/* ** $Id: liolib.c,v 2.73.1.3 2008/01/18 17:47:43 roberto Exp $ ** Standard I/O (and system) library ** See Copyright Notice in lua.h */ #include #include #include #include #define liolib_c #define LUA_LIB #include "lua.h" #include "lauxlib.h" #include "lualib.h" #define IO_INPUT 1 #define IO_OUTPUT 2 static const char *const fnames[] = {"input", "output"}; static int pushresult (lua_State *L, int i, const char *filename) { int en = errno; /* calls to Lua API may change this value */ if (i) { lua_pushboolean(L, 1); return 1; } else { lua_pushnil(L); if (filename) lua_pushfstring(L, "%s: %s", filename, strerror(en)); else lua_pushfstring(L, "%s", strerror(en)); lua_pushinteger(L, en); return 3; } } static void fileerror (lua_State *L, int arg, const char *filename) { lua_pushfstring(L, "%s: %s", filename, strerror(errno)); luaL_argerror(L, arg, lua_tostring(L, -1)); } #define tofilep(L) ((FILE **)luaL_checkudata(L, 1, LUA_FILEHANDLE)) static int io_type (lua_State *L) { void *ud; luaL_checkany(L, 1); ud = lua_touserdata(L, 1); lua_getfield(L, LUA_REGISTRYINDEX, LUA_FILEHANDLE); if (ud == NULL || !lua_getmetatable(L, 1) || !lua_rawequal(L, -2, -1)) lua_pushnil(L); /* not a file */ else if (*((FILE **)ud) == NULL) lua_pushliteral(L, "closed file"); else lua_pushliteral(L, "file"); return 1; } static FILE *tofile (lua_State *L) { FILE **f = tofilep(L); if (*f == NULL) luaL_error(L, "attempt to use a closed file"); return *f; } /* ** When creating file handles, always creates a `closed' file handle ** before opening the actual file; so, if there is a memory error, the ** file is not left opened. */ static FILE **newfile (lua_State *L) { FILE **pf = (FILE **)lua_newuserdata(L, sizeof(FILE *)); *pf = NULL; /* file handle is currently `closed' */ luaL_getmetatable(L, LUA_FILEHANDLE); lua_setmetatable(L, -2); return pf; } /* ** function to (not) close the standard files stdin, stdout, and stderr */ static int io_noclose (lua_State *L) { lua_pushnil(L); lua_pushliteral(L, "cannot close standard file"); return 2; } /* ** function to close 'popen' files */ static int io_pclose (lua_State *L) { FILE **p = tofilep(L); int ok = lua_pclose(L, *p); *p = NULL; return pushresult(L, ok, NULL); } /* ** function to close regular files */ static int io_fclose (lua_State *L) { FILE **p = tofilep(L); int ok = (fclose(*p) == 0); *p = NULL; return pushresult(L, ok, NULL); } static int aux_close (lua_State *L) { lua_getfenv(L, 1); lua_getfield(L, -1, "__close"); return (lua_tocfunction(L, -1))(L); } static int io_close (lua_State *L) { if (lua_isnone(L, 1)) lua_rawgeti(L, LUA_ENVIRONINDEX, IO_OUTPUT); tofile(L); /* make sure argument is a file */ return aux_close(L); } static int io_gc (lua_State *L) { FILE *f = *tofilep(L); /* ignore closed files */ if (f != NULL) aux_close(L); return 0; } static int io_tostring (lua_State *L) { FILE *f = *tofilep(L); if (f == NULL) lua_pushliteral(L, "file (closed)"); else lua_pushfstring(L, "file (%p)", f); return 1; } static int io_open (lua_State *L) { const char *filename = luaL_checkstring(L, 1); const char *mode = luaL_optstring(L, 2, "r"); FILE **pf = newfile(L); *pf = fopen(filename, mode); return (*pf == NULL) ? pushresult(L, 0, filename) : 1; } /* ** this function has a separated environment, which defines the ** correct __close for 'popen' files */ static int io_popen (lua_State *L) { const char *filename = luaL_checkstring(L, 1); const char *mode = luaL_optstring(L, 2, "r"); FILE **pf = newfile(L); *pf = lua_popen(L, filename, mode); return (*pf == NULL) ? pushresult(L, 0, filename) : 1; } static int io_tmpfile (lua_State *L) { FILE **pf = newfile(L); *pf = tmpfile(); return (*pf == NULL) ? pushresult(L, 0, NULL) : 1; } static FILE *getiofile (lua_State *L, int findex) { FILE *f; lua_rawgeti(L, LUA_ENVIRONINDEX, findex); f = *(FILE **)lua_touserdata(L, -1); if (f == NULL) luaL_error(L, "standard %s file is closed", fnames[findex - 1]); return f; } static int g_iofile (lua_State *L, int f, const char *mode) { if (!lua_isnoneornil(L, 1)) { const char *filename = lua_tostring(L, 