice/Desktop/scripts/users/
/home/blackice/Desktop/scripts/users/logins.sh
/home/blackice/Desktop/scripts/Directories/
/home/blackice/Desktop/scripts/Directories/check_for_dir.sh~
/home/blackice/Desktop/scripts/Directories/test/
/home/blackice/Desktop/scripts/Directories/loop_in_dir.sh
/home/blackice/Desktop/scripts/Directories/check_for_dir.sh
/home/blackice/Desktop/scripts/Directories/loop_throw_users_project/
/home/blackice/Desktop/scripts/Directories/loop_throw_users_project/illustration
/home/blackice/Desktop/scripts/Directories/loop_throw_users_project/illustration~
/home/blackice/Desktop/scripts/Directories/loop_throw_users_project/loop_in_users.sh
/home/blackice/Desktop/scripts/processes/
/home/blackice/Desktop/scripts/processes/control_jobs.sh
/home/blackice/Desktop/scripts/processes/junkdata.data
/home/blackice/Desktop/scripts/processes/junk1.data

ghostdog74 · 08-25-2007, 11:15 AM

check your tar syntax...

adam_blackice · 08-25-2007, 11:39 AM

thanx for replay
but iam sure of the syntax ....... ? !

druuna · 08-25-2007, 11:48 AM

Hi,

tar -czvf $backupdir $backupfile $scriptdir

will translate into:

tar -czvf /home/blackice/Desktop/backup scripts.backup.2007-08-25 /home/blackice/Desktop/scripts

Which doesn't look correct.

Code:

#!/bin/bash

set -x

backupdir=/home/blackice/Desktop/backup

scriptdir=/home/blackice/Desktop/scripts

backupfile="${scriptdir}/scripts.backup.`date +%F`.tgz"

tar -czvf $backupfile $scriptdir

tar -czvf $backupfile $scriptdir

will now translate to:

tar -czvf /home/blackice/Desktop/scripts/scripts.backup.2007-08-25.tgz /home/blackice/Desktop/scripts

Hope this helps.

adam_blackice · 08-25-2007, 12:56 PM

thanks it works !

but i have questions what is the use of ${scriptdir}? itis something like function in braces ?

and thanks again

also the tar making this error

tar: Removing leading `/' from member names
?

druuna · 08-25-2007, 02:24 PM

Hi,

Quote:

what is the use of ${scriptdir}?

$scriptdir and ${scriptdir} are basically the same, but sometimes you need the curly braces to do some bash related stuff (man bash -> Parameter Expansion).

I made it a habit to always use the curly braces.

Here's another reason why you need to use culry braces:

dirpart="/x/y/z/"
file1=${dirpart}somename.datestamp.extension
file2=$dirpartsomename.datestamp.extension

file1 will be what you wanted (=> /x/y/z/somename.datestamp.extension)
file2 will be empty, there's no variable called dirpartsomename.datestamp.extension.

Quote:

tar: Removing leading `/' from member names

This is tar's default behavior. Without the leading /, it is possible to extract the archive at any location and select yourself what file(s) needs to be restored. If the leading slash is not removed, untarring will overwrite the files that are already there (which could be good, but is a bad thing most of the time).

The -p / --absolute-names option will make sure that the leading / won't be removed (only use this if you know what the consequences are....)

Hope this helps.

adam_blackice · 08-25-2007, 04:30 PM

really thanx for your brief explain.