lua/lua.c

348 lines
8.3 KiB
C

/*
** $Id: lua.c,v 1.70 2001/09/25 17:06:34 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_PRIVATE
#include "lua.h"
#include "luadebug.h"
#include "lualib.h"
#ifdef _POSIX_SOURCE
#include <unistd.h>
#else
static int isatty (int x) { return x==0; } /* assume stdin is a tty */
#endif
#ifndef LUA_PROGNAME
#define LUA_PROGNAME l_s("lua: ")
#endif
#ifndef PROMPT
#define PROMPT l_s("> ")
#endif
#ifndef LUA_USERINIT
#define LUA_USERINIT(L) openstdlibs(L)
#endif
static lua_State *L = NULL;
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 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, l_s("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 l_char *), const l_char *name,
int clear) {
int res;
handler h = lreset();
int top = lua_gettop(L);
res = f(L, name); /* dostring | dofile */
if (clear)
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_PROGNAME l_s("memory allocation error\n"));
}
else if (res == LUA_ERRERR)
fprintf(stderr, LUA_PROGNAME l_s("error in error message\n"));
return res;
}
static void print_message (void) {
fprintf(stderr,
l_s("usage: lua [options]. Available options are:\n")
l_s(" - execute stdin as a file\n")
l_s(" -c close Lua when exiting\n")
l_s(" -e stat execute string `stat'\n")
l_s(" -f name execute file `name' with remaining arguments in table `arg'\n")
l_s(" -i enter interactive mode with prompt\n")
l_s(" -q enter interactive mode without prompt\n")
l_s(" -sNUM set stack size to NUM (must be the first option)\n")
l_s(" -v print version information\n")
l_s(" a=b set global `a' to string `b'\n")
l_s(" name execute file `name'\n")
);
}
static void print_version (void) {
printf(l_s("%.80s %.80s\n"), l_s(LUA_VERSION), l_s(LUA_COPYRIGHT));
}
static void assign (l_char *arg) {
l_char *eq = strchr(arg, l_c('='));
*eq = l_c('\0'); /* spilt `arg' in two strings (name & value) */
lua_pushstring(L, eq+1);
lua_setglobal(L, arg);
}
static void getargs (l_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_pushliteral(L, l_s("n"));
lua_pushnumber(L, i-1);
lua_settable(L, -3);
}
static int l_getargs (lua_State *l) {
l_char **argv = (l_char **)lua_touserdata(l, lua_upvalueindex(1));
getargs(argv);
return 1;
}
static int file_input (const l_char *argv) {
int result = ldo(lua_dofile, argv, 1);
if (result) {
if (result == LUA_ERRFILE) {
fprintf(stderr, LUA_PROGNAME l_s("cannot execute file "));
perror(argv);
}
return EXIT_FAILURE;
}
else
return EXIT_SUCCESS;
}
/* maximum length of an input line */
#ifndef MAXINPUT
#define MAXINPUT 512
#endif
static const l_char *get_prompt (int prompt) {
if (!prompt)
return l_s("");
else {
const l_char *s;
lua_getglobal(L, l_s("_PROMPT"));
s = lua_tostring(L, -1);
if (!s) s = PROMPT;
lua_pop(L, 1); /* remove global */
return s;
}
}
static void manual_input (int version, int prompt) {
if (version) print_version();
for (;;) {
int firstline = 1;
int toprint = 0;
fputs(get_prompt(prompt), stdout); /* show prompt */
for(;;) {
l_char buffer[MAXINPUT];
size_t l;
if (fgets(buffer, sizeof(buffer), stdin) == NULL) {
printf(l_s("\n"));
return;
}
if (firstline && buffer[0] == l_c('=')) {
buffer[0] = l_c(' ');
lua_pushstring(L, l_s("return"));
toprint = 1;
}
l = strlen(buffer);
if (buffer[l-1] == l_c('\n') && buffer[l-2] == l_c('\\')) {
buffer[l-2] = l_c('\n');
lua_pushlstring(L, buffer, l-1);
}
else {
lua_pushlstring(L, buffer, l);
break;
}
firstline = 0;
}
lua_concat(L, lua_gettop(L));
ldo(lua_dostring, lua_tostring(L, 1), 0);
lua_remove(L, 1); /* remove ran string */
if (toprint && lua_gettop(L) > 0) { /* any result to print? */
lua_getglobal(L, l_s("print"));
lua_insert(L, 1);
lua_call(L, lua_gettop(L)-1, 0);
}
else
lua_settop(L, 0); /* remove eventual results */
}
}
static int handle_argv (l_char *argv[], int *toclose) {
if (*argv == NULL) { /* no more arguments? */
if (isatty(0)) {
manual_input(1, 1);
}
else
ldo(lua_dofile, NULL, 1); /* executes stdin as a file */
}
else { /* other arguments; loop over them */
int i;
for (i = 0; argv[i] != NULL; i++) {
if (argv[i][0] != l_c('-')) { /* not an option? */
if (strchr(argv[i], l_c('=')))
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, 1); /* executes stdin as a file */
break;
}
case l_c('i'): {
manual_input(0, 1);
break;
}
case l_c('q'): {
manual_input(0, 0);
break;
}
case l_c('c'): {
*toclose = 1;
break;
}
case l_c('v'): {
print_version();
break;
}
case l_c('e'): {
i++;
if (argv[i] == NULL) {
print_message();
return EXIT_FAILURE;
}
if (ldo(lua_dostring, argv[i], 1) != 0) {
fprintf(stderr, LUA_PROGNAME l_s("error running argument `%.99s'\n"),
argv[i]);
return EXIT_FAILURE;
}
break;
}
case l_c('f'): {
i++;
if (argv[i] == NULL) {
print_message();
return EXIT_FAILURE;
}
getargs(argv+i); /* collect remaining arguments */
lua_setglobal(L, l_s("arg"));
return file_input(argv[i]); /* stop scanning arguments */
}
case l_c('s'): {
if (i == 0) break; /* option already handled */
fprintf(stderr,
LUA_PROGNAME l_s("stack size (`-s') must be the first option\n"));
return EXIT_FAILURE;
}
default: {
print_message();
return EXIT_FAILURE;
}
}
}
}
return EXIT_SUCCESS;
}
static int getstacksize (int argc, l_char *argv[]) {
int stacksize = 0;
if (argc >= 2 && argv[1][0] == l_c('-') && argv[1][1] == l_c('s')) {
stacksize = strtol(&argv[1][2], NULL, 10);
if (stacksize <= 0) {
fprintf(stderr, LUA_PROGNAME l_s("invalid stack size ('%.20s')\n"),
&argv[1][2]);
exit(EXIT_FAILURE);
}
}
return stacksize;
}
static void register_getargs (l_char *argv[]) {
lua_newuserdatabox(L, argv);
lua_pushcclosure(L, l_getargs, 1);
lua_setglobal(L, l_s("getargs"));
}
static void openstdlibs (lua_State *l) {
lua_baselibopen(l);
lua_iolibopen(l);
lua_strlibopen(l);
lua_mathlibopen(l);
lua_dblibopen(l);
}
int main (int argc, l_char *argv[]) {
int status;
int toclose = 0;
L = lua_open(getstacksize(argc, argv)); /* create state */
LUA_USERINIT(L); /* open libraries */
register_getargs(argv); /* create `getargs' function */
status = handle_argv(argv+1, &toclose);
if (toclose)
lua_close(L);
return status;
}