I was playing around with my shell (zsh v4.3.11) when I noticed something weird:

$ >/dev/null 2>/dev/null echo "Hello"

outputs nothing on the terminal, whereas

$ >/dev/null 2>/dev/null echo "Hello" | wc


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How does the redirection/pipe combination work here? How does wc see the Hello\n even though all output is redirected to /dev/null? And why do I see the output of wc when I've redirected everything to /dev/null?