运行bls签名算法提示‘bls’ was not declared in this scope

Question

根据https://blog.csdn.net/qq_36291381/article/details/80573344

给出的例子来编写bls签名算法，

对下面那句话提示bls’ was not declared in this scope ，请问什么原因呀，要怎么改呀

Answer 1

命令行调用的话 需要用

system("bls < xxx");