下面的示例代碼與服務器進程一樣工作。但是,當我加入一行C套接字引發錯誤代碼22,EINVAL - 無效參數
pid_t childpid;
下面
struct sockaddr_in servaddr, clientaddr;
失敗的錯誤代碼22,EINVAL線
connectfd = accept(listenfd, (struct sockaddr *) &clientaddr, &clientaddrlen);
- 無效的參數。我是C新手,我無法理解這個問題,你能幫我解答一下嗎?
謝謝。
#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <linux/in.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
extern int errno;
int main()
{
int clientaddrlen, listenfd, connectfd, bytes_rcvd, listen_queue_size=1;
short int port_no = 2000;
char buffer[1000];
struct sockaddr_in servaddr, clientaddr;
printf("Server running at port #%d\n", port_no);
// Create server socket.
if ((listenfd = socket(AF_INET, SOCK_STREAM, 0)) < 0)
{
fprintf(stderr, "Cannot create server socket! errno=%d \n", errno);
exit(-1);
}
printf("Server socket created\n");
// Bind (attach) this process to the server socket.
servaddr.sin_family = AF_INET;
servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
servaddr.sin_port = htons(port_no);
bind(listenfd, (struct sockaddr *) &servaddr, sizeof(servaddr));
printf("Server socket is bound to port #%d\n", port_no);
// Turn 'listenfd' to a listening socket. Listen queue size is 1.
listen(listenfd,listen_queue_size);
printf("Server listening with a queue of size %d. \n", listen_queue_size);
// Wait for connection(s) from client(s).
while (1)
{
connectfd = accept(listenfd, (struct sockaddr *) &clientaddr, &clientaddrlen);
printf("A client has connected\n");
if (recv(connectfd, buffer, sizeof(buffer), 0) > 0)
printf("Received message: %s\n", buffer);
close(connectfd);
printf("Server closed connection to client\n");
}
close(listenfd);
return 0;
}
咦?程序的行爲改變僅僅是因爲你添加了一個未使用的變量聲明?這似乎......不太可能,你粘貼了錯誤的行嗎? – unwind 2009-05-20 08:21:14
另外,您不要在此代碼中使用fork(),儘管標題... – 2009-05-20 08:24:02
實際上,此類行爲非常普遍。它改變了堆棧幀的大小,因此可能會暴露或隱藏緩衝區溢出等引起的問題。 – 2009-05-20 08:25:20