Re: Removing backup files corresponding to no longer existing files

["Pascal J. Bourguignon" <pjb@informatimago.com>]

Rasmus Villemoes <burner+usenet@imf.au.dk> writes:

> Hi,
>
> I use a couple of separate directories to store emacs backup files
> (using backup-directory-alist). But this means that if I decide to
> delete or move some project (which is in its own direcory), just
> deleting or moving the directory leaves all the backup copies
> behind. They will then stay in the backup directories forever.
>
> Is there a way to tell emacs to remove backup files which no longer
> correspond to an actual file?
>
> It's probably not very difficult to write a little (shell/perl) script
> to do this, but I was wondering if there is some builtin way which
> I've overlooked.
>
> Emacs 23.1.1 on Ubuntu 10.10, if it matters.

I have:

-----(clean-old-versions)-----------------------------------------------
#!/bin/bash 
dirs=()
do=
for arg ; do 
    case "$arg" in
    -n) do=echo ;;
    -*) echo "Usage:"
        echo "   $(basename $0) [-n] [directory ...]"
        echo "Remove all backup files that don't have a head."
        echo "If no directory is specified, then clean the current directory." 
        echo "-n only shows what would be done."
        exit 1
        ;;
    *)  dirs[${#dirs}]="$arg" ;;
    esac
done
if [ ${#dirs[@]} -eq 0 ] ; then
    dirs=(.)
fi
for dir in "${dirs[@]}" ; do 
    find "$dir" -maxdepth 1 \( -name \*~ -o -name .\?\*~ \) -print  \
    |while read file ; do 
        base="$(echo "$file" | sed -e 's/\(\.~[.0-9]\+\)\?~$//')"
        if [ ! -e "$base" ] ; then
            $do rm -v "$file" 
        fi
     done
done
------------------------------------------------------------------------

Indeed, it wouldn't be too hard to write it in emacs lisp either.  
The question would be when to run it?

-- 
__Pascal Bourguignon__                     http://www.informatimago.com/
A bad day in () is better than a good day in {}.