#include #include #include #include #include #include #include #include #include static bool stop = false;static void handle_term(int sig){ stop = true; }int main(int argc, char *argv[]){ signal(SIGTERM, handle_term); if (argc <= 3) { printf("usage: %s ip_address port_number backlog\n", basename(argv[0])); return 1; } const char *ip = argv[1]; int port = atoi(argv[2]); int backlog = atoi(argv[3]); int sock = socket(PF_INET, SOCK_STREAM, 0); assert(sock >= 0); struct sockaddr_in address; bzero(&address, sizeof(address)); address.sin_family = AF_INET; inet_pton(AF_INET, ip, &address.sin_addr); address.sin_port = htons(port); int ret = bind(sock, (struct sockaddr*)&address, sizeof(address)); assert(ret != -1); ret = listen(sock, backlog); assert(ret != -1); while (!stop) { sleep(1); } close(sock); return 0; }

直接用g++可以编译成功，但是我用env查看环境变量发现没有包含/usr/include这个路径呀？一些头文件不是在这个文件夹下的吗？请问为什么可以编译成功呢，怎么找到这些头文件的呢？