编译C程序时出错

Question

I am trying to compile this C program but I am getting this message

warning: passing 'int *' to parameter of type 'socklen_t *'
(aka 'unsigned int *') converts between pointers to integer types with
different sign [-Wpointer-sign]
if ((new_s = accept(s, (struct sockaddr *) &sin, &addr_len)) < 0) {
                                                 ^~~~~~~~~

someone could help me?

#include<string.h>
#include<stdlib.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <fcntl.h> // for open
#include <unistd.h> // for close
#define SERVER_PORT 5432
#define MAX_PENDING 5
#define MAX_LINE 256

int main()
{
    struct sockaddr_in sin;
    char buf[MAX_LINE];
    int buf_len, addr_len;
    int s, new_s;
    /* build address data structure */
    bzero((char *)&sin, sizeof(sin));
    sin.sin_family = AF_INET;
    sin.sin_addr.s_addr = INADDR_ANY;
    sin.sin_port = htons(SERVER_PORT);
    /* setup passive open */
    if ((s = socket(PF_INET, SOCK_STREAM, 0)) < 0) {
        perror("simplex-talk: socket");
        exit(1);
    }
    if ((bind(s, (struct sockaddr *)&sin, sizeof(sin))) < 0) {
        perror("simplex-talk: bind");
        exit(1);
    }

    listen(s, MAX_PENDING);
    /* wait for connection, then receive and print text */
    while(1) {
        if ((new_s = accept(s, (struct sockaddr *) &sin, &addr_len)) < 0) {
            perror("simplex-talk: accept");
            exit(1);
        }
        while (buf_len == recv(new_s, buf, sizeof(buf), 0))
            fputs(buf, stdout);
        close(new_s);
    }
}

Answer 1

As the error message states, you're passing an int * argument to accept for the last argument when the function expects a socklen_t * for this argument.

So change the type of addr_len to socklen_t .