最近學習UNIX環境網絡編程POSIX消息隊列的時候發現一個問題，在mq_open的時候總會報Permission denied的錯誤。

查看mq_overview后才得以解決。

mq_overview原文描述如下：

Mounting the message queue file system
?????? On Linux, message queues are created in a virtual file system.?? (Other
?????? implementations? may? also? provide such a feature, but the details are
?????? likely to differ.)? This file system can be mounted (by the? superuser)
?????? using the following commands:

?????????? # mkdir /dev/mqueue
?????????? # mount -t mqueue none /dev/mqueue

?????? The sticky bit is automatically enabled on the mount directory.

?????? After? the file system has been mounted, the message queues on the sys‐
?????? tem can be viewed and manipulated using the commands usually? used? for
?????? files (e.g., ls(1) and rm(1)).

創建MQ的代碼如下：

1 #include <unpipc.h> 2 3 int 4 main(int argc, char **argv) 5 { 6 int c, flags; 7 mqd_t mqd; 8 9 flags = O_RDWR | O_CREAT; 10 11 while ((c = Getopt(argc, argv, "e")) != -1) 12 { 13 switch (c) 14 { 15 case 'e': 16 flags |= O_EXCL; 17 break; 18 } 19 } 20 21 if (optind != argc - 1) 22 err_quit("usage: mqcreate [-e] <name>"); 23 24 mqd = Mq_open(argv[optind], flags, 0777, NULL); 25 Mq_close(mqd); 26 27 exit(0); 28 }

?

轉載于:https://www.cnblogs.com/zhiqli/p/3487638.html

總結

以上是生活随笔為你收集整理的【学习随手记】POSIX消息队列执行报Permission denied的问题。的全部內容，希望文章能夠幫你解決所遇到的問題。

如果覺得生活随笔網站內容還不錯，歡迎將生活随笔推薦給好友。