///*
//** $Id: lua.c,v 1.230 2017/01/12 17:14:26 roberto Exp $
//** Lua stand-alone interpreter
//** See Copyright Notice in lua.h
//*/
//
//#define lua_c
//
//#include "lprefix.h"
//
//
//#include <signal.h>
//#include <stdio.h>
//#include <stdlib.h>
//#include <string.h>
//
//#include "lua.h"
//
//#include "lauxlib.h"
//#include "lualib.h"
//
//
//
//#if !defined(LUA_PROMPT)
//#define LUA_PROMPT		"> "
//#define LUA_PROMPT2		">> "
//#endif
//
//#if !defined(LUA_PROGNAME)
//#define LUA_PROGNAME		"lua"
//#endif
//
//#if !defined(LUA_MAXINPUT)
//#define LUA_MAXINPUT		512
//#endif
//
//#if !defined(LUA_INIT_VAR)
//#define LUA_INIT_VAR		"LUA_INIT"
//#endif
//
//#define LUA_INITVARVERSION	LUA_INIT_VAR LUA_VERSUFFIX
//
//
///*
//** lua_stdin_is_tty detects whether the standard input is a 'tty' (that
//** is, whether we're running lua interactively).
//*/
//#if !defined(lua_stdin_is_tty)	/* { */
//
//#if defined(LUA_USE_POSIX)	/* { */
//
//#include <unistd.h>
//#define lua_stdin_is_tty()	isatty(0)
//
//#elif defined(LUA_USE_WINDOWS)	/* }{ */
//
//#include <io.h>
//#include <windows.h>
//
//#define lua_stdin_is_tty()	_isatty(_fileno(stdin))
//
//#else				/* }{ */
//
///* ISO C definition */
//#define lua_stdin_is_tty()	1  /* assume stdin is a tty */
//
//#endif				/* } */
//
//#endif				/* } */
//
//
///*
//** lua_readline defines how to show a prompt and then read a line from
//** the standard input.
//** lua_saveline defines how to "save" a read line in a "history".
//** lua_freeline defines how to free a line read by lua_readline.
//*/
//#if !defined(lua_readline)	/* { */
//
//#if defined(LUA_USE_READLINE)	/* { */
//
//#include <readline/readline.h>
//#include <readline/history.h>
//#define lua_readline(L,b,p)	((void)L, ((b)=readline(p)) != NULL)
//#define lua_saveline(L,line)	((void)L, add_history(line))
//#define lua_freeline(L,b)	((void)L, free(b))
//
//#else				/* }{ */
//
//#define lua_readline(L,b,p) \
//        ((void)L, fputs(p, stdout), fflush(stdout),  /* show prompt */ \
//        fgets(b, LUA_MAXINPUT, stdin) != NULL)  /* get line */
//#define lua_saveline(L,line)	{ (void)L; (void)line; }
//#define lua_freeline(L,b)	{ (void)L; (void)b; }
//
//#endif				/* } */
//
//#endif				/* } */
//
//
//
//
//static lua_State *globalL = NULL;
//
//static const char *progname = LUA_PROGNAME;
//
//
///*
//** Hook set by signal function to stop the interpreter.
//*/
//static void lstop (lua_State *L, lua_Debug *ar) {
//  (void)ar;  /* unused arg. */
//  lua_sethook(L, NULL, 0, 0);  /* reset hook */
//  luaL_error(L, "interrupted!");
//}
//
//
///*
//** Function to be called at a C signal. Because a C signal cannot
//** just change a Lua state (as there is no proper synchronization),
//** this function only sets a hook that, when called, will stop the
//** interpreter.
