我的C ++程序无法打开命名管道

Question

I am trying to run C++ application that works perfectly on Mac OS under Ubuntu. The problem is due to failure in opening a named pipe.

I used mkfifo as follows:

  pipe_name_ = std::string("/tmp/myfifo");
  if (mkfifo(pipe_name_.c_str(), 0666) < 0) {
     error_print("Cannot create a named pipe\n");
     return -1;
  }

  if ((fd_ = open(pipe_name_.c_str(), O_RDONLY | O_CREAT, 0666)) < 0) {
     error_print("Cannot open file description named %s %s\n",
                 pipe_name_.c_str(), strerror(errno));
     return -1;
  }

However, this prints into screen the bellow message that is for open() :

Cannot open file description named /tmp/myfifo Invalid argument

My permissions status is as bellow:

$ls -la /tmp/myfifo
prw-r----- 1 hamidb nonconf 0 Jun 20 13:35 /tmp/myfifo
$umask
0027

I am wondering why it was working fine on Mac OS and not on Linux.

Answer 1

I believe that you have the wrong flags for open as you are not creating the file.

It should be

open(pipe_name_.c_str(), O_RDONLY)