feat: Redbean => add new UuidV4 method

tool/net/definitions.lua

@@ -1977,6 +1977,10 @@ function VisualizeControlCodes(str) end
 ---@nodiscard
 function Underlong(str) end
 
+--- Generate a uuid_v4
+--- @return string
+function UuidV4() end
+
 ---@param x integer
 ---@return integer # position of first bit set.
 --- Passing `0` will raise an error. Same as the Intel x86 instruction BSF.

tool/net/lfuncs.c

@@ -72,6 +72,7 @@
 #include "third_party/mbedtls/sha512.h"
 #include "third_party/musl/netdb.h"
 #include "third_party/zlib/zlib.h"
+#include <time.h>
 
 static int Rdpid(void) {
 #ifdef __x86_64__
@@ -829,6 +830,30 @@ int LuaVisualizeControlCodes(lua_State *L) {
   return LuaCoder(L, VisualizeControlCodes);
 }
 
+int LuaUuidV4(lua_State *L) {
+  char *template = "xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx";
+  char *uuid = (char *)malloc(strlen(template) + 1);
+  if (uuid == NULL) {
+      return NULL; // Memory allocation failed
+  }
+
+  srand(time(NULL));
+
+  for (int i = 0; i < strlen(template); i++) {
+      char c = template[i];
+      if (c == 'x') {
+          uuid[i] = (rand() % 16 < 10) ? (rand() % 10 + '0') : (rand() % 6 + 'a');
+      } else if (c == 'y') {
+          uuid[i] = (rand() % 4 + '8');
+      } else {
+          uuid[i] = c;
+      }
+  }
+  uuid[strlen(template)] = '\0';
+  lua_pushfstring(L, uuid);
+  return 1;
+}
+
 static dontinline int LuaHasherImpl(lua_State *L, size_t k,
                                     int H(const void *, size_t, uint8_t *)) {
   size_t n;

tool/net/lfuncs.h

@@ -90,6 +90,7 @@ int LuaSleep(lua_State *);
 int LuaSlurp(lua_State *);
 int LuaUncompress(lua_State *);
 int LuaUnderlong(lua_State *);
+int LuaUuidV4(lua_State *);
 int LuaVisualizeControlCodes(lua_State *);
 
 void LuaPushUrlView(lua_State *, struct UrlView *);

tool/net/redbean.c

@@ -5287,6 +5287,7 @@ static const luaL_Reg kLuaFuncs[] = {
     {"StoreAsset", LuaStoreAsset},                              //
     {"Uncompress", LuaUncompress},                              //
     {"Underlong", LuaUnderlong},                                //
+    {"UuidV4", LuaUuidV4},                                      //
     {"VisualizeControlCodes", LuaVisualizeControlCodes},        //
     {"Write", LuaWrite},                                        //
     {"bin", LuaBin},                                            //