Source Multiple Files from Directory

# Source every .sh file in ~/.bashrc.d (alphabetical order)
if [[ -d "$HOME/.bashrc.d" ]]; then
    for f in "$HOME/.bashrc.d"/*.sh; do
        [[ -f "$f" ]] && source "$f"
    done
fi

# Same, but only readable files (defensive against broken permissions)
for f in "$HOME/.bashrc.d"/*.sh; do
    [[ -r "$f" ]] && . "$f"
done

# Source ALL the files but log which ones loaded (for debugging slow shell startup)
for f in "$HOME/.bashrc.d"/*.sh; do
    [[ -r "$f" ]] || continue
    t0=$EPOCHREALTIME
    . "$f"
    printf '%6.0f ms  %s\n' "$(echo "($EPOCHREALTIME - $t0) * 1000" | bc)" "$f"
done >&2