/*** $Id: lua.c,v 1.160.1.2 2007/12/28 15:32:23 roberto Exp $** Lua stand-alone interpreter** See Copyright Notice in lua.h*/  #include <signal.h>#include <stdio.h>#include <stdlib.h>#include <string.h> #define lua_c #include "lua.h" #include "lauxlib.h"#include "lualib.h"   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 (void) {  fprintf(stderr,  "usage: %s [options] [script [args]].\n"  "Available options are:\n"  "  -e stat  execute string " LUA_QL("stat") "\n"  "  -l name  require library " LUA_QL("name") "\n"  "  -i       enter interactive mode after executing " LUA_QL("script") "\n"  "  -v       show version information\n"  "  --       stop handling options\n"  "  -        execute stdin and stop handling options\n"  ,  progname);  fflush(stderr);}  static void l_message (const char *pname, const char *msg) {  if (pname) fprintf(stderr, "%s: ", pname);  fprintf(stderr, "%s\n", msg);  fflush(stderr);}  static int report (lua_State *L, int status) {  if (status && !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);  }  return status;}  static int traceback (lua_State *L) {  if (!lua_isstring(L, 1))  /* 'message' not a string? */    return 1;  /* keep it intact */  lua_getfield(L, LUA_GLOBALSINDEX, "debug");  if (!lua_istable(L, -1)) {    lua_pop(L, 1);    return 1;  }  lua_getfield(L, -1, "traceback");  if (!lua_isfunction(L, -1)) {    lua_pop(L, 2);    return 1;  }  lua_pushvalue(L, 1);  /* pass error message */  lua_pushinteger(L, 2);  /* skip this function and traceback */  lua_call(L, 2, 1);  /* call debug.traceback */  return 1;}  static int docall (lua_State *L, int narg, int clear) {  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 */  signal(SIGINT, laction);  status = lua_pcall(L, narg, (clear ? 0 : LUA_MULTRET), base);  signal(SIGINT, SIG_DFL);  lua_remove(L, base);  /* remove traceback function */  /* force a complete garbage collection in case of errors */  if (status != 0) lua_gc(L, LUA_GCCOLLECT, 0);  return status;}  static void print_version (void) {  l_message(NULL, LUA_RELEASE "  " LUA_COPYRIGHT);}  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) || docall(L, 0, 1);  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) || docall(L, 0, 1);  return report(L, status);}  static int dolibrary (lua_State *L, const char *name) {  lua_getglobal(L, "require");  lua_pushstring(L, name);  return report(L, docall(L, 1, 1));}  static const char *get_prompt (lua_State *L, int firstline) {  const char *p;  lua_getfield(L, LUA_GLOBALSINDEX, 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;}  static int incomplete (lua_State *L, int status) {  if (status == LUA_ERRSYNTAX) {    size_t lmsg;    const char *msg = lua_tolstring(L, -1, &lmsg);    const char *tp = msg + lmsg - (sizeof(LUA_QL("<eof>")) - 1);    if (strstr(msg, LUA_QL("<eof>")) == tp) {      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 */    status = luaL_loadbuffer(L, lua_tostring(L, 1), lua_strlen(L, 1), "=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 == 0) status = docall(L, 0, 0);    report(L, status);    if (status == 0 && lua_gettop(L) > 0) {  /* any result to print? */      lua_getglobal(L, "print");      lua_insert(L, 1);      if (lua_pcall(L, lua_gettop(L)-1, 0, 0) != 0)        l_message(progname, lua_pushfstring(L,                               "error calling " LUA_QL("print") " (%s)",                               lua_tostring(L, -1)));    }  }  lua_settop(L, 0);  /* clear stack */  fputs("\n", stdout);  fflush(stdout);  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 == 0)    status = docall(L, narg, 0);  else    lua_pop(L, narg);        return report(L, status);}  /* check that argument has no extra characters at the end */#define notail(x)	{if ((x)[2] != '\0') return -1;}  static int collectargs (char **argv, int *pi, int *pv, int *pe) {  int i;  for (i = 1; argv[i] != NULL; i++) {    if (argv[i][0] != '-')  /* not an option? */        return i;    switch (argv[i][1]) {  /* option */      case '-':        notail(argv[i]);        return (argv[i+1] != NULL ? i+1 : 0);      case '\0':        return i;      case 'i':        notail(argv[i]);        *pi = 1;  /* go through */      case 'v':        notail(argv[i]);        *pv = 1;        break;      case 'e':        *pe = 1;  /* go through */      case 'l':        if (argv[i][2] == '\0') {          i++;          if (argv[i] == NULL) return -1;        }        break;      default: return -1;  /* invalid option */    }  }  return 0;}  static int runargs (lua_State *L, char **argv, int n) {  int i;  for (i = 1; i < n; i++) {    if (argv[i] == NULL) continue;    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)") != 0)          return 1;        break;      }      case 'l': {        const char *filename = argv[i] + 2;        if (*filename == '\0') filename = argv[++i];        lua_assert(filename != NULL);        if (dolibrary(L, filename))          return 1;  /* stop if file fails */        break;      }      default: break;    }  }  return 0;}  static int handle_luainit (lua_State *L) {  const char *init = getenv(LUA_INIT);  if (init == NULL) return 0;  /* status OK */  else if (init[0] == '@')    return dofile(L, init+1);  else    return dostring(L, init, "=" LUA_INIT);}  struct Smain {  int argc;  char **argv;  int status;};  static int pmain (lua_State *L) {  struct Smain *s = (struct Smain *)lua_touserdata(L, 1);  char **argv = s->argv;  int script;  int has_i = 0, has_v = 0, has_e = 0;  globalL = L;  if (argv[0] && argv[0][0]) progname = argv[0];  lua_gc(L, LUA_GCSTOP, 0);  /* stop collector during initialization */  luaL_openlibs(L);  /* open libraries */  lua_gc(L, LUA_GCRESTART, 0);  s->status = handle_luainit(L);  if (s->status != 0) return 0;  script = collectargs(argv, &has_i, &has_v, &has_e);  if (script < 0) {  /* invalid args? */    print_usage();    s->status = 1;    return 0;  }  if (has_v) print_version();  s->status = runargs(L, argv, (script > 0) ? script : s->argc);  if (s->status != 0) return 0;  if (script)    s->status = handle_script(L, argv, script);  if (s->status != 0) return 0;  if (has_i)    dotty(L);  else if (script == 0 && !has_e && !has_v) {    if (lua_stdin_is_tty()) {      print_version();      dotty(L);    }    else dofile(L, NULL);  /* executes stdin as a file */  }  return 0;}  int main (int argc, char **argv) {  int status;  struct Smain s;  lua_State *L = lua_open();  /* create state */  if (L == NULL) {    l_message(argv[0], "cannot create state: not enough memory");    return EXIT_FAILURE;  }  s.argc = argc;  s.argv = argv;  status = lua_cpcall(L, &pmain, &s);  report(L, status);  lua_close(L);  return (status || s.status) ? EXIT_FAILURE : EXIT_SUCCESS;}