Salut,

Dans la même veine que rtorrent-cleaner pour r(u)torrent, j'ai trouvé un script pour faire du ménage dans les fichiers non-supprimés par Transmission

#!/bin/bash

# get a list of all torrents transmission-remote 2.52
transmission-remote --auth user:pass -t all --files > _all_torrents.tmp

# all items in this directory
for i in *
do
        # is it a file or a directory
        if test -f "$i" -o -d "$i"
        then
                # does it NOT exist in the list of all torrent files
                #if [[ $all_files != *"$i"* ]]
                if ! grep -Fq "$i" _all_torrents.tmp
                then
                        # does it not start with an underscore (my special char for files in directory not related to transmission
                        if [[ "$i" != _* ]]
                        then
                                # delete them
                                echo rm -rf \"$i\"
                                # rm -rf "$i"
                        fi
                fi
        fi
done

# clear tmp file
rm _all_torrents.tmp

source : https://unix.stackexchange.com/a/371869