Get a list of all dependencies, their sizes & how many apps use it

depstats.sh

#!/usr/bin/env bash
set -euo pipefail

# Colors for pretty output
GREEN="\033[0;32m"
YELLOW="\033[1;33m"
RESET="\033[0m"

declare -A deps_map
declare -A app_seen

get_binaries_from_desktop_files() {
    local desktop_dirs=(
        "/usr/share/applications"
        "/usr/local/share/applications"
        "$HOME/.local/share/applications"
    )

    local binaries=()
    for dir in "${desktop_dirs[@]}"; do
        [[ -d "$dir" ]] || continue
        while IFS= read -r line; do
            local exec_path
            exec_path=$(echo "$line" | sed -E 's/^Exec=([^ ]+).*/\1/' | sed 's/^"//;s/"$//')
            [[ -n "$exec_path" ]] && binaries+=("$exec_path")
        done < <(grep -h "^Exec=" "$dir"/*.desktop 2>/dev/null || true)
    done

    printf "%s\n" "${binaries[@]}" | sort -u
}

get_binary_path() {
    local binary="$1"
    local path
    path=$(which "$binary" 2>/dev/null || true)
    if [[ -z "$path" ]]; then
        echo "⚠️  Skipping $binary (not found)" >&2
        return 1
    fi
    echo "$path"
}

collect_deps() {
    local binary="$1"
    local libs
    libs=$(ldd "$binary" 2>/dev/null | awk '{print $3}' | grep '^/' || true)
    for lib in $libs; do
        deps_map["$lib"]+="$binary "
    done
}

human_size() {
    local size=$1
    local units=(B KiB MiB GiB)
    local unit_index=0
    while (( size > 1024 && unit_index < 3 )); do
        size=$(( size / 1024 ))
        ((unit_index++))
    done
    echo "${size}${units[$unit_index]}"
}

main() {
    local binaries=("$@")

    if [[ ${#binaries[@]} -eq 0 ]]; then
        echo -e "${YELLOW}No inputs specified, scanning .desktop files...${RESET}"
        mapfile -t binaries < <(get_binaries_from_desktop_files)
    fi

    echo -e "${GREEN}Analyzing ${#binaries[@]} applications...${RESET}"

    for app in "${binaries[@]}"; do
        local path
        path=$(get_binary_path "$app") || continue
        [[ -n "${app_seen[$path]+_}" ]] && continue
        app_seen["$path"]=1
        collect_deps "$path"
    done

    echo
    echo -e "${YELLOW}Shared Library Usage (by number of apps):${RESET}"
    echo "-------------------------------------------------------------"
    printf "%6s  %-10s  %s\n" "Count" "Size" "Library"
    echo "-------------------------------------------------------------"

    for lib in "${!deps_map[@]}"; do
        local unique_count
        unique_count=$(echo "${deps_map[$lib]}" | tr ' ' '\n' | sort -u | wc -l)
        local size="N/A"
        if [[ -f "$lib" ]]; then
            local bytes
            bytes=$(stat -c%s "$lib" 2>/dev/null || echo 0)
            size=$(numfmt --to=iec-i --suffix=B "$bytes" 2>/dev/null || human_size "$bytes")
        fi
        printf "%6d  %-10s  %s\n" "$unique_count" "$size" "$lib"
    done | sort -k1,1nr -k2,2h
}

main "$@"