c - C中架构x86_64 termcap.h的未定义符号

Question

我有这个代码：

#include <stdio.h>
#include <termcap.h>
#include <stdlib.h>

int main() {
    char *termtype = getenv("TERM");
    int li = tgetnum("li");
    printf("%d", li);
    return 0;
}

我无法编译它，因为我得到了

    Undefined symbols for architecture x86_64:
      "_tgetnum", referenced from:
          _main in main-11560e.o
    ld: symbol(s) not found for architecture x86_64
    clang: error: linker command failed with exit code 1 (use -v to see invocation)

为什么会这样？
macOS 卡塔利娜