1); if (filename) { FILE **pf = newfile(L); *pf = fopen(filename, mode); if (*pf == NULL) fileerror(L, 1, filename); } else { tofile(L); /* check that it's a valid file handle */ lua_pushvalue(L, 1); } lua_rawseti(L, LUA_ENVIRONINDEX, f); } /* return current value */ lua_rawgeti(L, LUA_ENVIRONINDEX, f); return 1; } static int io_input (lua_State *L) { return g_iofile(L, IO_INPUT, "r"); } static int io_output (lua_State *L) { return g_iofile(L, IO_OUTPUT, "w"); } static int io_readline (lua_State *L); static void aux_lines (lua_State *L, int idx, int toclose) { lua_pushvalue(L, idx); lua_pushboolean(L, toclose); /* close/not close file when finished */ lua_pushcclosure(L, io_readline, 2); } static int f_lines (lua_State *L) { tofile(L); /* check that it's a valid file handle */ aux_lines(L, 1, 0); return 1; } static int io_lines (lua_State *L) { if (lua_isnoneornil(L, 1)) { /* no arguments? */ /* will iterate over default input */ lua_rawgeti(L, LUA_ENVIRONINDEX, IO_INPUT); return f_lines(L); } else { const char *filename = luaL_checkstring(L, 1); FILE **pf = newfile(L); *pf = fopen(filename, "r"); if (*pf == NULL) fileerror(L, 1, filename); aux_lines(L, lua_gettop(L), 1); return 1; } } /* ** {====================================================== ** READ ** ======================================================= */ static int read_number (lua_State *L, FILE *f) { lua_Number d; if (fscanf(f, LUA_NUMBER_SCAN, &d) == 1) { lua_pushnumber(L, d); return 1; } else { lua_pushnil(L); /* "result" to be removed */ return 0; /* read fails */ } } static int test_eof (lua_State *L, FILE *f) { int c = getc(f); ungetc(c, f); lua_pushlstring(L, NULL, 0); return (c != EOF); } static int read_line (lua_State *L, FILE *f) { luaL_Buffer b; luaL_buffinit(L, &b); for (;;) { size_t l; char *p = luaL_prepbuffer(&b); if (fgets(p, LUAL_BUFFERSIZE, f) == NULL) { /* eof? */ luaL_pushresult(&b); /* close buffer */ return (lua_objlen(L, -1) > 0); /* check whether read something */ } l = strlen(p); if (l == 0 || p[l-1] != '\n') luaL_addsize(&b, l); else { luaL_addsize(&b, l - 1); /* do not include `eol' */ luaL_pushresult(&b); /* close buffer */ return 1; /* read at least an `eol' */ } } } static int read_chars (lua_State *L, FILE *f, size_t n) { size_t rlen; /* how much to read */ size_t nr; /* number of chars actually read */ luaL_Buffer b; luaL_buffinit(L, &b); rlen = LUAL_BUFFERSIZE; /* try to read that much each time */ do { char *p = luaL_prepbuffer(&b); if (rlen > n) rlen = n; /* cannot read more than asked */ nr = fread(p, sizeof(char), rlen, f); luaL_addsize(&b, nr); n -= nr; /* still have to read `n' chars */ } while (n > 0 && nr == rlen); /* until end of count or eof */ luaL_pushresult(&b); /* close buffer */ return (n == 0 || lua_objlen(L, -1) > 0); } static int g_read (lua_State *L, FILE *f, int first) { int nargs = lua_gettop(L) - 1; int success; int n; clearerr(f); if (nargs == 0) { /* no arguments? */ success = read_line(L, f); n = first+1; /* to return 1 result */ } else { /* ensure stack space for all results and for auxlib's buffer */ luaL_checkstack(L, nargs+LUA_MINSTACK, "too many arguments"); success = 1; for (n = first; nargs-- && success; n++) { if (lua_type(L, n) == LUA_TNUMBER) { size_t l = (size_t)lua_tointeger(L, n); success = (l == 0) ? test_eof(L, f) : read_chars(L, f, l); } else { const char *p = lua_tostring(L, n); luaL_argcheck(L, p && p[0] == '*', n, "invalid option"); switch (p[1]) { case 'n': /* number */ success = read_number(L, f); break; case 'l': /* line */ success = read_line(L, f); break; case 'a': /* file */ read_chars(L, f, ~((size_t)0)); /* read MAX_SIZE_T chars */ success = 1; /* always success */ break; default: return luaL_argerror(L, n, "invalid format"); } } } } if (ferror(f)) return pushresult(L, 0, NULL); if (!success) { lua_pop(L, 1); /* remove last result */ lua_pushnil(L); /* push nil instead */ } return n - first; } static int io_read (lua_State *L) { return g_read(L, getiofile(L, IO_INPUT), 1); } static int f_read (lua_State *L) { return g_read(L, tofile(L), 2); } static int