flutter_server_box/lib/data/model/server/memory.dart

class Memory {
  int total;
  int used;
  int free;
  int cache;
  int avail;
  Memory(
      {required this.total,
      required this.used,
      required this.free,
      required this.cache,
      required this.avail});
}

final memItemReg = RegExp(r'([A-Z].+:)\s+([0-9]+) kB');

Memory parseMem(String raw) {
  final items = raw.split('\n').map((e) => memItemReg.firstMatch(e)).toList();

  final total = int.parse(
    items.firstWhere((e) => e?.group(1) == 'MemTotal:')?.group(2) ?? '1',
  );
  final free = int.parse(
    items.firstWhere((e) => e?.group(1) == 'MemFree:')?.group(2) ?? '0',
  );
  final cached = int.parse(
    items.firstWhere((e) => e?.group(1) == 'Cached:')?.group(2) ?? '0',
  );
  final available = int.parse(
    items.firstWhere((e) => e?.group(1) == 'MemAvailable:')?.group(2) ?? '0',
  );

  return Memory(
    total: total,
    used: total - available,
    free: free,
    cache: cached,
    avail: available,
  );
}

class Swap {
  final int total;
  final int used;
  final int free;
  final int cached;

  Swap({
    required this.total,
    required this.used,
    required this.free,
    required this.cached,
  });

  @override
  String toString() {
    return 'Swap{total: $total, used: $used, free: $free, cached: $cached}';
  }
}

Swap parseSwap(String raw) {
  final items = raw.split('\n').map((e) => memItemReg.firstMatch(e)).toList();

  final total = int.parse(
    items.firstWhere((e) => e?.group(1) == 'SwapTotal:')?.group(2) ?? '1',
  );
  final free = int.parse(
    items.firstWhere((e) => e?.group(1) == 'SwapFree:')?.group(2) ?? '0',
  );
  final cached = int.parse(
    items.firstWhere((e) => e?.group(1) == 'SwapCached:')?.group(2) ?? '0',
  );

  return Swap(
    total: total,
    used: total - free,
    free: free,
    cached: cached,
  );
}