what is the easy way to exclude folders in /home during backup

Question

I am doing backup using

for a in /home/*
do
//do backup
done

I want to exclude some folders in /home . but for loop takes all folders i there.

is there any way so that i can specify exclude list at top which can be used in loop

Answer 1

You need some sort of evaluation in order to check what to exclude from the list of folders you get in the "for"; just using bash this could be (you can use whatever you feel comfortable to evaluate what to exclude (ie sed, grep, awk,...)):

exclusiondirs="/home/foo /home/bar" # list of folders to exclude from backup

for a in /home/*; do
if ! [[ "$exclusiondirs" =~ $a ]]; then
    ...do backup...
fi
done

However I would have use some other tools for backup such rsync which can exclude by itself, for example:

rsync -av /home/* --exclude /home/foo --exclude /home/var destination

Edited:

Since the bash regex is a bit tricky and difficult to implement in some circumstances I've replaced it with a more robust grep statement:

if ! echo "$exclusiondirs" | grep -q "\b$a\b" ; then

This grep statement will work in a home dir with names such as (where some dirs share common part names and include spaces within):

mkdir -p home/{foo,bar,foobar,a,b,c,a\ b
tree
`-- home
    |-- a
    |-- a b
    |-- b
    |-- bar
    |-- c
    |-- foo
    `-- foobar

~$ echo $exclusiondirs 
/home/foo /home/bar /home/a
~$ for a in /home/*; do if ! echo "$exclusiondirs" | grep -q "\b$a\b" ; then echo $a; fi; done
/home/a b
/home/b
/home/c
/home/foobar

Answer 2

Go to Skipping multiple files and folders section in this page.