//*/
//static void laction (int i) {
//  signal(i, SIG_DFL); /* if another SIGINT happens, terminate process */
//  lua_sethook(globalL, lstop, LUA_MASKCALL | LUA_MASKRET | LUA_MASKCOUNT, 1);
//}
//
//
//static void print_usage (const char *badoption) {
//  lua_writestringerror("%s: ", progname);
//  if (badoption[1] == 'e' || badoption[1] == 'l')
//    lua_writestringerror("'%s' needs argument\n", badoption);
//  else
//    lua_writestringerror("unrecognized option '%s'\n", badoption);
//  lua_writestringerror(
//  "usage: %s [options] [script [args]]\n"
//  "Available options are:\n"
//  "  -e stat  execute string 'stat'\n"
//  "  -i       enter interactive mode after executing 'script'\n"
//  "  -l name  require library 'name'\n"
//  "  -v       show version information\n"
//  "  -E       ignore environment variables\n"
//  "  --       stop handling options\n"
//  "  -        stop handling options and execute stdin\n"
//  ,
//  progname);
//}
//
//
///*
//** Prints an error message, adding the program name in front of it
//** (if present)
//*/
//static void l_message (const char *pname, const char *msg) {
//  if (pname) lua_writestringerror("%s: ", pname);
//  lua_writestringerror("%s\n", msg);
//}
//
//
///*
//** Check whether 'status' is not OK and, if so, prints the error
//** message on the top of the stack. It assumes that the error object
//** is a string, as it was either generated by Lua or by 'msghandler'.
//*/
//static int report (lua_State *L, int status) {
//  if (status != LUA_OK) {
//    const char *msg = lua_tostring(L, -1);
//    l_message(progname, msg);
//    lua_pop(L, 1);  /* remove message */
//  }
//  return status;
//}
//
//
///*
//** Message handler used to run all chunks
//*/
//static int msghandler (lua_State *L) {
//  const char *msg = lua_tostring(L, 1);
//  if (msg == NULL) {  /* is error object not a string? */
//    if (luaL_callmeta(L, 1, "__tostring") &&  /* does it have a metamethod */
//        lua_type(L, -1) == LUA_TSTRING)  /* that produces a string? */
//      return 1;  /* that is the message */
//    else
//      msg = lua_pushfstring(L, "(error object is a %s value)",
//                               luaL_typename(L, 1));
//  }
//  luaL_traceback(L, L, msg, 1);  /* append a standard traceback */
//  return 1;  /* return the traceback */
//}
//
//
///*
//** Interface to 'lua_pcall', which sets appropriate message function
//** and C-signal handler. Used to run all chunks.
//*/
//static int docall (lua_State *L, int narg, int nres) {
//  int status;
//  int base = lua_gettop(L) - narg;  /* function index */
//  lua_pushcfunction(L, msghandler);  /* push message handler */
//  lua_insert(L, base);  /* put it under function and args */
//  globalL = L;  /* to be available to 'laction' */
//  signal(SIGINT, laction);  /* set C-signal handler */
//  status = lua_pcall(L, narg, nres, base);
//  signal(SIGINT, SIG_DFL); /* reset C-signal handler */
//  lua_remove(L, base);  /* remove message handler from the stack */
//  return status;
//}
//
//
//static void print_version (void) {
//  lua_writestring(LUA_COPYRIGHT, strlen(LUA_COPYRIGHT));
//  lua_writeline();
//}
//
//
///*
//** Create the 'arg' table, which stores all arguments from the
//** command line ('argv'). It should be aligned so that, at index 0,
//** it has 'argv[script]', which is the script name. The arguments
//** to the script (everything after 'script') go to positive indices;
//** other arguments (before the script name) go to negative indices.
//** If there is no script name, assume interpreter's name as base.
//*/
//static void createargtable (lua_State *L, char **argv, int argc, int script) {
//  int i, narg;
//  if (script == argc) script = 0;  /* no script name? */
//  narg = argc - (script + 1);  /* number of positive indices */
//  lua_createtable(L, narg, script + 1);
//  for (i = 0; i < argc; i++) {
//    lua_pushstring(L, argv[i]);
//    lua_rawseti(L, -2, i - script);
//  }
//  lua_setglobal(L, "arg");
//}
//
//
//static int dochunk (lua_State *L, int status) {
//  if (status == LUA_OK) status = docall(L, 0, 0);
//  return report(L, status);
//}
//
//
//static int dofile (lua_State *L, const char *name) {
//  return dochunk(L, luaL_loadfile(L, name));
//}
//
//
//static int dostring (lua_State *L, const char *s, const char *name) {
//  return dochunk(L, luaL_loadbuffer(L, s, strlen(s), name));
//}
//
//
///*
//** Calls 'require(name)' and stores the result in a global variable
//** with the given name.
//*/
//static int dolibrary (lua_State *L, const char *name) {
//  int status;
//  lua_getglobal(L, "require");
//  lua_pushstring(L, name);
//  status = docall(L, 1, 1);  /* call 'require(name)' */
//  if (status == LUA_OK)
//    lua_setglobal(L, name);  /* global[name] = require return */
//  return report(L, status);
//}
//
//
///*
//** Returns the string to be used as a prompt by the interpreter.
