lua.c
(4.0.1)
/*
** $Id: lua.c,v 1.55 2000/10/20 16:36:32 roberto Exp $
** Lua stand-alone interpreter
** See Copyright Notice in lua.h
*/
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "lua.h"
#include "luadebug.h"
#include "lualib.h"
static lua_State *L = NULL;
#ifndef PROMPT
#define PROMPT "> "
#endif
#ifdef _POSIX_SOURCE
#include <unistd.h>
#else
static int isatty (int x) { return x==0; } /* assume stdin is a tty */
#endif
/*
** global options
*/
struct Options {
int toclose;
int stacksize;
};
typedef void (*handler)(int); /* type for signal actions */
static void laction (int i);
static lua_Hook old_linehook = NULL;
static lua_Hook old_callhook = NULL;
static void userinit (void) {
lua_baselibopen(L);
lua_iolibopen(L);
lua_strlibopen(L);
lua_mathlibopen(L);
lua_dblibopen(L);
/* add your libraries here */
}
static handler lreset (void) {
return signal(SIGINT, laction);
}
static void lstop (void) {
lua_setlinehook(L, old_linehook);
lua_setcallhook(L, old_callhook);
lreset();
lua_error(L, "interrupted!");
}
static void laction (int i) {
(void)i; /* to avoid warnings */
signal(SIGINT, SIG_DFL); /* if another SIGINT happens before lstop,
terminate process (default action) */
old_linehook = lua_setlinehook(L, (lua_Hook)lstop);
old_callhook = lua_setcallhook(L, (lua_Hook)lstop);
}
static int ldo (int (*f)(lua_State *l, const char *), const char *name) {
int res;
handler h = lreset();
int top = lua_gettop(L);
res = f(L, name); /* dostring | dofile */
lua_settop(L, top); /* remove eventual results */
signal(SIGINT, h); /* restore old action */
/* Lua gives no message in such cases, so lua.c provides one */
if (res == LUA_ERRMEM) {
fprintf(stderr, "lua: memory allocation error\n");
}
else if (res == LUA_ERRERR)
fprintf(stderr, "lua: error in error message\n");
return res;
}
static void print_message (void) {
fprintf(stderr,
"usage: lua [options]. Available options are:\n"
" - execute stdin as a file\n"
" -c close Lua when exiting\n"
" -e stat execute string `stat'\n"
" -f name execute file `name' with remaining arguments in table `arg'\n"
" -i enter interactive mode with prompt\n"
" -q enter interactive mode without prompt\n"
" -sNUM set stack size to NUM (must be the first option)\n"
" -v print version information\n"
" a=b set global `a' to string `b'\n"
" name execute file `name'\n"
);
}
static void print_version (void) {
printf("%.80s %.80s\n", LUA_VERSION, LUA_COPYRIGHT);
}
static void assign (char *arg) {
char *eq = strchr(arg, '=');
*eq = '\0'; /* spilt `arg' in two strings (name & value) */
lua_pushstring(L, eq+1);
lua_setglobal(L, arg);
}
static void getargs (char *argv[]) {
int i;
lua_newtable(L);
for (i=0; argv[i]; i++) {
/* arg[i] = argv[i] */
lua_pushnumber(L, i);
lua_pushstring(L, argv[i]);
lua_settable(L, -3);
}
/* arg.n = maximum index in table `arg' */
lua_pushstring(L, "n");
lua_pushnumber(L, i-1);
lua_settable(L, -3);
}
static int l_getargs (lua_State *l) {
char **argv = (char **)lua_touserdata(l, -1);
getargs(argv);
return 1;
}
static int file_input (const char *argv) {
int result = ldo(lua_dofile, argv);
if (result) {
if (result == LUA_ERRFILE) {
fprintf(stderr, "lua: cannot execute file ");
