#!/bin/sh
if [ $# != 0 ]; then
	cat << 'END' >&2
numenc is a command to run numen actions programmatically.
It writes its stdin to $NUMEN_PIPE else /tmp/numen-pipe,
and will exit immediately if the pipe is not being read.

Example:

    echo 'pen printf %s\\n "$NUMEN_TRANSCRIPT"' | numenc

END
	[ "$1" = -h ] || [ "$1" = --help ]; exit
fi

fifo_being_read(){
	[ -p "$1" ] && /bin/echo 1<>"$1" >"$1"
}

p="${NUMEN_PIPE:-/tmp/numen-pipe}"

if [ -p "$p" ] && ! [ -w "$p" ]; then
	echo "numenc: the pipe does not grant write permission: $p" >&2
	exit 1
fi
if ! fifo_being_read "$p"; then
	echo "numenc: no numen instance is reading the pipe: $p" >&2
	exit 1
fi
exec cat > "$p"