TimerApp/PortableMode.cs

using System;

namespace TimerApp
{
    internal static class PortableMode
    {
        private const string PortableEnvVarName = "TIMERAPP_PORTABLE";

        public static bool IsPortable
        {
            get
            {
                try
                {
                    string? env = Environment.GetEnvironmentVariable(PortableEnvVarName);
                    if (!string.IsNullOrWhiteSpace(env))
                    {
                        if (string.Equals(env, "0", StringComparison.OrdinalIgnoreCase) ||
                            string.Equals(env, "false", StringComparison.OrdinalIgnoreCase) ||
                            string.Equals(env, "no", StringComparison.OrdinalIgnoreCase) ||
                            string.Equals(env, "off", StringComparison.OrdinalIgnoreCase) ||
                            string.Equals(env, "disable", StringComparison.OrdinalIgnoreCase))
                        {
                            return false;
                        }

                        if (string.Equals(env, "1", StringComparison.OrdinalIgnoreCase) ||
                            string.Equals(env, "true", StringComparison.OrdinalIgnoreCase) ||
                            string.Equals(env, "yes", StringComparison.OrdinalIgnoreCase) ||
                            string.Equals(env, "on", StringComparison.OrdinalIgnoreCase) ||
                            string.Equals(env, "enable", StringComparison.OrdinalIgnoreCase))
                        {
                            return true;
                        }
                    }

                    return true;
                }
                catch
                {
                    return true;
                }
            }
        }
    }
}