perror(argv);
}
return EXIT_FAILURE;
}
else
return EXIT_SUCCESS;
}
/* maximum length of an input string */
#ifndef MAXINPUT
#define MAXINPUT BUFSIZ
#endif
static void manual_input (int version, int prompt) {
int cont = 1;
if (version) print_version();
while (cont) {
char buffer[MAXINPUT];
int i = 0;
if (prompt) {
const char *s;
lua_getglobal(L, "_PROMPT");
s = lua_tostring(L, -1);
if (!s) s = PROMPT;
fputs(s, stdout);
lua_pop(L, 1); /* remove global */
}
for(;;) {
int c = getchar();
if (c == EOF) {
cont = 0;
break;
}
else if (c == '\n') {
if (i>0 && buffer[i-1] == '\\')
buffer[i-1] = '\n';
else break;
}
else if (i >= MAXINPUT-1) {
fprintf(stderr, "lua: input line too long\n");
break;
}
else buffer[i++] = (char)c;
}
buffer[i] = '\0';
ldo(lua_dostring, buffer);
lua_settop(L, 0); /* remove eventual results */
}
printf("\n");
}
static int handle_argv (char *argv[], struct Options *opt) {
if (opt->stacksize > 0) argv++; /* skip option `-s' (if present) */
if (*argv == NULL) { /* no more arguments? */
if (isatty(0)) {
manual_input(1, 1);
}
else
ldo(lua_dofile, NULL); /* executes stdin as a file */
}
else { /* other arguments; loop over them */
int i;
for (i = 0; argv[i] != NULL; i++) {
if (argv[i][0] != '-') { /* not an option? */
if (strchr(argv[i], '='))
assign(argv[i]);
else
if (file_input(argv[i]) != EXIT_SUCCESS)
return EXIT_FAILURE; /* stop if file fails */
}
else switch (argv[i][1]) { /* option */
case 0: {
ldo(lua_dofile, NULL); /* executes stdin as a file */
break;
}
case 'i': {
manual_input(0, 1);
break;
}
case 'q': {
manual_input(0, 0);
break;
}
case 'c': {
opt->toclose = 1;
break;
}
case 'v': {
print_version();
break;
}
case 'e': {
i++;
if (argv[i] == NULL) {
print_message();
return EXIT_FAILURE;
}
if (ldo(lua_dostring, argv[i]) != 0) {
fprintf(stderr, "lua: error running argument `%.99s'\n", argv[i]);
return EXIT_FAILURE;
}
break;
}
case 'f': {
i++;
if (argv[i] == NULL) {
print_message();
return EXIT_FAILURE;
}
getargs(argv+i); /* collect remaining arguments */
lua_setglobal(L, "arg");
return file_input(argv[i]); /* stop scanning arguments */
}
case 's': {
fprintf(stderr, "lua: stack size (`-s') must be the first option\n");
return EXIT_FAILURE;
}
default: {
print_message();
return EXIT_FAILURE;
}
}
}
}
return EXIT_SUCCESS;
}
static void getstacksize (int argc, char *argv[], struct Options *opt) {
if (argc >= 2 && argv[1][0] == '-' && argv[1][1] == 's') {
int stacksize = atoi(&argv[1][2]);
if (stacksize <= 0) {
fprintf(stderr, "lua: invalid stack size ('%.20s')\n", &argv[1][2]);
exit(EXIT_FAILURE);
}
opt->stacksize = stacksize;
}
else
opt->stacksize = 0; /* no stack size */
}
static void register_getargs (char *argv[]) {
lua_pushuserdata(L, argv);
lua_pushcclosure(L, l_getargs, 1);
lua_setglobal(L, "getargs");
}
int main (int argc, char *argv[]) {
struct Options opt;
int status;
opt.toclose = 0;
getstacksize(argc, argv, &opt); /* handle option `-s' */
L = lua_open(opt.stacksize); /* create state */
userinit(); /* open libraries */
register_getargs(argv); /* create `getargs' function */
status = handle_argv(argv+1, &opt);
if (opt.toclose)
lua_close(L);
return status;
}