编译器警告“签名不同”[关闭]答案

【问题标题】：compiler warnings "differ in signedness" [closed]编译器警告“签名不同”[关闭]
【发布时间】：2014-08-08 08:57:06
【问题描述】：

编译器警告“签名不同”

comm.c: In function ‘new_descriptor’:
comm.c:1017: warning: pointer targets in passing argument 3 of ‘accept’ differ in signedness
comm.c: In function ‘get_ident’:
comm.c:4043: warning: pointer targets in passing argument 3 of ‘getsockname’ differ in signedness
comm.c:4044: warning: pointer targets in passing argument 3 of ‘getpeername’ differ in signedness

void new_descriptor(int control)
{
static DESCRIPTOR_DATA d_zero;
DESCRIPTOR_DATA *dnew;
struct sockaddr_in sock;
BAN_DATA *pban;
char buf[MAX_STRING_LENGTH];
int desc;
int size;
int addr;
int hostcount;
DESCRIPTOR_DATA *d;

NORESOLVE_DATA *pnoresolve;
bool doresolve;

size = sizeof(sock);
if ((desc = accept(control, (struct sockaddr *) &sock, &size)) < 0) {
    perror("New_descriptor: accept");
    return;
}

和

char *get_ident(int desc, u_long ip)
 {
struct sockaddr_in us;
struct sockaddr_in them;
static char uid[MAX_STRING_LENGTH];
char buf[MAX_STRING_LENGTH];
int id;
int size;

strcpy(uid, "(unknown)");

if ((id = start_socket(ip, IDENT_PORT)) < 0)
    return uid;

size = sizeof(us);

if (getsockname(desc, (struct sockaddr *) &us, &size)
    || getpeername(desc, (struct sockaddr *) &them, &size)) {
    CLOSE(id);
    return uid;
}

sprintf(buf, "%u, %u\n", ntohs(them.sin_port), ntohs(us.sin_port));

WRITE(id, buf, strlen(buf) + 1);

memset(buf, '\0', sizeof(buf));

READ(id, buf, sizeof(buf) - 1);

if (sscanf(buf, "%*d , %*d : USERID : %*s : %[^\r\n]s", uid) != 1)
    strcpy(uid, "(unknown)");

if (!strcmp(uid, "0"))
    strcpy(uid, "root");

CLOSE(id);
return uid;
}
#endif

【问题讨论】：

问这种问题的人的冷漠总是让我感到惊讶。
看来参数应该是一个无符号的`socklen_t*`。

标签： c

【解决方案1】：

您正在使用int size;，您不应将int 数据类型用于accept 的第三个参数。

accept 的语法是-

int accept(int sockfd, struct sockaddr *addr, socklen_t *addrlen); // 注意第三个参数

所以你应该使用socklen_t 数据类型。尝试将size 声明为socklen_t 变量并尝试-

socklen_t size; //like this

【讨论】：