emulate -L zsh

zmodload zsh/curses

test_fd0() {
    true <&0
}

local restore=0 FD

# Reattach to terminal
if [ ! -t 0 ]; then
    # Check if can reattach to terminal in any way
    if [[ ! -c /dev/tty && ! -t 2 ]]; then
        echo "No terminal available (no /dev/tty and no terminal at stderr)"
        return 1
    fi

    if test_fd0 2>/dev/null; then
        exec {FD}<&0
        restore=2
    else
        restore=1
    fi

    if [[ ! -c /dev/tty ]]; then
        exec <&2
    else
        exec </dev/tty
    fi
fi

# Run the command
"$@"

# Restore FD state
(( restore == 1 )) && exec <&-
(( restore == 2 )) && exec <&$FD && exec {FD}<&-

# vim: set filetype=zsh: