@Ignacio Larrain, I'd add a -F to that grep (i.e. grep -vF), because without that, . would be taken as a placeholder for "any character". Wouldn't be too important in that case, though ;). Also are you sure his isn't a race condition or something? It looks quite dangerous as it's reading from and writing to the same file. Maybe the safer thing to do would be:
@Ignacio Larrain, I'd add a -F to that grep (i.e. grep -vF), because without that, . would be taken as a placeholder for "any character". Wouldn't be too important in that case, though ;). Also are you sure his isn't a race condition or something? It looks quite dangerous as it's reading from and writing to the same file. Maybe the safer thing to do would be:
sed -i '/packages\ .medibuntu\ .org/d' /etc/hosts
Florian