//*/
//static const char *get_prompt (lua_State *L, int firstline) {
//  const char *p;
//  lua_getglobal(L, firstline ? "_PROMPT" : "_PROMPT2");
//  p = lua_tostring(L, -1);
//  if (p == NULL) p = (firstline ? LUA_PROMPT : LUA_PROMPT2);
//  return p;
//}
//
///* mark in error messages for incomplete statements */
//#define EOFMARK		"<eof>"
//#define marklen		(sizeof(EOFMARK)/sizeof(char) - 1)
//
//
///*
//** Check whether 'status' signals a syntax error and the error
//** message at the top of the stack ends with the above mark for
//** incomplete statements.
//*/
//static int incomplete (lua_State *L, int status) {
//  if (status == LUA_ERRSYNTAX) {
//    size_t lmsg;
//    const char *msg = lua_tolstring(L, -1, &lmsg);
//    if (lmsg >= marklen && strcmp(msg + lmsg - marklen, EOFMARK) == 0) {
//      lua_pop(L, 1);
//      return 1;
//    }
//  }
//  return 0;  /* else... */
//}
//
//
///*
//** Prompt the user, read a line, and push it into the Lua stack.
//*/
//static int pushline (lua_State *L, int firstline) {
//  char buffer[LUA_MAXINPUT];
//  char *b = buffer;
//  size_t l;
//  const char *prmt = get_prompt(L, firstline);
//  int readstatus = lua_readline(L, b, prmt);
//  if (readstatus == 0)
//    return 0;  /* no input (prompt will be popped by caller) */
//  lua_pop(L, 1);  /* remove prompt */
//  l = strlen(b);
//  if (l > 0 && b[l-1] == '\n')  /* line ends with newline? */
//    b[--l] = '\0';  /* remove it */
//  if (firstline && b[0] == '=')  /* for compatibility with 5.2, ... */
//    lua_pushfstring(L, "return %s", b + 1);  /* change '=' to 'return' */
//  else
//    lua_pushlstring(L, b, l);
//  lua_freeline(L, b);
//  return 1;
//}
//
//
///*
//** Try to compile line on the stack as 'return <line>;'; on return, stack
//** has either compiled chunk or original line (if compilation failed).
//*/
//static int addreturn (lua_State *L) {
//  const char *line = lua_tostring(L, -1);  /* original line */
//  const char *retline = lua_pushfstring(L, "return %s;", line);
//  int status = luaL_loadbuffer(L, retline, strlen(retline), "=stdin");
//  if (status == LUA_OK) {
//    lua_remove(L, -2);  /* remove modified line */
//    if (line[0] != '\0')  /* non empty? */
//      lua_saveline(L, line);  /* keep history */
//  }
//  else
//    lua_pop(L, 2);  /* pop result from 'luaL_loadbuffer' and modified line */
//  return status;
//}
//
//
///*
//** Read multiple lines until a complete Lua statement
//*/
//static int multiline (lua_State *L) {
//  for (;;) {  /* repeat until gets a complete statement */
//    size_t len;
//    const char *line = lua_tolstring(L, 1, &len);  /* get what it has */
//    int status = luaL_loadbuffer(L, line, len, "=stdin");  /* try it */
//    if (!incomplete(L, status) || !pushline(L, 0)) {
//      lua_saveline(L, line);  /* keep history */
//      return status;  /* cannot or should not try to add continuation line */
//    }
//    lua_pushliteral(L, "\n");  /* add newline... */
//    lua_insert(L, -2);  /* ...between the two lines */
//    lua_concat(L, 3);  /* join them */
//  }
//}
//
//
///*
//** Read a line and try to load (compile) it first as an expression (by
//** adding "return " in front of it) and second as a statement. Return
//** the final status of load/call with the resulting function (if any)
//** in the top of the stack.
