Sort source files with its lines.

short_files.sh

#!/usr/bin/env bash
if [ "$1" ]; then
    cd "$1" || exit
fi

exts="*.[ch]"
dirs=$(ls -d -- */ 2>/dev/null)
if [ "${dirs}" ]; then
    for d in ${dirs}; do
        count=0
        for f in $(find "$d" -type f -name "${exts}"); do
            lines=$(wc -l "$f" | cut -f1 -d" ")
            count=$((count + lines))
        done

        echo "$count: $d"
    done
else
    for f in $(find . -type f -name "${exts}"); do
        lines=$(wc -l "$f" | cut -f1 -d" ")
        echo "$lines: $f"
    done
fi | sort -n