lua.c
(5.0.3)
/*
** $Id: lua.c,v 1.122 2003/04/03 13:34:42 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"
/*
** generic extra include file
*/
#ifdef LUA_USERCONFIG
#include LUA_USERCONFIG
#endif
/*
** definition of `isatty'
*/
#ifdef _POSIX_C_SOURCE
#include <unistd.h>
#define stdin_is_tty() isatty(0)
#else
#define stdin_is_tty() 1 /* assume stdin is a tty */
#endif
#ifndef PROMPT
#define PROMPT "> "
#endif
#ifndef PROMPT2
#define PROMPT2 ">> "
#endif
#ifndef PROGNAME
#define PROGNAME "lua"
#endif
#ifndef lua_userinit
#define lua_userinit(L) openstdlibs(L)
#endif
#ifndef LUA_EXTRALIBS
#define LUA_EXTRALIBS /* empty */
#endif
static lua_State *L = NULL;
static const char *progname = PROGNAME;
static const luaL_reg lualibs[] = {
{"base", luaopen_base},
{"table", luaopen_table},
{"io", luaopen_io},
{"string", luaopen_string},
{"math", luaopen_math},
{"debug", luaopen_debug},
{"loadlib", luaopen_loadlib},
/* add your libraries here */
LUA_EXTRALIBS
{NULL, NULL}
};
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(L, 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"
" - execute stdin as a file\n"
" -e stat execute string `stat'\n"
" -i enter interactive mode after executing `script'\n"
" -l name load and run library `name'\n"
" -v show version information\n"
" -- stop handling options\n" ,
progname);
}
static void l_message (const char *pname, const char *msg) {
if (pname) fprintf(stderr, "%s: ", pname);
fprintf(stderr, "%s\n", msg);
}
static int report (int status) {
const char *msg;
if (status) {
msg = lua_tostring(L, -1);
if (msg == NULL) msg = "(error with no message)";
l_message(progname, msg);
lua_pop(L, 1);
}
return status;
}
static int lcall (int narg, int clear) {
int status;
int base = lua_gettop(L) - narg; /* function index */
lua_pushliteral(L, "_TRACEBACK");
lua_rawget(L, LUA_GLOBALSINDEX); /* get 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 */
return status;
}
static void print_version (void) {
l_message(NULL, LUA_VERSION " " LUA_COPYRIGHT);
}
static void getargs (char *argv[], int n) {
int i;
lua_newtable(L);
for (i=0; argv[i]; i++) {
lua_pushnumber(L, i - n);
lua_pushstring(L, argv[i]);
lua_rawset(L, -3);
}
/* arg.n = maximum index in table `arg' */
lua_pushliteral(L, "n");
lua_pushnumber(L, i-n-1);
lua_rawset(L, -3);
}
static int docall (int status) {
if (status == 0) status = lcall(0, 1);
return report(status);
}
static int file_input (const char *name) {
return docall(luaL_loadfile(L, name));
}
static int dostring (const char *s, const char *name) {
return docall(luaL_loadbuffer(L, s, strlen(s), name));
}
static int load_file (const char *name) {
lua_pushliteral(L, "require");
lua_rawget(L, LUA_GLOBALSINDEX);
if (!lua_isfunction(L, -1)) { /* no `require' defined? */
lua_pop(L, 1);
return file_input(name);
}
else {
lua_pushstring(L, name);
return report(lcall(1, 1));
}
}
/*
** this macro can be used by some `history' system to save lines
** read in manual input
*/
#ifndef lua_saveline
#define lua_saveline(L,line) /* empty */
#endif
/*
** this macro defines a function to show the prompt and reads the
** next line for manual input
*/
#ifndef lua_readline
#define lua_readline(L,prompt) readline(L,prompt)
/* maximum length of an input line */
#ifndef MAXINPUT
#define MAXINPUT 512
#endif
static int readline (lua_State *l, const char *prompt) {
static char buffer[MAXINPUT];
if (prompt) {
fputs(prompt, stdout);
fflush(stdout);
}
if (fgets(buffer, sizeof(buffer), stdin) == NULL)
return 0; /* read fails */
else {
lua_pushstring(l, buffer);
return 1;
}
}
#endif
static const char *get_prompt (int firstline) {
const char *p = NULL;
lua_pushstring(L, firstline ? "_PROMPT" : "_PROMPT2");
lua_rawget(L, LUA_GLOBALSINDEX);
