Socket client server program, client can create a record and Record is a string of fixed length, known to both client and server.
Here are my code server is
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <errno.h>
#include <unistd.h>
#define BufferLength 100
#define SERVPORT 3111
#pragma pack(1)
struct emprec
{
int empid;
char *name;
};
#pragma pack(0)
typedef struct emprec emp;
int main()
{
int sd, sd2, rc, length = sizeof(int);
int totalcnt = 0, on = 1;
char temp;
char buffer[BufferLength];
struct sockaddr_in serveraddr;
struct sockaddr_in their_addr;
fd_set read_fd;
struct timeval timeout;
timeout.tv_sec = 15;
timeout.tv_usec = 0;
if((sd = socket(AF_INET, SOCK_STREAM, 0)) < 0)
{
perror("Server-socket() error");
exit (-1);
}
else
printf("Server-socket() is OK\n");
if((rc = setsockopt(sd, SOL_SOCKET, SO_REUSEADDR, (char *)&on, sizeof(on))) < 0)
{
perror("Server-setsockopt() error");
close(sd);
exit (-1);
}
else
printf("Server-setsockopt() is OK\n");
memset(&serveraddr, 0x00, sizeof(struct sockaddr_in));
serveraddr.sin_family = AF_INET;
serveraddr.sin_port = htons(SERVPORT);
serveraddr.sin_addr.s_addr = htonl(INADDR_ANY);
if((rc = bind(sd, (struct sockaddr *)&serveraddr, sizeof(serveraddr))) < 0)
{
perror("Server-bind() error");
close(sd);
exit(-1);
}
else
printf("Server-bind() is OK\n");
if((rc = listen(sd, 10)) < 0)
{
perror("Server-listen() error");
close(sd);
exit (-1);
}
else
printf("Server-Ready for client connection...\n");
int sin_size = sizeof(struct sockaddr_in);
if((sd2 = accept(sd, (struct sockaddr *)&their_addr, &sin_size)) < 0)
{
perror("Server-accept() error");
close(sd);
exit (-1);
}
else
printf("Server-accept() is OK\n");
printf("Server-new socket, sd2 is OK...\n");
FD_ZERO(&read_fd);
FD_SET(sd2, &read_fd);
rc = select(sd2+1, &read_fd, NULL, NULL, &timeout);
if((rc == 1) && (FD_ISSET(sd2, &read_fd)))
{
totalcnt = 0;
while(totalcnt < BufferLength)
{
rc = read(sd2, &buffer[totalcnt], (BufferLength - totalcnt));
if(rc < 0)
{
perror("Server-read() error");
close(sd);
close(sd2);
exit (-1);
}
else if (rc == 0)
{
printf("Client program has issued a close()\n");
close(sd);
close(sd2);
exit(-1);
}
else
{
totalcnt += rc;
printf("Server-read() is OK\n");
}
}
}
else if (rc < 0)
{
perror("Server-select() error");
close(sd);
close(sd2);
exit(-1);
}
else
{
printf("Server-select() timed out.\n");
close(sd);
close(sd2);
exit(-1);
}
printf("Received data from the f***ing client: %s\n", buffer);
printf("Server-Echoing back to client...\n");
rc = write(sd2, buffer, totalcnt);
if(rc != totalcnt)
{
perror("Server-write() error");
rc = getsockopt(sd2, SOL_SOCKET, SO_ERROR, &temp, &length);
if(rc == 0)
{
errno = temp;
perror("SO_ERROR was: ");
}
else
printf("Server-write() is OK\n");
close(sd);
close(sd2);
exit(-1);
}
close(sd2);
close(sd);
exit(0);
return 0;
}
and client is
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <unistd.h>
#include <errno.h>
#define BufferLength 100
#define SERVER "The_server_name_or_IP"
#define SERVPORT 3111
FILE *fd = NULL;
#pragma pack(1)
struct emprec
{
int empid;
char *name;
};
#pragma pack(0)
typedef struct emprec emp;
char data1[100];
int main(int argc, char *argv[])
{
int sd, rc, length = sizeof(int);
struct sockaddr_in serveraddr;
char buffer[BufferLength];
char server[255];
char temp;
int totalcnt = 0;
struct hostent *hostp;
char data[100] = "This is a test string from client lol!!! ";
if((sd = socket(AF_INET, SOCK_STREAM, 0)) < 0)
{
perror("Client-socket() error");
exit(-1);
}
else
printf("Client-socket() OK\n");
if(argc > 1)
{
strcpy(server, argv[1]);
printf("Connecting to the f***ing %s, port %d ...\n", server, SERVPORT);
}
else
strcpy(server, SERVER);
memset(&serveraddr, 0x00, sizeof(struct sockaddr_in));
serveraddr.sin_family = AF_INET;
serveraddr.sin_port = htons(SERVPORT);
if((serveraddr.sin_addr.s_addr = inet_addr(server)) == (unsigned long)INADDR_NONE)
{
hostp = gethostbyname(server);
if(hostp == (struct hostent *)NULL)
{
printf("HOST NOT FOUND --> ");
printf("h_errno = %d\n",h_errno);
printf("---This is a client program---\n");
printf("Command usage: %s <server name or IP>\n", argv[0]);
close(sd);
exit(-1);
}
memcpy(&serveraddr.sin_addr, hostp->h_addr, sizeof(serveraddr.sin_addr));
}
if((rc = connect(sd, (struct sockaddr *)&serveraddr, sizeof(serveraddr))) < 0)
{
perror("Client-connect() error");
close(sd);
exit(-1);
}
else
printf("Connection established...\n");
printf("Sending some string to the f***ing %s...\n", server);
emp temp1;
temp1.name = (char *)malloc(200 * sizeof(char)); temp1.empid=3;
temp1.name = "tar";
rc =write(sd,&temp1,sizeof(temp1));
if(rc < 0)
{
perror("Client-write() error");
rc = getsockopt(sd, SOL_SOCKET, SO_ERROR, &temp, &length);
if(rc == 0)
{
errno = temp;
perror("SO_ERROR was");
}
close(sd);
exit(-1);
}
else
{
printf("Client-write() is OK\n");
printf("String successfully sent lol!\n");
printf("Waiting the %s to echo back...\n", server);
}
totalcnt = 0;
while(totalcnt < BufferLength)
{
rc = read(sd, &buffer[totalcnt], BufferLength-totalcnt);
if(rc < 0)
{
perror("Client-read() error");
close(sd);
exit(-1);
}
else if (rc == 0)
{
printf("Server program has issued a close()\n");
close(sd);
exit(-1);
}
else
totalcnt += rc;
}
printf("Client-read() is OK\n");
printf("Echoed data from the f***ing server: %s\n", buffer);
close(sd);
exit(0);
return 0;
}