From 2314a4aa5dd648b2d8ea314f41e76ce6ada13cc9 Mon Sep 17 00:00:00 2001
From: Rusty Russell <rusty@rustcorp.com.au>
Date: Fri, 17 Aug 2018 14:26:56 +0930
Subject: [PATCH] contrib/short_channel_id-to-txid.sh: simple mapping util.

I use this to look up on smartbit.com.au to see if a channel is spent,
for example.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
---
 contrib/short_channel_id-to-txid.sh | 15 +++++++++++++++
 1 file changed, 15 insertions(+)
 create mode 100755 contrib/short_channel_id-to-txid.sh

diff --git a/contrib/short_channel_id-to-txid.sh b/contrib/short_channel_id-to-txid.sh
new file mode 100755
index 000000000..1a4af3f4d
--- /dev/null
+++ b/contrib/short_channel_id-to-txid.sh
@@ -0,0 +1,15 @@
+#! /bin/sh
+
+set -e
+
+if [ "$#" != 1 ]; then
+    echo Usage: "$0" "short:channel:id" >&2
+    echo Uses bitcoin-cli to extract the actual txid >&2
+    exit 1
+fi
+
+BLOCK=$(echo "$1" | cut -d: -f1)
+TXNUM=$(echo "$1" | cut -d: -f2)
+
+bitcoin-cli getblock "$(bitcoin-cli getblockhash "$BLOCK")" true | grep '^    "' | head -n "$((TXNUM + 1))" | tail -n 1 | tr -dc '0-9a-f\n'
+