p = lua_tostring(L, -1);
if (p == NULL) p = (firstline ? PROMPT : PROMPT2);
lua_pop(L, 1); /* remove global */
return p;
}
static int incomplete (int status) {
if (status == LUA_ERRSYNTAX &&
strstr(lua_tostring(L, -1), "near `<eof>'") != NULL) {
lua_pop(L, 1);
return 1;
}
else
return 0;
}
static int load_string (void) {
int status;
lua_settop(L, 0);
if (lua_readline(L, get_prompt(1)) == 0) /* no input? */
return -1;
if (lua_tostring(L, -1)[0] == '=') { /* line starts with `=' ? */
lua_pushfstring(L, "return %s", lua_tostring(L, -1)+1);/* `=' -> `return' */
lua_remove(L, -2); /* remove original line */
}
for (;;) { /* repeat until gets a complete line */
status = luaL_loadbuffer(L, lua_tostring(L, 1), lua_strlen(L, 1), "=stdin");
if (!incomplete(status)) break; /* cannot try to add lines? */
if (lua_readline(L, get_prompt(0)) == 0) /* no more input? */
return -1;
lua_concat(L, lua_gettop(L)); /* join lines */
}
lua_saveline(L, lua_tostring(L, 1));
lua_remove(L, 1); /* remove line */
return status;
}
static void manual_input (void) {
int status;
const char *oldprogname = progname;
progname = NULL;
while ((status = load_string()) != -1) {
if (status == 0) status = lcall(0, 0);
report(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 `print' (%s)",
lua_tostring(L, -1)));
}
}
lua_settop(L, 0); /* clear stack */
fputs("\n", stdout);
progname = oldprogname;
}
static int handle_argv (char *argv[], int *interactive) {
if (argv[1] == NULL) { /* no more arguments? */
if (stdin_is_tty()) {
print_version();
manual_input();
}
else
file_input(NULL); /* executes stdin as a file */
}
else { /* other arguments; loop over them */
int i;
for (i = 1; argv[i] != NULL; i++) {
if (argv[i][0] != '-') break; /* not an option? */
switch (argv[i][1]) { /* option */
case '-': { /* `--' */
if (argv[i][2] != '\0') {
print_usage();
return 1;
}
i++; /* skip this argument */
goto endloop; /* stop handling arguments */
}
case '\0': {
file_input(NULL); /* executes stdin as a file */
break;
}
case 'i': {
*interactive = 1;
break;
}
case 'v': {
print_version();
break;
}
case 'e': {
const char *chunk = argv[i] + 2;
if (*chunk == '\0') chunk = argv[++i];
if (chunk == NULL) {
print_usage();
return 1;
}
if (dostring(chunk, "=<command line>") != 0)
return 1;
break;
}
case 'l': {
const char *filename = argv[i] + 2;
if (*filename == '\0') filename = argv[++i];
if (filename == NULL) {
print_usage();
return 1;
}
if (load_file(filename))
return 1; /* stop if file fails */
break;
}
case 'c': {
l_message(progname, "option `-c' is deprecated");
break;
}
case 's': {
l_message(progname, "option `-s' is deprecated");
break;
}
default: {
print_usage();
return 1;
}
}
} endloop:
if (argv[i] != NULL) {
const char *filename = argv[i];
getargs(argv, i); /* collect arguments */
lua_setglobal(L, "arg");
return file_input(filename); /* stop scanning arguments */
}
}
return 0;
}
static void openstdlibs (lua_State *l) {
const luaL_reg *lib = lualibs;
for (; lib->func; lib++) {
lib->func(l); /* open library */
lua_settop(l, 0); /* discard any results */
}
}
static int handle_luainit (void) {
const char *init = getenv("LUA_INIT");
if (init == NULL) return 0; /* status OK */
else if (init[0] == '@')
return file_input(init+1);
else
return dostring(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);
int status;
int interactive = 0;
if (s->argv[0] && s->argv[0][0]) progname = s->argv[0];
L = l;
lua_userinit(l); /* open libraries */
status = handle_luainit();
if (status == 0) {
status = handle_argv(s->argv, &interactive);
if (status == 0 && interactive) manual_input();
}
s->status = status;
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(status);
lua_close(l);
return (status || s.status) ? EXIT_FAILURE : EXIT_SUCCESS;
}