Backup script

[nasser00]

Hey there,

I'm attempting to create a shell script using Ubuntu that will take one optional argument (which in this case is a path to a directory to backup) and will back up (by using the tar command) the chosen directory which is the /home. And i want, after tar'ing the home directory, for it to save the output in /var/backups with the file name as the date.

I'm very new to this so I was just hoping I could get pointed in the right direction!

Cheers.

[Lakshmipathi]

Hi Welcome !

Since you want direction rather than code check out this link for bash shell programming (with list of examples) Advanced Bash-Scripting Guide

Learning bash will be very useful - Hope this helps

If you stuck some where with your program,post it here.

[egan]

What exactly do you need direction for? I assume you know how to tar things and move them to other directories? Is it just the argument handling that is new for you?

[nasser00]

Yup the arguements are something im not familar with

[egan]

Yup the arguements are something im not familar with

Well if you name your program 'backup', and you want to call it like: backup /home to backup the home directory, then you will need to use positional arguments. They are referenced as $X where X is a number.

$0 is the name of the program, i.e. backup
$1 for you will be the directory to backup...
$2 would be extra...

To count the number of arguments (not including $0), you use $#. So you would want to check to make sure that the number of arguments is correct.

if [ -z $1 ]
then
         echo "Error: Too few arguments"
         echo "Usage -- $0 [dirtobak]"
fi

to check if $1 is empty

if [ $# -gt 2 ]
then
          echo "Error: Too many arguments"
          echo "Usage -- $0 [dirtobak]"
fi

to check if there are extra arguments.

Once you have determined that the arguments were syntactically correct, you have to determine if they are valid. Since you expect $1 to be a directory, you'll want to make sure it isn't anything else.

if [ ! -d $1 ]
then
         echo "Error: Invalid directory $1"
         echo "Usage -- $0 [dirtobak]"
fi

to check if $1 isn't a directory.

Hopefully this will give you some help...

[nasser00]

Cheers for your help everyone im sure im heading in the right direction now and stuff seems to be coming along!