add util script for generating header for binaries

Author: leafo

bin/util/file_to_header.lua

@@ -0,0 +1,42 @@
+-- this script is used to convert a source input file into a C header to embed
+-- that file as a string. Works the same as xxd -i
+
+local input = ...
+
+local function read_file(file_path)
+  local file = assert(io.open(file_path, "rb"))
+  local content = file:read("*a")
+  file:close()
+  return content
+end
+
+local function generate_c_header(input_file)
+    local function byte_to_hex(byte)
+      return string.format("0x%02x", byte:byte())
+    end
+
+    local function sanitize_name(name)
+      return (name:gsub("[^%w_]", "_"))
+    end
+
+    local data = read_file(input_file)
+    local name = sanitize_name(input_file)
+    local header = {}
+
+    table.insert(header, string.format("unsigned char %s[] = {", name))
+    for i = 1, #data do
+        if i % 16 == 1 then
+            table.insert(header, "\n  ")
+        end
+        table.insert(header, byte_to_hex(data:sub(i, i)))
+        if i ~= #data then
+            table.insert(header, ", ")
+        end
+    end
+    table.insert(header, "\n};\n")
+    table.insert(header, string.format("unsigned int %s_len = %d;\n", name, #data))
+
+    return table.concat(header)
+end
+
+print(generate_c_header(input))