How to change the fd associated with the stdin file descriptor?

问题

I want to associate pipe's write fd to the stdout.

int pfds[2];
char buf[30];

if (pipe(pfds) == -1) {
    perror("pipe");
    exit(1);
}

I want to associate pfd[1] to the stdout of the process. 

I understand, we can use freopen to redirect stdout to the file. I was hoping to get something similar to this.

回答1:

dup2(2) is probably the easiest way:

dup2(pfds[1], STDOUT_FILENO);

来源：https://stackoverflow.com/questions/18497401/how-to-change-the-fd-associated-with-the-stdin-file-descriptor