Find duplicate files in a directory tree (recursively)

Based on md5sum differences

find . -type f -exec md5sum {} + | sed 's!.*/\(.*\)\.[^.]*$!\1|&!' | awk -F\| '{i=indices[$1]++;found[$1,i]=$2}END{for(bname in indices){if(indices[bname]>1){for(i=0;i<indices[bname];i++){print found[bname,i]}}}}'

Based on filename differences

find . -type f -print | sed 's!.*/\(.*\)\.[^.]*$!\1|&!' | awk -F\| '{i=indices[$1]++;found[$1,i]=$2}END{for(bname in indices){if(indices[bname]>1){for(i=0;i<indices[bname];i++){print found[bname,i]}}}}'

Using fdupes

fdupes -dSr dir