yes, apt-get can do that, and can do it in a nice way.

1. Append following to ~/.bash_funcs

   
   
   

   update-repo() {
   
       for source in "$@"; do
   
           sudo apt-get update -o Dir::Etc::sourcelist="sources.list.d/${source}" 
   
           -o Dir::Etc::sourceparts="-" -o APT::Get::List-Cleanup="0"    
   
       done
   
   }
   
   




2. Append following to ~/.bashrc

   
   
   

   if [ -f $HOME/.bash_funcs ]; then
   
   .  $HOME/.bash_funcs
   
   fi
   
   




3. Append following to ~/.bash_completion

   
   
   

   # Debian user-defined completion                             -*- shell-script -*-
   
   
   
   _ppa_lists(){
   
       local cur
   
       _init_completion || return
   
   
   
       COMPREPLY=( $( find /etc/apt/sources.list.d/ -name "*$cur*.list" 
   
   -exec basename {} ; 2> /dev/null ) )
   
       return 0
   
   } &&
   
   complete -F _ppa_lists update-repo
   
   




4. Then source the files

   
   
   

   . ~/.bashrc
   
   . ~/.bash_completion
   
   




5. Done and start to fire it

   
   
   

   update-repo <tab> <tab>
   
   

You can update a single ppa repository without having to update whole apt source, with implement of bash-completion.