C Socket

Bacchus

Hi,
Does anyone know where to get a simple socket server in C that will recieve and display messages sent to it from a client.
I need it to test a J2ME client application I made.
I'v searched the web, but I can ones which are used as chat servers or for sending images etc.
Thanks,
Bacchus

DaemÈn

heres a simple one i was working with a while back ... u might have to make a few changes ... i havent time to compile it at d mo but as far as i can remember its working.....

/****************SERVER********************************/
/*Server*/
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>

#define LOCAL_SERVER_PORT 1500
#define MAX_MSG 100

int main(int argc, char *argv[])
{

int soc, rc, n, cliLen;
struct sockaddr_in cliAddr, servAddr;
char msg[MAX_MSG];

/* create socket */
soc=socket(AF_INET, SOCK_DGRAM, 0);
if(soc<0)
{
perror("Socket Failure\n");
exit(1);
}

/* bind local server port */
servAddr.sin_family = AF_INET;
servAddr.sin_addr.s_addr = htonl(INADDR_ANY);
servAddr.sin_port = htons(LOCAL_SERVER_PORT);

rc = bind (soc, (struct sockaddr *) &servAddr,sizeof(servAddr));

if(rc<0)
{
printf("Cannot bind port number %d", LOCAL_SERVER_PORT);
exit(1);
}
/**************************************************************************/

printf("%s: waiting for data on port UDP %u\n", argv[0],LOCAL_SERVER_PORT);

/* server loop */
while(1)
{
memset(msg,0x0,MAX_MSG); /* init buffer */


cliLen = sizeof(cliAddr); /* receive data */
n = recvfrom(soc, msg, MAX_MSG, 0, (struct sockaddr *) &cliAddr, &cliLen);

if(n<0)
{
perror("\ncannot receive data");
continue;
}

/* print received message */
printf("%s: from %s:UDP%u : %s \n",
argv[0],inet_ntoa(cliAddr.sin_addr),
ntohs(cliAddr.sin_port),msg);

}/* end of server loop */

/****************************************************************************/

return 0;

}


/****************SERVER********************************/





/****************CLIENT********************************/

/*Client*/
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <sys/time.h>

#define REMOTE_SERVER_PORT 1500
#define MAX_MSG 100


int main(int argc, char *argv[])
{

int soc, rc, i;
struct sockaddr_in cliAddr, remoteServAddr;
struct hostent *h;

/* check command line args */
if(argc<3)
{
printf("usage : %s <server> <data1> ... <dataN> \n", argv[0]);
exit(1);
}

/* get server IP address (no check if input is IP address or DNS name */
h = gethostbyname(argv[1]);
if(h==NULL)
{
printf("%s: unknown host '%s' \n", argv[0], argv[1]);
exit(1);
}
/************************************************************************/
printf("%s: sending data to '%s' (IP : %s) \n", argv[0], h->h_name,
inet_ntoa(*(struct in_addr *)h->h_addr_list[0]));

remoteServAddr.sin_family = h->h_addrtype;
memcpy((char *) &remoteServAddr.sin_addr.s_addr,
h->h_addr_list[0], h->h_length);
remoteServAddr.sin_port = htons(REMOTE_SERVER_PORT);

/* socket creation */
soc = socket(AF_INET,SOCK_DGRAM,0);
if(soc<0)
{
printf("%s: cannot open socket \n",argv[0]);
exit(1);
}

/* bind any port */
cliAddr.sin_family = AF_INET;
cliAddr.sin_addr.s_addr = htonl(INADDR_ANY);
cliAddr.sin_port = htons(0);

rc = bind(soc, (struct sockaddr *) &cliAddr, sizeof(cliAddr));
if(rc<0)
{
printf("%s: cannot bind port\n", argv[0]);
exit(1);
}


/* send data */
for(i=2;i<argc;i++)
{
rc = sendto(soc, argv, strlen(argv)+1, 0,
(struct sockaddr *) &remoteServAddr,
sizeof(remoteServAddr));

if(rc<0)
{
printf("%s: cannot send data %d \n",argv[0],i-1);
close(soc);
exit(1);
}

}

return 1;

}


/****************CLIENT********************************/

Bacchus

Thanks DaemÈn, got it going.