Tidied up a little

Makefile

@@ -10,3 +10,4 @@ LDPATH = -Ltarget/debug
 
 test: src/test.c include/ecrecover.h target/debug/libecrecover.so
 	$(CC) -o $@ $^ $(CFLAGS) $(LDPATH)
+	./test

README.md

@@ -1,2 +1,14 @@
 # ecrecover
 FFI export of Ethereum's ecrecover
+
+prerequisite:
+- a checked out copy of parity-ethereum (https://github.com/paritytech/parity-ethereum) checked out in the same directory this is
+
+to compile:
+`cargo build`
+
+to test:
+`make` (requires gcc)
+./test
+
+(if you don't see `Test passed` then something went wrong).

src/test.c

@@ -2,22 +2,23 @@
 #include <stdlib.h>
 #include <assert.h>
 #include <string.h>
+#include <stdio.h>
 
 #include "../include/ecrecover.h"
 
-
 char *bin2hex(unsigned char*, int);
-
 unsigned char *hex2bin(const char*);
 
 #define OUTPUT_LENGTH 32
 
 int main(int arc, char **argv) {
+  // copied from Ethereum tests
   unsigned char *input = hex2bin("47173285a8d7341e5e972fc677286384f802f8ef42a5ec5f03bbfa254cb01fad000000000000000000000000000000000000000000000000000000000000001b650acf9d3f5f0a2c799776a1254355d5f4061762a237396a99a0e0e3fc2bcd6729514a0dacb2e623ac4abd157cb18163ff942280db4d5caad66ddf941ba12e03");
   unsigned char *expected = "000000000000000000000000c08b5542d177ac6686946920409741463a15dddb";
   unsigned char *output = malloc(OUTPUT_LENGTH * sizeof(unsigned char));
   ecrecover(input, output);
   assert(strcmp(bin2hex(output, OUTPUT_LENGTH), expected) == 0);
+  printf("Test passed\n");
 }