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authorJeffrey Armstrong <jeff@approximatrix.com>2020-09-28 20:25:16 -0400
committerJeffrey Armstrong <jeff@approximatrix.com>2020-09-28 20:25:16 -0400
commit334ee3f66a7aad17c9865bd9952b0c501b97721a (patch)
tree0ee71269e8c482e6a2df9cbb37dbe15302136799 /src/liolib.c
downloadrainbow-lua-334ee3f66a7aad17c9865bd9952b0c501b97721a.zip
rainbow-lua-334ee3f66a7aad17c9865bd9952b0c501b97721a.tar.gz
Initial import based on Lua 5.3.5
Diffstat (limited to 'src/liolib.c')
-rw-r--r--src/liolib.c776
1 files changed, 776 insertions, 0 deletions
diff --git a/src/liolib.c b/src/liolib.c
new file mode 100644
index 0000000..8a9e75c
--- /dev/null
+++ b/src/liolib.c
@@ -0,0 +1,776 @@
+/*
+** $Id: liolib.c,v 2.151.1.1 2017/04/19 17:29:57 roberto Exp $
+** Standard I/O (and system) library
+** See Copyright Notice in lua.h
+*/
+
+#define liolib_c
+#define LUA_LIB
+
+#include "lprefix.h"
+
+
+#include <ctype.h>
+#include <errno.h>
+#include <locale.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "lua.h"
+
+#include "lauxlib.h"
+#include "lualib.h"
+
+
+
+
+/*
+** Change this macro to accept other modes for 'fopen' besides
+** the standard ones.
+*/
+#if !defined(l_checkmode)
+
+/* accepted extensions to 'mode' in 'fopen' */
+#if !defined(L_MODEEXT)
+#define L_MODEEXT "b"
+#endif
+
+/* Check whether 'mode' matches '[rwa]%+?[L_MODEEXT]*' */
+static int l_checkmode (const char *mode) {
+ return (*mode != '\0' && strchr("rwa", *(mode++)) != NULL &&
+ (*mode != '+' || (++mode, 1)) && /* skip if char is '+' */
+ (strspn(mode, L_MODEEXT) == strlen(mode))); /* check extensions */
+}
+
+#endif
+
+/*
+** {======================================================
+** l_popen spawns a new process connected to the current
+** one through the file streams.
+** =======================================================
+*/
+
+#if !defined(l_popen) /* { */
+
+#if defined(LUA_USE_POSIX) /* { */
+
+#define l_popen(L,c,m) (fflush(NULL), popen(c,m))
+#define l_pclose(L,file) (pclose(file))
+
+#elif defined(LUA_USE_WINDOWS) /* }{ */
+
+#define l_popen(L,c,m) (_popen(c,m))
+#define l_pclose(L,file) (_pclose(file))
+
+#else /* }{ */
+
+/* ISO C definitions */
+#define l_popen(L,c,m) \
+ ((void)((void)c, m), \
+ luaL_error(L, "'popen' not supported"), \
+ (FILE*)0)
+#define l_pclose(L,file) ((void)L, (void)file, -1)
+
+#endif /* } */
+
+#endif /* } */
+
+/* }====================================================== */
+
+
+#if !defined(l_getc) /* { */
+
+#if defined(LUA_USE_POSIX)
+#define l_getc(f) getc_unlocked(f)
+#define l_lockfile(f) flockfile(f)
+#define l_unlockfile(f) funlockfile(f)
+#else
+#define l_getc(f) getc(f)
+#define l_lockfile(f) ((void)0)
+#define l_unlockfile(f) ((void)0)
+#endif
+
+#endif /* } */
+
+
+/*
+** {======================================================
+** l_fseek: configuration for longer offsets
+** =======================================================
+*/
+
+#if !defined(l_fseek) /* { */
+
+#if defined(LUA_USE_POSIX) /* { */
+
+#include <sys/types.h>
+
+#define l_fseek(f,o,w) fseeko(f,o,w)
+#define l_ftell(f) ftello(f)
+#define l_seeknum off_t
+
+#elif defined(LUA_USE_WINDOWS) && !defined(_CRTIMP_TYPEINFO) \
+ && defined(_MSC_VER) && (_MSC_VER >= 1400) /* }{ */
+
+/* Windows (but not DDK) and Visual C++ 2005 or higher */
+#define l_fseek(f,o,w) _fseeki64(f,o,w)
+#define l_ftell(f) _ftelli64(f)
+#define l_seeknum __int64
+
+#else /* }{ */
+
+/* ISO C definitions */
+#define l_fseek(f,o,w) fseek(f,o,w)
+#define l_ftell(f) ftell(f)
+#define l_seeknum long
+
+#endif /* } */
+
+#endif /* } */
+
+/* }====================================================== */
+
+
+#define IO_PREFIX "_IO_"
+#define IOPREF_LEN (sizeof(IO_PREFIX)/sizeof(char) - 1)
