util.h

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <ctype.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <errno.h>
#include <sys/socket.h>
#include <netdb.h>
#include <netinet/in.h>
#include <arpa/inet.h>

typedef struct sockaddr SA;

#define RIO_BUFSIZE 8192
typedef struct {
    int rio_fd;                /* Descriptor for this internal buf */
    int rio_cnt;               /* Unread bytes in internal buf */
    char *rio_bufptr;          /* Next unread byte in internal buf */
    char rio_buf[RIO_BUFSIZE]; /* Internal buffer */
} rio_t;

#define	MAXLINE	 8192  /* Max text line length */
#define MAXBUF   8192  /* Max I/O buffer size */
#define LISTENQ  1024  /* Second argument to listen() */

extern char **environ; /* Defined by libc */

void unix_error(char *msg);
void gai_error(int code, char *msg);

pid_t Fork(void);
void Execve(const char *filename, char *const argv[], char *const envp[]);
pid_t Wait(int *status);

void *Mmap(void *addr, size_t len, int prot, int flags, int fd, off_t offset);
void Munmap(void *start, size_t length);

int Open(const char *pathname, int flags, mode_t mode);
void Close(int fd);
int Dup2(int fd1, int fd2);

int Socket(int domain, int type, int protocol);
void Setsockopt(int s, int level, int optname, const void *optval, int optlen);
void Bind(int sockfd, struct sockaddr *my_addr, int addrlen);
void Listen(int s, int backlog);
int Accept(int s, struct sockaddr *addr, socklen_t *addrlen);
void Connect(int sockfd, struct sockaddr *serv_addr, int addrlen);
void Getaddrinfo(const char *node, const char *service, 
                 const struct addrinfo *hints, struct addrinfo **res);
void Getnameinfo(const struct sockaddr *sa, socklen_t salen, char *host, size_t hostlen, char *serv, size_t servlen, int flags);
void Freeaddrinfo(struct addrinfo *res);

ssize_t rio_readn(int fd, void *usrbuf, size_t n);
ssize_t rio_writen(int fd, void *usrbuf, size_t n);
void rio_readinitb(rio_t *rp, int fd); 
ssize_t	rio_readnb(rio_t *rp, void *usrbuf, size_t n);
ssize_t	rio_readlineb(rio_t *rp, void *usrbuf, size_t maxlen);

ssize_t Rio_readn(int fd, void *usrbuf, size_t n);
void Rio_writen(int fd, void *usrbuf, size_t n);
void Rio_readinitb(rio_t *rp, int fd); 
ssize_t Rio_readnb(rio_t *rp, void *usrbuf, size_t n);
ssize_t Rio_readlineb(rio_t *rp, void *usrbuf, size_t maxlen);

int open_listenfd(char *port);
int Open_listenfd(char *port);