Homework & Coursework Questions

#include	"myfile.h"

int
main(int argc, char **argv)
{
int	 sockfd, n;
char	 recvline[MAXLINE + 1];
struct sockaddr_in	servaddr;

if (argc != 2) {
perror("usage: a.out <IPaddress>");
exit (1);
}


if ( (sockfd = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
perror("socket error");
exit(1);
}

bzero(&servaddr, sizeof(servaddr));
servaddr.sin_family = AF_INET;
servaddr.sin_port = htons(SERV_PORT);	/* daytime server */
if (inet_pton(AF_INET, argv[1], &servaddr.sin_addr) <= 0) {
printf("inet_pton error for %s", argv[1]);
exit(0);
}

if (connect(sockfd, (struct sockaddr *) &servaddr, sizeof(servaddr)) < 0) {
perror("connect error");
exit(1);
}

while ( (n = read(sockfd, recvline, MAXLINE)) > 0) {
recvline[n] = 0;	/* null terminate */
if (fputs(recvline, stdout) == EOF) {
perror("fputs error");
exit(1);
}
}
if (n < 0) {
perror("read error");
}

exit(0);
}

Server code is


Code:
#include	"myfile.h"
#include	<time.h>

int
main(int argc, char **argv)
{
int	 listenfd, connfd;
struct sockaddr_in	servaddr;
char	 buff[MAXLINE];
time_t	 ticks;

listenfd = socket(AF_INET, SOCK_STREAM, 0);
if (listenfd < 0)
exit(0);

bzero(&servaddr, sizeof(servaddr));
servaddr.sin_family = AF_INET;
servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
servaddr.sin_port = htons(SERV_PORT);	/* daytime server */

if (bind(listenfd, (struct sockaddr *) &servaddr, sizeof(servaddr)) < 0)
exit(0);

if( listen(listenfd, LISTENQ) <0)
exit(0);

for ( ; ; ) {
connfd = accept(listenfd, (struct sockaddr *) NULL, NULL);
if (connfd<0) {
perror("connection failure");
continue;
}

ticks = time(NULL);
snprintf(buff, sizeof(buff), "%.24s\r\n", ctime(&ticks));
if( write(connfd, buff, strlen(buff)) < 0) {
perror("error in writing");
}

close(connfd);
}
}