/*
Lab. Calcolo II - Esempio di codice
<![CDATA[
Example code: socket listen and receive demonstration (uses shelper calls)
(20000818 prelz@mi.infn.it)
*/
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <sys/socket.h>
int
main (int argc, char *argv[])
{
char prov_host[80];
char *message = NULL;
int allocated_size = 0;
char buffer[80];
int listen_port = 1313;
int read_chars;
int recv_chars;
int s;
printf("Listening for messages...\n");
s = SHLP_listen_and_connect(listen_port, 0, prov_host, sizeof(prov_host));
if (s<0)
{
fprintf(stderr,"Couldn't accept a connection on port %d\n",
listen_port);
exit(1);
}
/* In general we cannot assume we know the size of the message */
/* we are waiting for */
read_chars = 0;
while ((recv_chars = recv(s,buffer,sizeof(buffer),0)) > 0)
{
if ((read_chars + recv_chars) > allocated_size)
{
/* We increase the allocated size by a "buffer"-sized chunk */
allocated_size += sizeof(buffer)+1;
message = (char *)realloc(message,allocated_size);
if (message == NULL)
{
allocated_size = 0;
perror("Error allocating buffer for incoming message");
close(s);
exit(1);
}
}
memcpy(&message[read_chars],buffer,recv_chars);
read_chars += recv_chars;
/* Make sure we have a terminating NULL */
message[read_chars] = '\000';
}
if (recv_chars < 0)
{
fprintf(stderr,"Error receiving message.");
close(s);
exit(1);
}
printf("Received a message from <%s>:\n", prov_host);
printf("%s\n", message);
close(s);
exit(0);
}
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