+#define IO_INPUT (IO_PREFIX "input")
+#define IO_OUTPUT (IO_PREFIX "output")
+
+
+typedef luaL_Stream LStream;
+
+
+#define tolstream(L) ((LStream *)luaL_checkudata(L, 1, LUA_FILEHANDLE))
+
+#define isclosed(p) ((p)->closef == NULL)
+
+
+static int io_type (lua_State *L) {
+ LStream *p;
+ luaL_checkany(L, 1);
+ p = (LStream *)luaL_testudata(L, 1, LUA_FILEHANDLE);
+ if (p == NULL)
+ lua_pushnil(L); /* not a file */
+ else if (isclosed(p))
+ lua_pushliteral(L, "closed file");
+ else
+ lua_pushliteral(L, "file");
+ return 1;
+}
+
+
+static int f_tostring (lua_State *L) {
+ LStream *p = tolstream(L);
+ if (isclosed(p))
+ lua_pushliteral(L, "file (closed)");
+ else
+ lua_pushfstring(L, "file (%p)", p->f);
+ return 1;
+}
+
+
+static FILE *tofile (lua_State *L) {
+ LStream *p = tolstream(L);
+ if (isclosed(p))
+ luaL_error(L, "attempt to use a closed file");
+ lua_assert(p->f);
+ return p->f;
+}
+
+
+/*
+** When creating file handles, always creates a 'closed' file handle
+** before opening the actual file; so, if there is a memory error, the
+** handle is in a consistent state.
+*/
+static LStream *newprefile (lua_State *L) {
+ LStream *p = (LStream *)lua_newuserdata(L, sizeof(LStream));
+ p->closef = NULL; /* mark file handle as 'closed' */
+ luaL_setmetatable(L, LUA_FILEHANDLE);
+ return p;
+}
+
+
+/*
+** Calls the 'close' function from a file handle. The 'volatile' avoids
+** a bug in some versions of the Clang compiler (e.g., clang 3.0 for
+** 32 bits).
+*/
+static int aux_close (lua_State *L) {
+ LStream *p = tolstream(L);
+ volatile lua_CFunction cf = p->closef;
+ p->closef = NULL; /* mark stream as closed */
+ return (*cf)(L); /* close it */
+}
+
+
+static int f_close (lua_State *L) {
+ tofile(L); /* make sure argument is an open stream */
+ return aux_close(L);
+}
+
+
+static int io_close (lua_State *L) {
+ if (lua_isnone(L, 1)) /* no argument? */
+ lua_getfield(L, LUA_REGISTRYINDEX, IO_OUTPUT); /* use standard output */
+ return f_close(L);
+}
+
+
+static int f_gc (lua_State *L) {
+ LStream *p = tolstream(L);
+ if (!isclosed(p) && p->f != NULL)
+ aux_close(L); /* ignore closed and incompletely open files */
+ return 0;
+}
+
+
+/*
+** function to close regular files
+*/
+static int io_fclose (lua_State *L) {
+ LStream *p = tolstream(L);
+ int res = fclose(p->f);
+ return luaL_fileresult(L, (res == 0), NULL);
+}
+
+
+static LStream *newfile (lua_State *L) {
+ LStream *p = newprefile(L);
+ p->f = NULL;
+ p->closef = &io_fclose;
+ return p;
+}
+
+
+static void opencheck (lua_State *L, const char *fname, const char *mode) {
+ LStream *p = newfile(L);
+ p->f = fopen(fname, mode);
+ if (p->f == NULL)
+ luaL_error(L, "cannot open file '%s' (%s)", fname, strerror(errno));
+}
+
+
+static int io_open (lua_State *L) {
+ const char *filename = luaL_checkstring(L, 1);
+ const char *mode = luaL_optstring(L, 2, "r");
+ LStream *p = newfile(L);
+ const char *md = mode; /* to traverse/check mode */
+ luaL_argcheck(L, l_checkmode(md), 2, "invalid mode");
+ p->f = fopen(filename, mode);
+ return (p->f == NULL) ? luaL_fileresult(L, 0, filename) : 1;
+}
+
+
+/*
+** function to close 'popen' files
+*/
+static int io_pclose (lua_State *L) {
+ LStream *p = tolstream(L);
+ return luaL_execresult(L, l_pclose(L, p->f));
+}
+
+
+static int io_popen (lua_State *L) {
+ const char *filename = luaL_checkstring(L, 1);
+ const char *mode = luaL_optstring(L, 2, "r");
+ LStream *p = newprefile(L);
+ p->f = l_popen(L, filename, mode);
+ p->closef = &io_pclose;
+ return (p->f == NULL) ? luaL_fileresult(L, 0, filename) : 1;
+}
+
+
+static int io_tmpfile (lua_State *L) {
+ LStream *p = newfile(L);
+ p->f = tmpfile();
+ return (p->f == NULL) ? luaL_fileresult(L, 0, NULL) : 1;
