From 1b9a4467ebd98ece68c25eacfa979929753c6590 Mon Sep 17 00:00:00 2001
From: Shannon Appelcline <shannon.appelcline@gmail.com>
Date: Wed, 12 Aug 2020 14:48:32 -1000
Subject: [PATCH] Create 16_5_replacewithscript.c

---
 src/16_5_replacewithscript.c | 78 ++++++++++++++++++++++++++++++++++++
 1 file changed, 78 insertions(+)
 create mode 100644 src/16_5_replacewithscript.c

diff --git a/src/16_5_replacewithscript.c b/src/16_5_replacewithscript.c
new file mode 100644
index 0000000..ca74236
--- /dev/null
+++ b/src/16_5_replacewithscript.c
@@ -0,0 +1,78 @@
+#include <stdio.h>
+#include <assert.h>
+#include "wally_core.h"
+#include "wally_transaction.h"
+#include "wally_script.h"
+
+int main(int argc, char *argv[]) {
+
+  if (argc != 3) {
+
+    printf("ERROR: Only %i arguments! Correct usage is '%s [transaction hex] [serialized locking script]'\n",argc-1,argv[0]);
+    exit(-1);
+    
+  }
+  char *utxo_hex = argv[1];
+  char *script = argv[2];
+
+  int lw_response;
+  size_t written;
+
+  /* 1. Create the P2SH Script */
+  
+  unsigned char bscript[4];
+  
+  lw_response = wally_hex_to_bytes(script,bscript,4,&written);
+  assert(lw_response == WALLY_OK);
+
+  unsigned char p2sh[WALLY_SCRIPTPUBKEY_P2SH_LEN];
+  			  
+  lw_response = wally_scriptpubkey_p2sh_from_bytes(bscript,sizeof(bscript),WALLY_SCRIPT_HASH160,p2sh,WALLY_SCRIPTPUBKEY_P2SH_LEN,&written);
+  assert(lw_response == WALLY_OK);
+
+  char *pubkey;
+  lw_response = wally_hex_from_bytes(p2sh,sizeof(p2sh),&pubkey);
+
+  /* 2. Create the Transaction */
+  
+  struct wally_tx *tx;
+  lw_response = wally_tx_init_alloc(2,0,1,1,&tx);
+  assert(lw_response == WALLY_OK);
+
+  /* 3. Create the Outputs with the P2SH */
+  
+  struct wally_tx_output *tx_output;
+  lw_response = wally_tx_output_init_alloc(95000,p2sh,sizeof(p2sh),&tx_output);
+  assert(lw_response == WALLY_OK);
+
+  lw_response = wally_tx_add_output(tx,tx_output);
+  assert(lw_response == WALLY_OK);
+
+  /* 4. Create the Inputs based on Hex */
+  
+  struct wally_tx *utxo;
+  lw_response = wally_tx_from_hex(utxo_hex,0,&utxo);
+  assert(lw_response == WALLY_OK);
+
+  struct wally_tx_input *tx_input;
+  lw_response = wally_tx_input_init_alloc(utxo->inputs[0].txhash,sizeof(utxo->inputs[0].txhash),utxo->inputs[0].index,0,utxo->inputs[0].script,utxo->inputs[0].script_len,utxo->inputs[0].witness,&tx_input);
+  assert(lw_response == WALLY_OK);						  
+  lw_response = wally_tx_add_input(tx,tx_input);
+  assert(lw_response == WALLY_OK);
+
+  /* 5. Print It */
+  
+  char *tx_hex;
+  lw_response = wally_tx_to_hex(tx,0, &tx_hex);
+  assert(lw_response == WALLY_OK);
+
+  printf("%s\n",tx_hex);
+
+  wally_free_string(tx_hex);
+  wally_tx_free(tx);
+  wally_tx_input_free(tx_input);
+  wally_tx_output_free(tx_output);
+
+  wally_cleanup(0);  
+
+}