Remove Files Older Than X Days

find /path/to/folder -mtime +10 | xargs rm

• -mtime +10 — files older than 10 days

Other parameters

• -size 0 — files with size 0
• | grep -v pattern — invert match

Find file and edit the search

find path/to/files -mtime +1 -size 0 | grep .downloading | sed -e 's/\.downloading/\*/g' | xargs echo rm | sh

Modify the .downloading extension to * and remove all matches.