How to write to the client twice? - c

Question

I'm trying to send to the client the bits he has to read, then he has to read them. But for some reason he doesn't read the message, he only reads the bites,msgLength.I get the message form the server[server]The message was sent succefully.And the client is able to read only the msgLength, the msg is empty.
client:
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <errno.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <netdb.h>
#include <string.h>
#include <fcntl.h>
extern int errno;
int port;
int main(int argc, char *argv[])
{
int sd;
struct sockaddr_in server;
char msg[200];
int fd;
char msgLength[200];
if (argc != 3)
{
printf("Sintax: %s <adress_server> <port>\n", argv[0]);
return -1;
}
port = atoi(argv[2]);
if ((sd = socket(AF_INET, SOCK_STREAM, 0)) == -1)
{
perror("Error on socket().\n");
return errno;
}
server.sin_family = AF_INET;
server.sin_addr.s_addr = inet_addr(argv[1]);
server.sin_port = htons(port);
if (connect(sd, (struct sockaddr *)&server, sizeof(struct sockaddr)) == -1)
{
perror("[client]Erorr on connect().\n");
return errno;
}
if (recv(sd, msgLength, 2,0) < 0)
{
perror("[client]Erorr on recv() from the server.\n");
return errno;
}
bzero(msg,100);
if (recv(sd, msg, 22,0)<0){
perror("[client]Erorr on the second recv() from the server.\n");
return errno;
}
printf("msgLength: %s\n",msgLength);
printf("[client]The message recived is: %s\n", msg);
close(sd);
}
server:
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <errno.h>
#include <unistd.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <fcntl.h>
#include <sys/wait.h>
#define PORT 2024
extern int errno;
int main()
{
struct sockaddr_in server; r
struct sockaddr_in from;
char msg[100];
char msgrasp[100] = " ";
int sd;
pid_t pid;
if ((sd = socket(AF_INET, SOCK_STREAM, 0)) == -1)
{
perror("[server]Erorr on the socket().\n");
return errno;
}
bzero(&server, sizeof(server));
bzero(&from, sizeof(from));
server.sin_family = AF_INET;
server.sin_addr.s_addr = htonl(INADDR_ANY);
server.sin_port = htons(PORT);
int optval = 1;
setsockopt(sd, SOL_SOCKET, SO_REUSEADDR, &optval, sizeof(optval));
setsockopt(sd, SOL_SOCKET, SO_REUSEPORT, &optval, sizeof(optval));
*/
if (bind(sd, (struct sockaddr *)&server, sizeof(struct sockaddr)) == -1)
{
perror("[server]Erorr on the bind().\n");
return errno;
}
if (listen(sd, 5) == -1)
{
perror("[server]Erorr on listen().\n");
return errno;
}
while (1)
{
int client;
int length = sizeof(from);
printf("[server]We wait on the port %d...\n", PORT);
fflush(stdout);
client = accept(sd, (struct sockaddr *)&from, &length);
if (client < 0)
{
perror("[server]Erorr on accept().\n");
continue;
}
switch (pid = fork())
{
case -1:
perror("fork");
exit(1);
break;
case 0:
close(sd);
bzero(msg, 100);
printf("[server]Sending the text...\n");
fflush(stdout);
int fd1 = open("ToSend.txt", O_RDONLY);
char msgLength[100];
read(fd1, msgrasp, 100);
sprintf(msgLength,"%ld",strlen(msgrasp)+1);
printf("msgLength: %d\n",atoi(msgLength));
if ((send(client,msgLength,sizeof(msgLength),0) && send(client, msgrasp, atoi(msgLength),0)) <= 0)
{
perror("[server]Erorr on send() to the client.\n");
continue;
}
else
printf("[server]The message was sent succefully.\n");
exit(2);
default:
wait(NULL);
close(client);
break;
}
}
}

Answer 1

I solved it. The problem was that the server was sending sizeof(msgLength) witch is 100, and the client was reading just 2. If i replace sizeof(msgLength) with strlen(msgLength)+1 it works just fine. Thank you all for your time.