判断命令是否在PATH环境变量中

public static bool IsInPath(string command)
{
    bool isInPath = false;
    // 判断PATH中是否存在 命令
    foreach (string test in (Environment.GetEnvironmentVariable("PATH") ?? "").Split(';'))
    {
        string path = test.Trim();
        if (!String.IsNullOrEmpty(path) && File.Exists(path = Path.Combine(path, command)))
        {
            isInPath = true;
            break; // 如果在PATH中找到 ，则退出循环
        }
    }

    return isInPath;
}

IsInPath("cmd.exe") // 返回 bool值

 

参考：http://csharptest.net/526/how-to-search-the-environments-path-for-an-exe-or-dll/index.html