Simple bash script help

Shell Programming and Scripting
1

Hi to everyone here,
I'm a new user and relatively-new linuxer.

I'm trying to write a script that checks if every file from a directory is present in a given list and if not, delete it.
should be simple. But I think I've done half the work only:

this is to create the reference list:

for c in `ls ~/cache`; 
    do for s in `ls ~/sel`;
        do case $c in
            $s) echo $s >> ~/installed;;
        esac 
    done
done

Now I'm not able to check again every file in the "cache" with the "installed" list and eventually delete them.

Every help is much appreciated,
thanks!

2 
# create a catalog list of files and directories you want to keep
# create a listing of files and directories in a given path

ls -1 > ../temp_list    # place list of dirs and files out of current working directory
cat ../catalog >> ../temp_list    # append dirs and files in the catalog list to the temp buffer file

sort ../temp_list | uniq -u | xargs rm -r    # delete anything is not in catalog
3

Thank you for the reply!
I'm not really sure of what you mean with "catalog", but the main thing is that I have to figure out what "uniq" and "xargs" commands do.

In the meantime, in my way, I accomplished the task; maybe it's not so elegant, but at least it works! :stuck_out_tongue:

#!/bin/bash

tot1=`ls /var/cache/apt/archives | grep -c deb`

echo apt-get autoclean...
sleep 1
sudo apt-get autoclean

echo installed packages back-up...
sleep 1
cd /var/cache/apt/archives
sudo mkdir cache-backup

for c in `ls | sed 's/_.*//'`; 
    do for s in `dpkg --get-selections`;
        do case $c in
            $s) echo backing-up $c && sudo cp -r $c*deb --target-directory=cache-backup;
        esac 
    done
done

sleep 1
tot2=`ls /var/cache/apt/archives | grep -c deb`
bup=`ls /var/cache/apt/archives/cache-backup | grep -c deb`
echo ---------------------------
echo "total packages in cache were: $tot1"
echo "packages after auto-cleaning: $tot2"
echo "installed packages to retain in cache: $bup"
echo ---------------------------
sleep 2
echo removing entire cache...
sudo rm *.deb
sleep 2

echo restoring backed-up packages...
sudo cp /var/cache/apt/archives/cache-backup/*.deb /var/cache/apt/archives
sudo rm -r /var/cache/apt/archives/cache-backup
sleep 2

echo closing...
sleep 2
exit

...all stuffed with a lot of useless echoes, since I know exactly what the script does: removing from the cache in "/var/cache/apt/archives" all not installed packages.