Hello i have a problem with this program, the client should send a string of two lines from standard input to the server and the server should receive the string of two lines and send back to the client.
Code:
/
//client
#include "basic.h"
void client_echo(FILE *fp, int sockfd, int nlines);
char *fngets(char *s, int maxline, FILE *fp, int nlines);
int main(int argc, char **argv) {
int sockfd, n;
struct sockaddr_in servaddr;
if (argc != 4)
{ printf("usage: echocli <IPaddress> <PORT> <number of lines>\n"); exit(1); }
if ( (sockfd = socket(AF_INET, SOCK_STREAM, 0)) < 0)
{ printf("socket error\n"); exit(1); }
bzero(&servaddr, sizeof(servaddr));
servaddr.sin_family = AF_INET;
servaddr.sin_port = htons(atoi(argv[2])); /* echo server port */
if (inet_pton(AF_INET, argv[1], &servaddr.sin_addr) <= 0)
{ printf("inet_pton error for %s", argv[1]); exit(1);}
if (connect(sockfd, (struct sockaddr *) &servaddr, sizeof(servaddr)) < 0)
{ printf("connect error\n"); exit(1);}
client_echo(stdin, sockfd, atoi(argv[3]));
exit(0);
}
void client_echo(FILE *fp, int sockfd, int nlines) {
char sendline[MAXLINE], recvline[MAXLINE];
int n;
int i = 0;
while (fngets(sendline, MAXLINE, fp, nlines) != NULL) {
reti_writen(sockfd, sendline, strlen(sendline));
while ((n = read(sockfd, recvline, MAXLINE)) > 0) {
write(1, recvline, n);
}
printf("fine client\n");
}
}
char *fngets(char *s, int maxline, FILE *fp, int nlines)
{
char tmp[MAXLINE];
bzero(s, sizeof(s));
while (nlines-- > 0 && fgets(tmp, maxline, fp) != NULL)
strcat(s, tmp);
if (nlines > 0)
s = NULL;
return s;
}
Code:
//server
#include "basic.h"
void server_echo(int sockfd);
int main(int argc, char **argv) {
pid_t childpid;
int listenfd, connfd;
struct sockaddr_in servaddr, cliaddr;
socklen_t cliaddr_len;
if( argc != 2){
printf("Usage: echosrv <PORT> \n"); exit(1);
}
if( (listenfd = socket(AF_INET, SOCK_STREAM, 0)) < 0)
{ printf("socket error\n"); exit(1); }
bzero(&servaddr, sizeof(servaddr));
servaddr.sin_family = AF_INET;
servaddr.sin_addr.s_addr = htonl(INADDR_ANY); /* wildcard address */
servaddr.sin_port = htons(atoi(argv[1])); /* echo server */
if( (bind(listenfd, (struct sockaddr *) &servaddr, sizeof(servaddr))) < 0)
{ printf("bind error\n"); exit(1); }
if( listen(listenfd, BACKLOG) < 0 )
{ printf("listen error\n"); exit(1);}
for ( ; ; ) {
cliaddr_len = sizeof(cliaddr);
if( (connfd = accept(listenfd, (struct sockaddr *) &cliaddr, &cliaddr_len)) < 0)
{ printf("accept error\n"); exit(1); }
if( (childpid = fork()) == 0 ) {
close(listenfd);
server_echo(connfd);
exit(0);
}
close(connfd);
}
}
void server_echo(int sockfd) {
ssize_t n;
char line[MAXLINE];
while ((n = read(sockfd, line, MAXLINE)) > 0)
write(sockfd, line, n);
if (n == 0)
return;
else if (n < 0){
fprintf(stderr, "server_echo: read error\n");
return;
}
}