//*/
//static int loadline (lua_State *L) {
//  int status;
//  lua_settop(L, 0);
//  if (!pushline(L, 1))
//    return -1;  /* no input */
//  if ((status = addreturn(L)) != LUA_OK)  /* 'return ...' did not work? */
//    status = multiline(L);  /* try as command, maybe with continuation lines */
//  lua_remove(L, 1);  /* remove line from the stack */
//  lua_assert(lua_gettop(L) == 1);
//  return status;
//}
//
//
///*
//** Prints (calling the Lua 'print' function) any values on the stack
//*/
//static void l_print (lua_State *L) {
//  int n = lua_gettop(L);
//  if (n > 0) {  /* any result to be printed? */
//    luaL_checkstack(L, LUA_MINSTACK, "too many results to print");
//    lua_getglobal(L, "print");
//    lua_insert(L, 1);
//    if (lua_pcall(L, n, 0, 0) != LUA_OK)
//      l_message(progname, lua_pushfstring(L, "error calling 'print' (%s)",
//                                             lua_tostring(L, -1)));
//  }
//}
//
//
///*
//** Do the REPL: repeatedly read (load) a line, evaluate (call) it, and
//** print any results.
//*/
//static void doREPL (lua_State *L) {
//  int status;
//  const char *oldprogname = progname;
//  progname = NULL;  /* no 'progname' on errors in interactive mode */
//  while ((status = loadline(L)) != -1) {
//    if (status == LUA_OK)
//      status = docall(L, 0, LUA_MULTRET);
//    if (status == LUA_OK) l_print(L);
//    else report(L, status);
//  }
//  lua_settop(L, 0);  /* clear stack */
//  lua_writeline();
//  progname = oldprogname;
//}
//
//
///*
//** Push on the stack the contents of table 'arg' from 1 to #arg
//*/
//static int pushargs (lua_State *L) {
//  int i, n;
//  if (lua_getglobal(L, "arg") != LUA_TTABLE)
//    luaL_error(L, "'arg' is not a table");
//  n = (int)luaL_len(L, -1);
//  luaL_checkstack(L, n + 3, "too many arguments to script");
//  for (i = 1; i <= n; i++)
//    lua_rawgeti(L, -i, i);
//  lua_remove(L, -i);  /* remove table from the stack */
//  return n;
//}
//
//
//static int handle_script (lua_State *L, char **argv) {
//  int status;
//  const char *fname = argv[0];
//  if (strcmp(fname, "-") == 0 && strcmp(argv[-1], "--") != 0)
//    fname = NULL;  /* stdin */
//  status = luaL_loadfile(L, fname);
//  if (status == LUA_OK) {
//    int n = pushargs(L);  /* push arguments to script */
//    status = docall(L, n, LUA_MULTRET);
//  }
//  return report(L, status);
//}
//
//
//
///* bits of various argument indicators in 'args' */
//#define has_error	1	/* bad option */
//#define has_i		2	/* -i */
//#define has_v		4	/* -v */
//#define has_e		8	/* -e */
//#define has_E		16	/* -E */
//
///*
//** Traverses all arguments from 'argv', returning a mask with those
//** needed before running any Lua code (or an error code if it finds
//** any invalid argument). 'first' returns the first not-handled argument
//** (either the script name or a bad argument in case of error).
//*/
//static int collectargs (char **argv, int *first) {
//  int args = 0;
//  int i;
//  for (i = 1; argv[i] != NULL; i++) {
//    *first = i;
//    if (argv[i][0] != '-')  /* not an option? */
//        return args;  /* stop handling options */
//    switch (argv[i][1]) {  /* else check option */
//      case '-':  /* '--' */
//        if (argv[i][2] != '\0')  /* extra characters after '--'? */
//          return has_error;  /* invalid option */
//        *first = i + 1;
//        return args;
//      case '\0':  /* '-' */
//        return args;  /* script "name" is '-' */
//      case 'E':
//        if (argv[i][2] != '\0')  /* extra characters after 1st? */
//          return has_error;  /* invalid option */
//        args |= has_E;
//        break;
//      case 'i':
//        args |= has_i;  /* (-i implies -v) *//* FALLTHROUGH */
//      case 'v':
//        if (argv[i][2] != '\0')  /* extra characters after 1st? */
//          return has_error;  /* invalid option */
//        args |= has_v;
//        break;
//      case 'e':
//        args |= has_e;  /* FALLTHROUGH */
//      case 'l':  /* both options need an argument */
//        if (argv[i][2] == '\0') {  /* no concatenated argument? */
//          i++;  /* try next 'argv' */
//          if (argv[i] == NULL || argv[i][0] == '-')
//            return has_error;  /* no next argument or it is another option */
//        }
//        break;
//      default:  /* invalid option */
//        return has_error;
//    }
//  }
//  *first = i;  /* no script name */
//  return args;
//}
//
//
///*
//** Processes options 'e' and 'l', which involve running Lua code.
