socket 编程中的 Accept函数问题
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <sys/wait.h>
#include <unistd.h>
#include <arpa/inet.h>

#define MYPORT 3490 /* the port users will be connecting to */

#define BACKLOG 10 /* how many pending connections queue will hold */

main()
{
int sockfd, new_fd; /* listen on sock_fd, new connection on new_fd */
struct sockaddr_in my_addr; /* my address information */
struct sockaddr_in their_addr; /* connector 's address information */
int sin_size;

if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
perror( "socket ");
exit(1);
}

my_addr.sin_family = AF_INET; /* host byte order */
my_addr.sin_port = htons(MYPORT); /* short, network byte order */
my_addr.sin_addr.s_addr = INADDR_ANY; /* auto-fill with my IP */
bzero(&(my_addr.sin_zero), 8); /* zero the rest of the struct */

if (bind(sockfd, (struct sockaddr *)&my_addr, sizeof(struct sockaddr)) == -1) {
perror( "bind ");
exit(1);
}

if (listen(sockfd, BACKLOG) == -1) {

perror( "listen ");
exit(1);
}

while(1) { /* main accept() loop */
sin_size = sizeof(struct sockaddr_in);
if ((new_fd = accept(sockfd, (struct sockaddr *)&their_addr, &sin_size)) == -1) {
perror( "accept ");
continue;
}
printf( "server: got connection from %s\n ", \
inet_ntoa(their_addr.sin_addr));
if (!fork()) { /* this is the child process */
if (send(new_fd, "Hello, world!\n ", 14, 0) == -1)
perror( "send ");
close(new_fd);
exit(0);
}
close(new_fd); /* parent doesn 't need this */

while(waitpid(-1,NULL,WNOHANG) > 0); /* clean up child processes */
}
}

[cry@localhost C++自己练习]$ g++ -o server server.cpp
server.cpp:61:6: 警告：文件未以空白行结束
server.cpp: In function ‘int main()’:
server.cpp:45: 错误：从类型 ‘int*’ 到类型 ‘socklen_t*’ 的转换无效
server.cpp:45: 错误： 初始化实参 3，属于 ‘int accept(int, sockaddr*, socklen_t*)’
[cry@localhost C++自己练习]$

请高手指点为什么会报这个错。怎样改正。谢谢！

[解决办法]
呵呵，俺也遇到过，把int sin_size;改为socklen_t sin_size就可以了。
原因在编译器的输出里已经说的很明白了，accept的最后一个参数是需要socklen_t*的类型
希望能够对你有所帮助