Read noonnamed pipe in terminal

Question

Hellow. I have very simple C program. I create pipe in program (standard, non-named). Can I read pipe of existing process in terminal (stream with > or cat?). I try it but my command do nothing. Im know tkat i can create named pipe who is very easy for external I/O. I have number of pipe for /proc/number/fd Why I need it? Just from debug (but not only, i know that gdb can look pipe). When i fork process, children inherits pts (terminal) and std io/out. Change pts is possible but it is bad way. So I will open next terminal and stream existing process pipie in it. It is possible (and decent, dizzy way dont interesting me) or I must used named pipe?

Answer 1

Can I read pipe of existing process in terminal (stream with > or cat?)

Yes, you can. Example rnpit.c:

#include <string.h>
main()
{
    int pipefd[2];
    pipe(pipefd);
    write(pipefd[1], "pipe", strlen("pipe"));
    sleep(99);  // give us time to read the pipe
}

---

>rnpit&
[1] 1077
>ll /proc/${!}/fd
total 0
lrwx------ 1 armali ARNGO_res4 64 Apr  4 09:22 0 -> /dev/pts/5
lrwx------ 1 armali ARNGO_res4 64 Apr  4 09:22 1 -> /dev/pts/5
lrwx------ 1 armali ARNGO_res4 64 Apr  4 09:22 2 -> /dev/pts/5
lr-x------ 1 armali ARNGO_res4 64 Apr  4 09:22 3 -> pipe:[399466140]
l-wx------ 1 armali ARNGO_res4 64 Apr  4 09:22 4 -> pipe:[399466140]
>cat /proc/${!}/fd/3
pipe