Re: [PATCH] t5570: forward git-daemon messages in a different way

Am 4/19/2012 8:03, schrieb Jeff King:

mkfifo fd
yes >fd &
pid=$!
{
        read line
        echo $line
        cat <fd &
} <fd
sleep 1
kill $pid
wait $pid
rm -f fd

...

Hmm. Yeah, if you strace the cat, it gets an immediate EOF. And even
weirder, I notice this in the strace output:

  clone(...)
  close(0)                                = 0
  open("/dev/null", O_RDONLY)             = 0
  ...
  execve("/bin/cat", ["cat"], [/* 50 vars */]) = 0

What? The shell is literally redirecting the cat process's stdin from
/dev/null. I'm totally confused.

You don't have to be; it's mandated by POSIX:

http://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_09_03_02

-- Hannes