/* ** $Id: lua.c,v 1.160.1.2 2007/12/28 15:32:23 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 information\n" " -- stop handling options\n" " - execute stdin and stop handling options\n" , progname); fflush(stderr); } static void l_message (const char *pname, const char *msg) { if (pname) fprintf(stderr, "%s: ", pname); fprintf(stderr, "%s\n", 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) { if (!lua_isstring(L, 1)) /* 'message' not a string? */ return 1; /* keep it intact */ 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_RELEASE " " 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, docall(L, 1, 1)); } 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] = '\0'; /* 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); } /* check that argument has no extra characters at the end */ #define notail(x) {if ((x)[2] != '\0') return -1;} 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 '-': notail(argv[i]); return (argv[i+1] != NULL ? i+1 : 0); case '\0': return i; case 'i': notail(argv[i]); *pi = 1; /* go through */ case 'v': notail(argv[i]); *pv = 1; break; case 'e': *pe = 1; /* go through */ case 'l': if (argv[i][2] == '\0') { 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 == '\0') 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 == '\0') 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; }