问题
I am trying to learn a bit of socket programming, I am also pretty new to c and having some trouble creating my server.
I am having trouble with pointers and the error I get when I try to run the code is
warning: passing 'int *' to parameter of type 'socklen_t *' (aka 'unsigned int *') converts between pointers to integer types with different sign [-Wpointer-sign]`
My server code is as follows, can anyone help with the error I am getting? Any other tips or comments are welcome as well
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
int main( int argc, char *argv[] )
{
int sockfd, newsockfd, portno, clilen;
char buffer[256];
struct sockaddr_in serv_addr, cli_addr;
int n;
/* First call to socket() function */
sockfd = socket(AF_INET, SOCK_STREAM, 0);
if (sockfd < 0)
{
perror("ERROR opening socket");
exit(1);
}
/* Initialize socket structure */
bzero((char *) &serv_addr, sizeof(serv_addr));
portno = 5001;
serv_addr.sin_family = AF_INET;
serv_addr.sin_addr.s_addr = INADDR_ANY;
serv_addr.sin_port = htons(portno);
/* Now bind the host address using bind() call.*/
if (bind(sockfd, (struct sockaddr *) &serv_addr, sizeof(serv_addr)) < 0)
{
perror("ERROR on binding");
exit(1);
}
/* Now start listening for the clients, here process will
* go in sleep mode and will wait for the incoming connection
*/
listen(sockfd,5);
clilen = sizeof(cli_addr);
/* Accept actual connection from the client */
newsockfd = accept(sockfd, (struct sockaddr *)&cli_addr, &clilen);
if (newsockfd < 0)
{
perror("ERROR on accept");
exit(1);
}
/* If connection is established then start communicating */
bzero(buffer,256);
n = read( newsockfd,buffer,255 );
if (n < 0)
{
perror("ERROR reading from socket");
exit(1);
}
printf("Here is the message: %s\n",buffer);
/* Write a response to the client */
n = write(newsockfd,"I got your message",18);
if (n < 0)
{
perror("ERROR writing to socket");
exit(1);
}
return 0;
}
回答1:
Well, Actually you could mention to the the exact place of the error so we could look faster.
Anyway the error is in the accept call where you passed an int * instead of socklen_t *. in
newsockfd = accept(sockfd, (struct sockaddr *)&cli_addr, &clilen);
So in this line:
int sockfd, newsockfd, portno, clilen;
change the declaration of clilen to
socklen_t clilen;
and it'll work.
来源:https://stackoverflow.com/questions/28550748/socket-programming-pointer-error