/*

** $Id: lua.c,v 1.206.1.1 2013/04/12 18:48:47 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"

#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 <unistd.h>

#define lua_stdin_is_tty() isatty(0)

#elif defined(LUA_WIN)

#include <io.h>

#include <stdio.h>

#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 <stdio.h>

#include <readline/readline.h>

#include <readline/history.h>

#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_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);

}

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)

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);

int readstatus = lua_readline(L, b, prmt);

lua_pop(L, 1); /* remove result from 'get_prompt' */

if (readstatus == 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;

}