#pragma once #include int read_all(int fd, unsigned char *buf, size_t count); int read_some(int fd, unsigned char *buf, size_t *lenp); int write_all(int fd, unsigned const char *buf, size_t count); ssize_t read_file(char *buf, size_t len, const char *fmt, ...); int tcp_connect(const char *host, const char *port, char const **err);