Can named pipes be configured in a way so that these are durable?
Depending on your definition of durable, yes. mkfifo creates the fifo or named pipe, and it remains there until you delete it.
I read about "pinning" to pipe by the writer, but I fail to get that to work
Not sure what you mean by that. However, if you are not in control of the writer, this would not be a solution.
Can I prevent a pipe from getting closed once the reader exits?
You can use tail -f on the fifo, instead of a cat. Or even tail -n +1 -f fifo_name | command
Some additional information: whan cat encounters the end-of-file, it exits. So, if you do
$ mkfifo fifootje
$ cat fifootje
and in another terminal
echo hop > fifootje
you get the hop from the cat, and cat exits. If your writer then does
$ echo plop > fifootje
it hangs until a new cat fifootje is issued.
tail -f ("follow" or "forever") just waits until some lines are added and it does not exit until killed. So,
$ tail -f fifootje
hop
plop
and more text
entered via cat
^C
and in the writer terminal:
$ echo hop > fifootje
ljm@verlaine[/tmp]$ echo plop > fifootje
ljm@verlaine[/tmp]$ cat > fifootje
and more text
entered via cat
^D
Alternatively, you could:
while : ; do
cat fifootje
done
Are there alternatives that behave like a pipe?
Yes, sockets.