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/*

** $Id: lua.c,v 1.203 2011/12/12 16:34:03 roberto Exp $

** Lua stand-alone interpreter

** See Copyright Notice in lua.h

*/

#include 

#include 

#include 

#include 

#define lua_c

#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)

#define LUA_INIT		"LUA_INIT"

#endif

#define LUA_INITVERSION  \

	LUA_INIT "_" LUA_VERSION_MAJOR "_" LUA_VERSION_MINOR

/*

** lua_stdin_is_tty detects whether the standard input is a 'tty' (that

** is, whether we're running lua interactively).

*/

#if defined(LUA_USE_ISATTY)

#include 

#define lua_stdin_is_tty()      isatty(0)

#elif defined(LUA_WIN)

#include 

#include 

#define lua_stdin_is_tty()      _isatty(_fileno(stdin))

#else

#define lua_stdin_is_tty()      1  /* assume stdin is a tty */

#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_USE_READLINE)

#include 

#include 

#include 

#define lua_readline(L,b,p)     ((void)L, ((b)=readline(p)) != NULL)

#define lua_saveline(L,idx) \

        if (lua_rawlen(L,idx) > 0)  /* non-empty line? */ \

          add_history(lua_tostring(L, idx));  /* add it to history */

#define lua_freeline(L,b)       ((void)L, free(b))

#elif !defined(lua_readline)

#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,idx)     { (void)L; (void)idx; }

#define lua_freeline(L,b)       { (void)L; (void)b; }

#endif

static lua_State *globalL = NULL;

static const char *progname = LUA_PROGNAME;

static void lstop (lua_State *L, lua_Debug *ar) {

  (void)ar;  /* unused arg. */

  lua_sethook(L, NULL, 0, 0);

  luaL_error(L, "interrupted!");

}

static void laction (int i) {

  //signal(i, SIG_DFL);  if another SIGINT happens before lstop,

  //                            terminate process (default action)

  lua_sethook(globalL, lstop, LUA_MASKCALL | LUA_MASKRET | LUA_MASKCOUNT, 1);

}

static void print_usage (const char *badoption) {

  luai_writestringerror("%s: ", progname);

  if (badoption[1] == 'e' || badoption[1] == 'l')

    luai_writestringerror("'%s' needs argument\n", badoption);

  else

    luai_writestringerror("unrecognized option '%s'\n", badoption);

  luai_writestringerror(

  "usage: %s [options] [script [args]]\n"

  "Available options are:\n"

  "  -e stat  execute string " LUA_QL("stat") "\n"

  "  -i       enter interactive mode after executing " LUA_QL("script") "\n"

  "  -l name  require library " LUA_QL("name") "\n"

  "  -v       show version information\n"

  "  -E       ignore environment variables\n"

  "  --       stop handling options\n"

  "  -        stop handling options and execute stdin\n"

  ,

  progname);

}

static void l_message (const char *pname, const char *msg) {

  if (pname) luai_writestringerror("%s: ", pname);

  luai_writestringerror("%s\n", msg);

}

static int report (lua_State *L, int status) {

  if (status != LUA_OK && !lua_isnil(L, -1)) {

    const char *msg = lua_tostring(L, -1);

    if (msg == NULL) msg = "(error object is not a string)";

    l_message(progname, msg);

    lua_pop(L, 1);

    /* force a complete garbage collection in case of errors */

    lua_gc(L, LUA_GCCOLLECT, 0);

  }

  return status;

}

/* the next function is called unprotected, so it must avoid errors */

static void finalreport (lua_State *L, int status) {

  if (status != LUA_OK) {

    const char *msg = (lua_type(L, -1) == LUA_TSTRING) ? lua_tostring(L, -1)

                                                       : NULL;

    if (msg == NULL) msg = "(error object is not a string)";

    l_message(progname, msg);

    lua_pop(L, 1);

  }

}

static int traceback (lua_State *L) {

  const char *msg = lua_tostring(L, 1);

  if (msg)

    luaL_traceback(L, L, msg, 1);

  else if (!lua_isnoneornil(L, 1)) {  /* is there an error object? */

    if (!luaL_callmeta(L, 1, "__tostring"))  /* try its 'tostring' metamethod */

      lua_pushliteral(L, "(no error message)");

  }

  return 1;

}

static int docall (lua_State *L, int narg, int nres) {

  int status;

  int base = lua_gettop(L) - narg;  /* function index */

  lua_pushcfunction(L, traceback);  /* push traceback function */

  lua_insert(L, base);  /* put it under chunk and args */

  globalL = L;  /* to be available to 'laction' */

  //signal(SIGINT, laction);

  status = lua_pcall(L, narg, nres, base);

