find
Search for files in a directory hierarchy.
$ find .
Examples
# Find by name
find . -name "*.txt"
# Find by type
find /var/log -type f -name "*.log"
# Find and execute
find . -name "*.tmp" -exec rm {} \;
# Find empty files
find . -type f -empty
# Limit depth
find . -maxdepth 2 -name "*.md"