Unix系統編程：文件打開錯誤

Question

我想打開一個我剛剛打開的命令之前創建的文件。但它掛在open()命令行。你有什麼主意嗎？

if(mkfifo("test", S_IRWXU | S_IRWXG | S_IRWXO)) 
{ 
    printf("File creation error.\n"); 
    return 0; 
} 

// Hangs below 
while (((test_fd = open("test", O_RDONLY)) == -1) && (errno == EINTR)); 

Answer 1

從mkfifo的手冊頁：

Opening a FIFO for reading normally blocks until some other process opens the same FIFO for writing, and vice versa. 
See fifo(7) for nonblocking handling of FIFO special files.