//  signal(SIGINT, SIG_DFL);

  lua_remove(L, base);  /* remove traceback function */

  return status;

}

static void print_version (void) {

  luai_writestring(LUA_COPYRIGHT, strlen(LUA_COPYRIGHT));

  luai_writeline();

}

static int getargs (lua_State *L, char **argv, int n) {

  int narg;

  int i;

  int argc = 0;

  while (argv[argc]) argc++;  /* count total number of arguments */

  narg = argc - (n + 1);  /* number of arguments to the script */

  luaL_checkstack(L, narg + 3, "too many arguments to script");

  for (i=n+1; i < argc; i++)

    lua_pushstring(L, argv[i]);

  lua_createtable(L, narg, n + 1);

  for (i=0; i < argc; i++) {

    lua_pushstring(L, argv[i]);

    lua_rawseti(L, -2, i - n);

  }

  return narg;

}

static int dofile (lua_State *L, const char *name) {

  int status = luaL_loadfile(L, name);

  if (status == LUA_OK) status = docall(L, 0, 0);

  return report(L, status);

}

static int dostring (lua_State *L, const char *s, const char *name) {

  int status = luaL_loadbuffer(L, s, strlen(s), name);

  if (status == LUA_OK) status = docall(L, 0, 0);

  return report(L, status);

}

static int dolibrary (lua_State *L, const char *name) {

  int status;

  lua_pushglobaltable(L);

  lua_getfield(L, -1, "require");

  lua_pushstring(L, name);

  status = docall(L, 1, 1);

  if (status == LUA_OK) {

    lua_setfield(L, -2, name);  /* global[name] = require return */

    lua_pop(L, 1);  /* remove global table */

  }

  else

    lua_remove(L, -2);  /* remove global table (below error msg.) */

  return report(L, status);

}

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);

  lua_pop(L, 1);  /* remove global */

  return p;

}

/* mark in error messages for incomplete statements */

#define EOFMARK		""

#define marklen		(sizeof(EOFMARK)/sizeof(char) - 1)

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... */

}

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);

  if (lua_readline(L, b, prmt) == 0)

    return 0;  /* no input */

  l = strlen(b);

  if (l > 0 && b[l-1] == '\n')  /* line ends with newline? */

    b[l-1] = '\0';  /* remove it */

  if (firstline && b[0] == '=')  /* first line starts with `=' ? */

    lua_pushfstring(L, "return %s", b+1);  /* change it to `return' */

  else

    lua_pushstring(L, b);

  lua_freeline(L, b);

  return 1;

}

static int loadline (lua_State *L) {

  int status;

  lua_settop(L, 0);

  if (!pushline(L, 1))

    return -1;  /* no input */

  for (;;) {  /* repeat until gets a complete line */

    size_t l;

    const char *line = lua_tolstring(L, 1, &l);

    status = luaL_loadbuffer(L, line, l, "=stdin");

    if (!incomplete(L, status)) break;  /* cannot try to add lines? */

    if (!pushline(L, 0))  /* no more input? */

      return -1;

    lua_pushliteral(L, "\n");  /* add a new line... */

    lua_insert(L, -2);  /* ...between the two lines */

    lua_concat(L, 3);  /* join them */

  }

  lua_saveline(L, 1);

  lua_remove(L, 1);  /* remove line */

  return status;

}

static void dotty (lua_State *L) {

  int status;

  const char *oldprogname = progname;

  progname = NULL;

  while ((status = loadline(L)) != -1) {

    if (status == LUA_OK) status = docall(L, 0, LUA_MULTRET);

    report(L, status);

    if (status == LUA_OK && lua_gettop(L) > 0) {  /* any result to print? */

      luaL_checkstack(L, LUA_MINSTACK, "too many results to print");

      lua_getglobal(L, "print");

      lua_insert(L, 1);

      if (lua_pcall(L, lua_gettop(L)-1, 0, 0) != LUA_OK)

        l_message(progname, lua_pushfstring(L,

                               "error calling " LUA_QL("print") " (%s)",

                               lua_tostring(L, -1)));

    }

  }

  lua_settop(L, 0);  /* clear stack */

  luai_writeline();

  progname = oldprogname;