io_readline (lua_State *L) { FILE *f = *(FILE **)lua_touserdata(L, lua_upvalueindex(1)); int sucess; if (f == NULL) /* file is already closed? */ luaL_error(L, "file is already closed"); sucess = read_line(L, f); if (ferror(f)) return luaL_error(L, "%s", strerror(errno)); if (sucess) return 1; else { /* EOF */ if (lua_toboolean(L, lua_upvalueindex(2))) { /* generator created file? */ lua_settop(L, 0); lua_pushvalue(L, lua_upvalueindex(1)); aux_close(L); /* close it */ } return 0; } } /* }====================================================== */ static int g_write (lua_State *L, FILE *f, int arg) { int nargs = lua_gettop(L) - 1; int status = 1; for (; nargs--; arg++) { if (lua_type(L, arg) == LUA_TNUMBER) { /* optimization: could be done exactly as for strings */ status = status && fprintf(f, LUA_NUMBER_FMT, lua_tonumber(L, arg)) > 0; } else { size_t l; const char *s = luaL_checklstring(L, arg, &l); status = status && (fwrite(s, sizeof(char), l, f) == l); } } return pushresult(L, status, NULL); } static int io_write (lua_State *L) { return g_write(L, getiofile(L, IO_OUTPUT), 1); } static int f_write (lua_State *L) { return g_write(L, tofile(L), 2); } static int f_seek (lua_State *L) { static const int mode[] = {SEEK_SET, SEEK_CUR, SEEK_END}; static const char *const modenames[] = {"set", "cur", "end", NULL}; FILE *f = tofile(L); int op = luaL_checkoption(L, 2, "cur", modenames); long offset = luaL_optlong(L, 3, 0); op = fseek(f, offset, mode[op]); if (op) return pushresult(L, 0, NULL); /* error */ else { lua_pushinteger(L, ftell(f)); return 1; } } static int f_setvbuf (lua_State *L) { static const int mode[] = {_IONBF, _IOFBF, _IOLBF}; static const char *const modenames[] = {"no", "full", "line", NULL}; FILE *f = tofile(L); int op = luaL_checkoption(L, 2, NULL, modenames); lua_Integer sz = luaL_optinteger(L, 3, LUAL_BUFFERSIZE); int res = setvbuf(f, NULL, mode[op], sz); return pushresult(L, res == 0, NULL); } static int io_flush (lua_State *L) { return pushresult(L, fflush(getiofile(L, IO_OUTPUT)) == 0, NULL); } static int f_flush (lua_State *L) { return pushresult(L, fflush(tofile(L)) == 0, NULL); } static const luaL_Reg iolib[] = { {"close", io_close}, {"flush", io_flush}, {"input", io_input}, {"lines", io_lines}, {"open", io_open}, {"output", io_output}, {"popen", io_popen}, {"read", io_read}, {"tmpfile", io_tmpfile}, {"type", io_type}, {"write", io_write}, {NULL, NULL} }; static const luaL_Reg flib[] = { {"close", io_close}, {"flush", f_flush}, {"lines", f_lines}, {"read", f_read}, {"seek", f_seek}, {"setvbuf", f_setvbuf}, {"write", f_write}, {"__gc", io_gc}, {"__tostring", io_tostring}, {NULL, NULL} }; static void createmeta (lua_State *L) { luaL_newmetatable(L, LUA_FILEHANDLE); /* create metatable for file handles */ lua_pushvalue(L, -1); /* push metatable */ lua_setfield(L, -2, "__index"); /* metatable.__index = metatable */ luaL_register(L, NULL, flib); /* file methods */ } static void createstdfile (lua_State *L, FILE *f, int k, const char *fname) { *newfile(L) = f; if (k > 0) { lua_pushvalue(L, -1); lua_rawseti(L, LUA_ENVIRONINDEX, k); } lua_pushvalue(L, -2); /* copy environment */ lua_setfenv(L, -2); /* set it */ lua_setfield(L, -3, fname); } static void newfenv (lua_State *L, lua_CFunction cls) { lua_createtable(L, 0, 1); lua_pushcfunction(L, cls); lua_setfield(L, -2, "__close"); } LUALIB_API int luaopen_io (lua_State *L) { createmeta(L); /* create (private) environment (with fields IO_INPUT, IO_OUTPUT, __close) */ newfenv(L, io_fclose); lua_replace(L, LUA_ENVIRONINDEX); /* open library */ luaL_register(L, LUA_IOLIBNAME, iolib); /* create (and set) default files */ newfenv(L, io_noclose); /* close function for default files */ createstdfile(L, stdin, IO_INPUT, "stdin"); createstdfile(L, stdout, IO_OUTPUT, "stdout"); createstdfile(L, stderr, 0, "stderr"); lua_pop(L, 1); /* pop environment for default files */ lua_getfield(L, -1, "popen"); newfenv(L, io_pclose); /* create environment for 'popen' */ lua_setfenv(L, -2); /* set fenv for 'popen' */ lua_pop(L, 1); /* pop 'popen' */ return 1; }