lua.c
上传用户:yisoukefu
上传日期:2020-08-09
资源大小:39506k
文件大小:10k
- /*
- ** $Id: lua.c,v 1.157 2005/12/29 16:23:32 roberto Exp $
- ** Lua stand-alone interpreter
- ** See Copyright Notice in lua.h
- */
- #include <signal.h>
- #include <stdio.h>
- #include <stdlib.h>
- #include <string.h>
- #define lua_c
- #include "lua.h"
- #include "lauxlib.h"
- #include "lualib.h"
- 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 (void) {
- fprintf(stderr,
- "usage: %s [options] [script [args]].n"
- "Available options are:n"
- " -e stat execute string " LUA_QL("stat") "n"
- " -l name require library " LUA_QL("name") "n"
- " -i enter interactive mode after executing " LUA_QL("script") "n"
- " -v show version informationn"
- " -- stop handling optionsn"
- " - execute stdin and stop handling optionsn"
- ,
- progname);
- fflush(stderr);
- }
- static void l_message (const char *pname, const char *msg) {
- if (pname) fprintf(stderr, "%s: ", pname);
- fprintf(stderr, "%sn", msg);
- fflush(stderr);
- }
- static int report (lua_State *L, int status) {
- if (status && !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);
- }
- return status;
- }
- static int traceback (lua_State *L) {
- lua_getfield(L, LUA_GLOBALSINDEX, "debug");
- if (!lua_istable(L, -1)) {
- lua_pop(L, 1);
- return 1;
- }
- lua_getfield(L, -1, "traceback");
- if (!lua_isfunction(L, -1)) {
- lua_pop(L, 2);
- return 1;
- }
- lua_pushvalue(L, 1); /* pass error message */
- lua_pushinteger(L, 2); /* skip this function and traceback */
- lua_call(L, 2, 1); /* call debug.traceback */
- return 1;
- }
- static int docall (lua_State *L, int narg, int clear) {
- 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 */
- signal(SIGINT, laction);
- status = lua_pcall(L, narg, (clear ? 0 : LUA_MULTRET), base);
- signal(SIGINT, SIG_DFL);
- lua_remove(L, base); /* remove traceback function */
- /* force a complete garbage collection in case of errors */
- if (status != 0) lua_gc(L, LUA_GCCOLLECT, 0);
- return status;
- }
- static void print_version (void) {
- l_message(NULL, LUA_VERSION " " LUA_COPYRIGHT);
- }
- 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) || docall(L, 0, 1);
- 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) || docall(L, 0, 1);
- return report(L, status);
- }
- static int dolibrary (lua_State *L, const char *name) {
- lua_getglobal(L, "require");
- lua_pushstring(L, name);
- return report(L, lua_pcall(L, 1, 0, 0));
- }
- static const char *get_prompt (lua_State *L, int firstline) {
- const char *p;
- lua_getfield(L, LUA_GLOBALSINDEX, firstline ? "_PROMPT" : "_PROMPT2");
- p = lua_tostring(L, -1);
- if (p == NULL) p = (firstline ? LUA_PROMPT : LUA_PROMPT2);
- lua_pop(L, 1); /* remove global */
- return p;
- }
- static int incomplete (lua_State *L, int status) {
- if (status == LUA_ERRSYNTAX) {
- size_t lmsg;
- const char *msg = lua_tolstring(L, -1, &lmsg);
- const char *tp = msg + lmsg - (sizeof(LUA_QL("<eof>")) - 1);
- if (strstr(msg, LUA_QL("<eof>")) == tp) {
- 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);
- if (lua_readline(L, b, prmt) == 0)
- return 0; /* no input */
- l = strlen(b);
- if (l > 0 && b[l-1] == 'n') /* line ends with newline? */
- b[l-1] = ' '; /* 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 */
- status = luaL_loadbuffer(L, lua_tostring(L, 1), lua_strlen(L, 1), "=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 == 0) status = docall(L, 0, 0);
- report(L, 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 " LUA_QL("print") " (%s)",
- lua_tostring(L, -1)));
- }
- }
- lua_settop(L, 0); /* clear stack */
- fputs("n", stdout);
- fflush(stdout);
- 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 == 0)
- status = docall(L, narg, 0);
- else
- lua_pop(L, narg);
- return report(L, status);
- }
- static int collectargs (char **argv, int *pi, int *pv, int *pe) {
- int i;
- for (i = 1; argv[i] != NULL; i++) {
- if (argv[i][0] != '-') /* not an option? */
- return i;
- switch (argv[i][1]) { /* option */
- case '-': return (argv[i+1] != NULL ? i+1 : 0);
- case ' ': return i;
- case 'i': *pi = 1; /* go through */
- case 'v': *pv = 1; break;
- case 'e': *pe = 1; /* go through */
- case 'l':
- if (argv[i][2] == ' ') {
- i++;
- if (argv[i] == NULL) return -1;
- }
- break;
- default: return -1; /* invalid option */
- }
- }
- return 0;
- }
- static int runargs (lua_State *L, char **argv, int n) {
- int i;
- for (i = 1; i < n; i++) {
- if (argv[i] == NULL) continue;
- lua_assert(argv[i][0] == '-');
- switch (argv[i][1]) { /* option */
- case 'e': {
- const char *chunk = argv[i] + 2;
- if (*chunk == ' ') chunk = argv[++i];
- lua_assert(chunk != NULL);
- if (dostring(L, chunk, "=(command line)") != 0)
- return 1;
- break;
- }
- case 'l': {
- const char *filename = argv[i] + 2;
- if (*filename == ' ') filename = argv[++i];
- lua_assert(filename != NULL);
- if (dolibrary(L, filename))
- return 1; /* stop if file fails */
- break;
- }
- default: break;
- }
- }
- return 0;
- }
- static int handle_luainit (lua_State *L) {
- const char *init = getenv("LUA_INIT");
- if (init == NULL) return 0; /* status OK */
- else if (init[0] == '@')
- return dofile(L, init+1);
- else
- return dostring(L, 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);
- char **argv = s->argv;
- int script;
- int has_i = 0, has_v = 0, has_e = 0;
- globalL = L;
- if (argv[0] && argv[0][0]) progname = argv[0];
- lua_gc(L, LUA_GCSTOP, 0); /* stop collector during initialization */
- luaL_openlibs(L); /* open libraries */
- lua_gc(L, LUA_GCRESTART, 0);
- s->status = handle_luainit(L);
- if (s->status != 0) return 0;
- script = collectargs(argv, &has_i, &has_v, &has_e);
- if (script < 0) { /* invalid args? */
- print_usage();
- s->status = 1;
- return 0;
- }
- if (has_v) print_version();
- s->status = runargs(L, argv, (script > 0) ? script : s->argc);
- if (s->status != 0) return 0;
- if (script)
- s->status = handle_script(L, argv, script);
- if (s->status != 0) return 0;
- if (has_i)
- dotty(L);
- else if (script == 0 && !has_e && !has_v) {
- if (lua_stdin_is_tty()) {
- print_version();
- dotty(L);
- }
- else dofile(L, NULL); /* executes stdin as a file */
- }
- 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(L, status);
- lua_close(L);
- return (status || s.status) ? EXIT_FAILURE : EXIT_SUCCESS;
- }