lua/lua.c
2002-07-10 17:49:01 -03:00

376 lines
8.6 KiB
C

/*
** $Id: lua.c,v 1.96 2002/07/10 20:44:34 roberto Exp roberto $
** 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 "lauxlib.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 PROMPT
#define PROMPT "> "
#endif
#ifndef PROMPT2
#define PROMPT2 ">> "
#endif
#ifndef LUA_USERINIT
#define LUA_USERINIT(L) openstdlibs(L)
#endif
static lua_State *L = NULL;
static const char *progname;
static lua_Hook old_hook = NULL;
static int old_mask = 0;
static void lstop (lua_State *l, lua_Debug *ar) {
(void)ar; /* unused arg. */
lua_sethook(l, old_hook, old_mask);
luaL_error(l, "interrupted!");
}
static void laction (int i) {
signal(i, SIG_DFL); /* if another SIGINT happens before lstop,
terminate process (default action) */
old_hook = lua_gethook(L);
old_mask = lua_gethookmask(L);
lua_sethook(L, lstop, LUA_MASKCALL | LUA_MASKRET | LUA_MASKCOUNT(1));
}
static void print_usage (void) {
fprintf(stderr,
"usage: %s [options] [prog [args]].\n"
"Available options are:\n"
" - execute stdin as a file\n"
" -e stat execute string `stat'\n"
" -i enter interactive mode after executing `prog'\n"
" -l name execute file `name'\n"
" -v print 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", msg);
}
static void report (int status, int traceback) {
const char *msg;
if (status) {
if (status == LUA_ERRRUN) {
if (!traceback) lua_pop(L, 1); /* remove traceback */
else {
if (lua_isstring(L, -2) && lua_isstring(L, -1))
lua_concat(L, 2); /* concat error message and traceback */
else
lua_remove(L, -2); /* leave only traceback on stack */
}
}
msg = lua_tostring(L, -1);
if (msg == NULL) msg = "(no message)";
l_message(progname, msg);
lua_pop(L, 1);
}
}
static int lcall (int clear) {
int status;
int top = lua_gettop(L);
signal(SIGINT, laction);
status = lua_pcall(L, 0, LUA_MULTRET);
signal(SIGINT, SIG_DFL);
if (status == 0 && clear)
lua_settop(L, top); /* remove eventual results */
return status;
}
static int l_panic (lua_State *l) {
(void)l;
l_message(progname, "unable to recover; exiting\n");
return 0;
}
static void print_version (void) {
l_message(NULL, LUA_VERSION " " LUA_COPYRIGHT "\n");
}
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(1);
report(status, 1);
return 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));
}
#ifndef save_line
#define save_line(b) /* empty */
#endif
#ifndef read_line
#define read_line(p) readline(p)
/* maximum length of an input line */
#ifndef MAXINPUT
#define MAXINPUT 512
#endif
static int readline (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 {
size_t l = strlen(buffer);
if (l > 0 && buffer[l-1] == '\n')
buffer[l-1] = '\0'; /* remove eventual `\n' */
lua_pushstring(L, buffer);
return 1;
}
}
#endif
static const char *get_prompt (int firstline) {
const char *p = NULL;
lua_getglobal(L, firstline ? "_PROMPT" : "_PROMPT2");
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 (read_line(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? */
lua_pushliteral(L, "\n"); /* no; add line separator */
if (read_line(get_prompt(0)) == 0) /* no more input? */
return -1;
lua_concat(L, lua_gettop(L)); /* join lines and line separator */
}
save_line(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);
report(status, 0);
if (status == 0 && lua_gettop(L) > 0) { /* any result to print? */
lua_getglobal(L, "print");
lua_insert(L, 1);
lua_pcall(L, lua_gettop(L)-1, 0);
}
}
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 (isatty(0)) {
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 '-': { /* `--' */
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 EXIT_FAILURE;
}
if (dostring(chunk, "=<command line>") != 0)
return EXIT_FAILURE;
break;
}
case 'l': {
const char *filename = argv[i] + 2;
if (*filename == '\0') filename = argv[++i];
if (filename == NULL) {
print_usage();
return EXIT_FAILURE;
}
if (file_input(filename))
return EXIT_FAILURE; /* stop if file fails */
break;
}
case 'c': {
l_message(progname, "option `-c' is deprecated\n");
break;
}
case 's': {
l_message(progname, "option `-s' is deprecated\n");
break;
}
default: {
print_usage();
return EXIT_FAILURE;
}
}
} endloop:
if (argv[i] != NULL) {
const char *filename = argv[i];
getargs(argv, i); /* collect remaining arguments */
lua_setglobal(L, "arg");
return file_input(filename); /* stop scanning arguments */
}
}
return EXIT_SUCCESS;
}
static int openstdlibs (lua_State *l) {
return lua_baselibopen(l) +
lua_tablibopen(l) +
lua_iolibopen(l) +
lua_strlibopen(l) +
lua_mathlibopen(l) +
lua_dblibopen(l) +
/* add your libraries here */
0;
}
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");
}
int main (int argc, char *argv[]) {
int status;
int interactive = 0;
(void)argc; /* to avoid warnings */
progname = argv[0];
L = lua_open(); /* create state */
lua_atpanic(L, l_panic);
lua_pop(L, LUA_USERINIT(L)); /* open libraries, discard any results */
status = handle_luainit();
if (status != 0) return status;
status = handle_argv(argv, &interactive);
if (status == 0 && interactive) manual_input();
lua_close(L);
return status;
}