}

static int handle_script (lua_State *L, char **argv, int n) {

  int status;

  const char *fname;

  int narg = getargs(L, argv, n);  /* collect arguments */

  lua_setglobal(L, "arg");

  fname = argv[n];

  if (strcmp(fname, "-") == 0 && strcmp(argv[n-1], "--") != 0)

    fname = NULL;  /* stdin */

  status = luaL_loadfile(L, fname);

  lua_insert(L, -(narg+1));

  if (status == LUA_OK)

    status = docall(L, narg, LUA_MULTRET);

  else

    lua_pop(L, narg);

  return report(L, status);

}

/* check that argument has no extra characters at the end */

#define noextrachars(x)		{if ((x)[2] != '\0') return -1;}

/* indices of various argument indicators in array args */

#define has_i		0	/* -i */

#define has_v		1	/* -v */

#define has_e		2	/* -e */

#define has_E		3	/* -E */

#define num_has		4	/* number of 'has_*' */

static int collectargs (char **argv, int *args) {

  int i;

  for (i = 1; argv[i] != NULL; i++) {

    if (argv[i][0] != '-')  /* not an option? */

        return i;

    switch (argv[i][1]) {  /* option */

      case '-':

        noextrachars(argv[i]);

        return (argv[i+1] != NULL ? i+1 : 0);

      case '\0':

        return i;

      case 'E':

        args[has_E] = 1;

        break;

      case 'i':

        noextrachars(argv[i]);

        args[has_i] = 1;  /* go through */

      case 'v':

        noextrachars(argv[i]);

        args[has_v] = 1;

        break;

      case 'e':

        args[has_e] = 1;  /* go through */

      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 -(i - 1);  /* no next argument or it is another option */

        }

        break;

      default:  /* invalid option; return its index... */

        return -i;  /* ...as a negative value */

    }

  }

  return 0;

}

static int runargs (lua_State *L, char **argv, int n) {

  int i;

  for (i = 1; i < n; i++) {

    lua_assert(argv[i][0] == '-');

    switch (argv[i][1]) {  /* option */

      case 'e': {

        const char *chunk = argv[i] + 2;

        if (*chunk == '\0') chunk = argv[++i];

        lua_assert(chunk != NULL);

        if (dostring(L, chunk, "=(command line)") != LUA_OK)

          return 0;

        break;

      }

      case 'l': {

        const char *filename = argv[i] + 2;

        if (*filename == '\0') filename = argv[++i];

        lua_assert(filename != NULL);

        if (dolibrary(L, filename) != LUA_OK)

          return 0;  /* stop if file fails */

        break;

      }

      default: break;

    }

  }

  return 1;

}

static int handle_luainit (lua_State *L) {

  const char *name = "=" LUA_INITVERSION;

  const char *init = getenv(name + 1);

  if (init == NULL) {

    name = "=" LUA_INIT;

    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);

}

static int pmain (lua_State *L) {

  int argc = (int)lua_tointeger(L, 1);

  char **argv = (char **)lua_touserdata(L, 2);

  int script;

  int args[num_has];

  args[has_i] = args[has_v] = args[has_e] = args[has_E] = 0;

  if (argv[0] && argv[0][0]) progname = argv[0];

  script = collectargs(argv, args);

  if (script < 0) {  /* invalid arg? */

    print_usage(argv[-script]);

    return 0;

  }

  if (args[has_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");

  }

  /* open standard libraries */

  luaL_checkversion(L);

  lua_gc(L, LUA_GCSTOP, 0);  /* stop collector during initialization */

  luaL_openlibs(L);  /* open libraries */

  lua_gc(L, LUA_GCRESTART, 0);

  if (!args[has_E] && handle_luainit(L) != LUA_OK)

    return 0;  /* error running LUA_INIT */

  /* execute arguments -e and -l */

  if (!runargs(L, argv, (script > 0) ? script : argc)) return 0;

  /* execute main script (if there is one) */

  if (script && handle_script(L, argv, script) != LUA_OK) return 0;

  if (args[has_i])  /* -i option? */

    dotty(L);

  else if (script == 0 && !args[has_e] && !args[has_v]) {  /* no arguments? */

    if (lua_stdin_is_tty()) {

      print_version();

      dotty(L);

    }

    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;

  }

  /* call 'pmain' in protected mode */

  lua_pushcfunction(L, &pmain);

  lua_pushinteger(L, argc);  /* 1st argument */

  lua_pushlightuserdata(L, argv); /* 2nd argument */

  status = lua_pcall(L, 2, 1, 0);

  result = lua_toboolean(L, -1);  /* get result */

  finalreport(L, status);

  lua_close(L);

  return (result && status == LUA_OK) ? EXIT_SUCCESS : EXIT_FAILURE;

}