这有点奇怪。我的代码没有输出我预期的内容。我在不同阶段添加了一些打印语句来查看哪里出错了。但仍然没有输出。
所以我在main函数开始处添加了一个printf语句,这让我感到非常困惑。
因此,我认为文件描述符可能出了问题。我把printf改成了fprintf。但仍然没有输出。使用fprintf打印到stderr确实可以工作!为什么会这样?
除了初始打印语句和返回语句之外,从main函数中删除所有内容会打印出结果。
代码
int main(void) {
fprintf(stdout, "STARTED!");
//Create an Internet domain socket
int sockfd = socket(AF_INET, SOCK_STREAM, 0);
//If this fails exit and print the error
if (sockfd == -1) {
printf("Error %d, cannot create socket", errno);
return 1;
}
printf("SOCKET CREATED!");
//Creates a socket address
struct sockaddr_in addr;
addr.sin_family = AF_INET;
addr.sin_port = htons(8080);
addr.sin_addr.s_addr = INADDR_ANY;
//Attempts to bind to the socket address, again prints to error if this fails.
if (bind(sockfd, (struct sockaddr *) &addr, sizeof(addr)) == -1)
{
printf("Error %d, cannot bind", errno);
return 1;
}
//Starts Listening for a client
if (listen(sockfd, 1) == -1)
{
printf("Error %d, cannot listen", errno);
return 1;
}
//If all is successful, server is operational
while(1)
{
//Creates a file descripter for the connection
int connfd;
//And a socket address for the client
struct sockaddr_in cliaddr;
socklen_t cliaddrlen = sizeof(cliaddr);
//If a connection attempt is made accepts it.
connfd = accept(sockfd, (struct sockaddr *) &cliaddr, &cliaddrlen);
if (connfd == -1) {
//If the connection fails print an error
printf("Error %d, cannot accept connection", errno);
continue;
}
//Otherwise process the request
else {
printf("CONNECTED!");
char end;
end = 1;
while (end)
{
process_request(connfd);
end = 0;
}
}
close(connfd);
}
close(sockfd);
return 0;
}
command 1>&2
将会有所帮助,以避免缓冲。 - Vincent Xue