//** Returns 0 if some code raises an error.
//*/
//static int runargs (lua_State *L, char **argv, int n) {
//  int i;
//  for (i = 1; i < n; i++) {
//    int option = argv[i][1];
//    lua_assert(argv[i][0] == '-');  /* already checked */
//    if (option == 'e' || option == 'l') {
//      int status;
//      const char *extra = argv[i] + 2;  /* both options need an argument */
//      if (*extra == '\0') extra = argv[++i];
//      lua_assert(extra != NULL);
//      status = (option == 'e')
//               ? dostring(L, extra, "=(command line)")
//               : dolibrary(L, extra);
//      if (status != LUA_OK) return 0;
//    }
//  }
//  return 1;
//}
//
//
//
//static int handle_luainit (lua_State *L) {
//  const char *name = "=" LUA_INITVARVERSION;
//  const char *init = getenv(name + 1);
//  if (init == NULL) {
//    name = "=" LUA_INIT_VAR;
//    init = getenv(name + 1);  /* try alternative name */
//  }
//  if (init == NULL) return LUA_OK;
//  else if (init[0] == '@')
//    return dofile(L, init+1);
//  else
//    return dostring(L, init, name);
//}
//
//
///*
//** Main body of stand-alone interpreter (to be called in protected mode).
//** Reads the options and handles them all.
//*/
//static int pmain (lua_State *L) {
//  int argc = (int)lua_tointeger(L, 1);
//  char **argv = (char **)lua_touserdata(L, 2);
//  int script;
//  int args = collectargs(argv, &script);
//  luaL_checkversion(L);  /* check that interpreter has correct version */
//  if (argv[0] && argv[0][0]) progname = argv[0];
//  if (args == has_error) {  /* bad arg? */
//    print_usage(argv[script]);  /* 'script' has index of bad arg. */
//    return 0;
//  }
//  if (args & has_v)  /* option '-v'? */
//    print_version();
//  if (args & has_E) {  /* option '-E'? */
//    lua_pushboolean(L, 1);  /* signal for libraries to ignore env. vars. */
//    lua_setfield(L, LUA_REGISTRYINDEX, "LUA_NOENV");
//  }
//  luaL_openlibs(L);  /* open standard libraries */
//  createargtable(L, argv, argc, script);  /* create table 'arg' */
//  if (!(args & has_E)) {  /* no option '-E'? */
//    if (handle_luainit(L) != LUA_OK)  /* run LUA_INIT */
//      return 0;  /* error running LUA_INIT */
//  }
//  if (!runargs(L, argv, script))  /* execute arguments -e and -l */
//    return 0;  /* something failed */
//  if (script < argc &&  /* execute main script (if there is one) */
//      handle_script(L, argv + script) != LUA_OK)
//    return 0;
//  if (args & has_i)  /* -i option? */
//    doREPL(L);  /* do read-eval-print loop */
//  else if (script == argc && !(args & (has_e | has_v))) {  /* no arguments? */
//    if (lua_stdin_is_tty()) {  /* running in interactive mode? */
//      print_version();
//      doREPL(L);  /* do read-eval-print loop */
//    }
//    else dofile(L, NULL);  /* executes stdin as a file */
//  }
//  lua_pushboolean(L, 1);  /* signal no errors */
//  return 1;
//}
//
//
//int main (int argc, char **argv) {
//  int status, result;
//  lua_State *L = luaL_newstate();  /* create state */
//  if (L == NULL) {
//    l_message(argv[0], "cannot create state: not enough memory");
//    return EXIT_FAILURE;
//  }
//  lua_pushcfunction(L, &pmain);  /* to call 'pmain' in protected mode */
//  lua_pushinteger(L, argc);  /* 1st argument */
//  lua_pushlightuserdata(L, argv); /* 2nd argument */
//  status = lua_pcall(L, 2, 1, 0);  /* do the call */
//  result = lua_toboolean(L, -1);  /* get result */
//  report(L, status);
//  lua_close(L);
//  return (result && status == LUA_OK) ? EXIT_SUCCESS : EXIT_FAILURE;
//}
//