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niceSOFT
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v5.2.2
lua.c
496 строк
14 KB
Roberto Ierusalimschy
pops the string from 'get_prompt' only after using it
30 сен 2012, 00:07
30 сен 2012, 00:07
ab7086e
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/* ** $Id: lua.c,v 1.205 2012/05/23 15:37:09 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> #define lua_c #include "lua.h" #include "lauxlib.h" #include "lualib.h" #if !defined(LUA_PROMPT) #define LUA_PROMPT "> " #define LUA_PROMPT2 ">> " #endif #if !defined(LUA_PROGNAME) #define LUA_PROGNAME "lua" #endif #if !defined(LUA_MAXINPUT) #define LUA_MAXINPUT 512 #endif #if !defined(LUA_INIT) #define LUA_INIT "LUA_INIT" #endif #define LUA_INITVERSION \ LUA_INIT "_" LUA_VERSION_MAJOR "_" LUA_VERSION_MINOR /* ** lua_stdin_is_tty detects whether the standard input is a 'tty' (that ** is, whether we're running lua interactively). */ #if defined(LUA_USE_ISATTY) #include <unistd.h> #define lua_stdin_is_tty() isatty(0) #elif defined(LUA_WIN) #include <io.h> #include <stdio.h> #define lua_stdin_is_tty() _isatty(_fileno(stdin)) #else #define lua_stdin_is_tty() 1 /* assume stdin is a tty */ #endif /* ** lua_readline defines how to show a prompt and then read a line from ** the standard input. ** lua_saveline defines how to "save" a read line in a "history". ** lua_freeline defines how to free a line read by lua_readline. */ #if defined(LUA_USE_READLINE) #include <stdio.h> #include <readline/readline.h> #include <readline/history.h> #define lua_readline(L,b,p) ((void)L, ((b)=readline(p)) != NULL) #define lua_saveline(L,idx) \ if (lua_rawlen(L,idx) > 0) /* non-empty line? */ \ add_history(lua_tostring(L, idx)); /* add it to history */ #define lua_freeline(L,b) ((void)L, free(b)) #elif !defined(lua_readline) #define lua_readline(L,b,p) \ ((void)L, fputs(p, stdout), fflush(stdout), /* show prompt */ \ fgets(b, LUA_MAXINPUT, stdin) != NULL) /* get line */ #define lua_saveline(L,idx) { (void)L; (void)idx; } #define lua_freeline(L,b) { (void)L; (void)b; } #endif 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 (const char *badoption) { luai_writestringerror("%s: ", progname); if (badoption[1] == 'e' || badoption[1] == 'l') luai_writestringerror("'%s' needs argument\n", badoption); else luai_writestringerror("unrecognized option '%s'\n", badoption); luai_writestringerror( "usage: %s [options] [script [args]]\n" "Available options are:\n" " -e stat execute string " LUA_QL("stat") "\n" " -i enter interactive mode after executing " LUA_QL("script") "\n" " -l name require library " LUA_QL("name") "\n" " -v show version information\n" " -E ignore environment variables\n" " -- stop handling options\n" " - stop handling options and execute stdin\n" , progname); } static void l_message (const char *pname, const char *msg) { if (pname) luai_writestringerror("%s: ", pname); luai_writestringerror("%s\n", msg); } static int report (lua_State *L, int status) { if (status != LUA_OK && !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); /* force a complete garbage collection in case of errors */ lua_gc(L, LUA_GCCOLLECT, 0); } return status; } /* the next function is called unprotected, so it must avoid errors */ static void finalreport (lua_State *L, int status) { if (status != LUA_OK) { const char *msg = (lua_type(L, -1) == LUA_TSTRING) ? lua_tostring(L, -1) : NULL; if (msg == NULL) msg = "(error object is not a string)"; l_message(progname, msg); lua_pop(L, 1); } } static int traceback (lua_State *L) { const char *msg = lua_tostring(L, 1); if (msg) luaL_traceback(L, L, msg, 1); else if (!lua_isnoneornil(L, 1)) { /* is there an error object? */ if (!luaL_callmeta(L, 1, "__tostring")) /* try its 'tostring' metamethod */ lua_pushliteral(L, "(no error message)"); } return 1; } static int docall (lua_State *L, int narg, int nres) { 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 */ globalL = L; /* to be available to 'laction' */ signal(SIGINT, laction); status = lua_pcall(L, narg, nres, base); signal(SIGINT, SIG_DFL); lua_remove(L, base); /* remove traceback function */ return status; } static void print_version (void) { luai_writestring(LUA_COPYRIGHT, strlen(LUA_COPYRIGHT)); luai_writeline(); } 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); if (status == LUA_OK) status = docall(L, 0, 0); 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); if (status == LUA_OK) status = docall(L, 0, 0); return report(L, status); } static int dolibrary (lua_State *L, const char *name) { int status; lua_getglobal(L, "require"); lua_pushstring(L, name); status = docall(L, 1, 1); /* call 'require(name)' */ if (status == LUA_OK) lua_setglobal(L, name); /* global[name] = require return */ return report(L, status); } static const char *get_prompt (lua_State *L, int firstline) { const char *p; lua_getglobal(L, firstline ? "_PROMPT" : "_PROMPT2"); p = lua_tostring(L, -1); if (p == NULL) p = (firstline ? LUA_PROMPT : LUA_PROMPT2); return p; } /* mark in error messages for incomplete statements */ #define EOFMARK "<eof>" #define marklen (sizeof(EOFMARK)/sizeof(char) - 1) static int incomplete (lua_State *L, int status) { if (status == LUA_ERRSYNTAX) { size_t lmsg; const char *msg = lua_tolstring(L, -1, &lmsg); if (lmsg >= marklen && strcmp(msg + lmsg - marklen, EOFMARK) == 0) { 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); int readstatus = lua_readline(L, b, prmt); lua_pop(L, 1); /* remove result from 'get_prompt' */ if (readstatus == 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 */ size_t l; const char *line = lua_tolstring(L, 1, &l); status = luaL_loadbuffer(L, line, l, "=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 == LUA_OK) status = docall(L, 0, LUA_MULTRET); report(L, status); if (status == LUA_OK && lua_gettop(L) > 0) { /* any result to print? */ luaL_checkstack(L, LUA_MINSTACK, "too many results to print"); lua_getglobal(L, "print"); lua_insert(L, 1); if (lua_pcall(L, lua_gettop(L)-1, 0, 0) != LUA_OK) l_message(progname, lua_pushfstring(L, "error calling " LUA_QL("print") " (%s)", lua_tostring(L, -1))); } } lua_settop(L, 0); /* clear stack */ luai_writeline(); 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 == LUA_OK) status = docall(L, narg, LUA_MULTRET); else lua_pop(L, narg); return report(L, status); } /* check that argument has no extra characters at the end */ #define noextrachars(x) {if ((x)[2] != '\0') return -1;} /* indices of various argument indicators in array args */ #define has_i 0 /* -i */ #define has_v 1 /* -v */ #define has_e 2 /* -e */ #define has_E 3 /* -E */ #define num_has 4 /* number of 'has_*' */ static int collectargs (char **argv, int *args) { int i; for (i = 1; argv[i] != NULL; i++) { if (argv[i][0] != '-') /* not an option? */ return i; switch (argv[i][1]) { /* option */ case '-': noextrachars(argv[i]); return (argv[i+1] != NULL ? i+1 : 0); case '\0': return i; case 'E': args[has_E] = 1; break; case 'i': noextrachars(argv[i]); args[has_i] = 1; /* go through */ case 'v': noextrachars(argv[i]); args[has_v] = 1; break; case 'e': args[has_e] = 1; /* go through */ case 'l': /* both options need an argument */ if (argv[i][2] == '\0') { /* no concatenated argument? */ i++; /* try next 'argv' */ if (argv[i] == NULL || argv[i][0] == '-') return -(i - 1); /* no next argument or it is another option */ } break; default: /* invalid option; return its index... */ return -i; /* ...as a negative value */ } } return 0; } static int runargs (lua_State *L, char **argv, int n) { int i; for (i = 1; i < n; i++) { 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)") != LUA_OK) return 0; break; } case 'l': { const char *filename = argv[i] + 2; if (*filename == '\0') filename = argv[++i]; lua_assert(filename != NULL); if (dolibrary(L, filename) != LUA_OK) return 0; /* stop if file fails */ break; } default: break; } } return 1; } static int handle_luainit (lua_State *L) { const char *name = "=" LUA_INITVERSION; const char *init = getenv(name + 1); if (init == NULL) { name = "=" LUA_INIT; init = getenv(name + 1); /* try alternative name */ } if (init == NULL) return LUA_OK; else if (init[0] == '@') return dofile(L, init+1); else return dostring(L, init, name); } static int pmain (lua_State *L) { int argc = (int)lua_tointeger(L, 1); char **argv = (char **)lua_touserdata(L, 2); int script; int args[num_has]; args[has_i] = args[has_v] = args[has_e] = args[has_E] = 0; if (argv[0] && argv[0][0]) progname = argv[0]; script = collectargs(argv, args); if (script < 0) { /* invalid arg? */ print_usage(argv[-script]); return 0; } if (args[has_v]) print_version(); if (args[has_E]) { /* option '-E'? */ lua_pushboolean(L, 1); /* signal for libraries to ignore env. vars. */ lua_setfield(L, LUA_REGISTRYINDEX, "LUA_NOENV"); } /* open standard libraries */ luaL_checkversion(L); lua_gc(L, LUA_GCSTOP, 0); /* stop collector during initialization */ luaL_openlibs(L); /* open libraries */ lua_gc(L, LUA_GCRESTART, 0); if (!args[has_E] && handle_luainit(L) != LUA_OK) return 0; /* error running LUA_INIT */ /* execute arguments -e and -l */ if (!runargs(L, argv, (script > 0) ? script : argc)) return 0; /* execute main script (if there is one) */ if (script && handle_script(L, argv, script) != LUA_OK) return 0; if (args[has_i]) /* -i option? */ dotty(L); else if (script == 0 && !args[has_e] && !args[has_v]) { /* no arguments? */ if (lua_stdin_is_tty()) { print_version(); dotty(L); } else dofile(L, NULL); /* executes stdin as a file */ } lua_pushboolean(L, 1); /* signal no errors */ return 1; } int main (int argc, char **argv) { int status, result; lua_State *L = luaL_newstate(); /* create state */ if (L == NULL) { l_message(argv[0], "cannot create state: not enough memory"); return EXIT_FAILURE; } /* call 'pmain' in protected mode */ lua_pushcfunction(L, &pmain); lua_pushinteger(L, argc); /* 1st argument */ lua_pushlightuserdata(L, argv); /* 2nd argument */ status = lua_pcall(L, 2, 1, 0); result = lua_toboolean(L, -1); /* get result */ finalreport(L, status); lua_close(L); return (result && status == LUA_OK) ? EXIT_SUCCESS : EXIT_FAILURE; }