+}
+
+
+static FILE *getiofile (lua_State *L, const char *findex) {
+ LStream *p;
+ lua_getfield(L, LUA_REGISTRYINDEX, findex);
+ p = (LStream *)lua_touserdata(L, -1);
+ if (isclosed(p))
+ luaL_error(L, "standard %s file is closed", findex + IOPREF_LEN);
+ return p->f;
+}
+
+
+static int g_iofile (lua_State *L, const char *f, const char *mode) {
+ if (!lua_isnoneornil(L, 1)) {
+ const char *filename = lua_tostring(L, 1);
+ if (filename)
+ opencheck(L, filename, mode);
+ else {
+ tofile(L); /* check that it's a valid file handle */
+ lua_pushvalue(L, 1);
+ }
+ lua_setfield(L, LUA_REGISTRYINDEX, f);
+ }
+ /* return current value */
+ lua_getfield(L, LUA_REGISTRYINDEX, 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);
+
+
+/*
+** maximum number of arguments to 'f:lines'/'io.lines' (it + 3 must fit
+** in the limit for upvalues of a closure)
+*/
+#define MAXARGLINE 250
+
+static void aux_lines (lua_State *L, int toclose) {
+ int n = lua_gettop(L) - 1; /* number of arguments to read */
+ luaL_argcheck(L, n <= MAXARGLINE, MAXARGLINE + 2, "too many arguments");
+ lua_pushinteger(L, n); /* number of arguments to read */
+ lua_pushboolean(L, toclose); /* close/not close file when finished */
+ lua_rotate(L, 2, 2); /* move 'n' and 'toclose' to their positions */
+ lua_pushcclosure(L, io_readline, 3 + n);
+}
+
+
+static int f_lines (lua_State *L) {
+ tofile(L); /* check that it's a valid file handle */
+ aux_lines(L, 0);
+ return 1;
+}
+
+
+static int io_lines (lua_State *L) {
+ int toclose;
+ if (lua_isnone(L, 1)) lua_pushnil(L); /* at least one argument */
+ if (lua_isnil(L, 1)) { /* no file name? */
+ lua_getfield(L, LUA_REGISTRYINDEX, IO_INPUT); /* get default input */
+ lua_replace(L, 1); /* put it at index 1 */
+ tofile(L); /* check that it's a valid file handle */
+ toclose = 0; /* do not close it after iteration */
+ }
+ else { /* open a new file */
+ const char *filename = luaL_checkstring(L, 1);
+ opencheck(L, filename, "r");
+ lua_replace(L, 1); /* put file at index 1 */
+ toclose = 1; /* close it after iteration */
+ }
+ aux_lines(L, toclose);
+ return 1;
+}
+
+
+/*
+** {======================================================
+** READ
+** =======================================================
+*/
+
+
+/* maximum length of a numeral */
+#if !defined (L_MAXLENNUM)
+#define L_MAXLENNUM 200
+#endif
+
+
+/* auxiliary structure used by 'read_number' */
+typedef struct {
+ FILE *f; /* file being read */
+ int c; /* current character (look ahead) */
+ int n; /* number of elements in buffer 'buff' */
+ char buff[L_MAXLENNUM + 1]; /* +1 for ending '\0' */
+} RN;
+
+
+/*
+** Add current char to buffer (if not out of space) and read next one
+*/
+static int nextc (RN *rn) {
+ if (rn->n >= L_MAXLENNUM) { /* buffer overflow? */
+ rn->buff[0] = '\0'; /* invalidate result */
+ return 0; /* fail */
+ }
+ else {
+ rn->buff[rn->n++] = rn->c; /* save current char */
+ rn->c = l_getc(rn->f); /* read next one */
+ return 1;
+ }
+}
+
+
+/*
+** Accept current char if it is in 'set' (of size 2)
+*/
+static int test2 (RN *rn, const char *set) {
+ if (rn->c == set[0] || rn->c == set[1])
+ return nextc(rn);
+ else return 0;
+}
+
+
+/*
+** Read a sequence of (hex)digits
+*/
+static int readdigits (RN *rn, int hex) {
+ int count = 0;
+ while ((hex ? isxdigit(rn->c) : isdigit(rn->c)) && nextc(rn))
+ count++;
+ return count;
+}
+
+
+/*
+** Read a number: first reads a valid prefix of a numeral into a buffer.
+** Then it calls 'lua_stringtonumber' to check whether the format is
+** correct and to convert it to a Lua number
+*/
+static int read_number (lua_State *L, FILE *f) {
+ RN rn;
+ int count = 0;
+ int hex = 0;
+ char decp[2];
+ rn.f = f; rn.n = 0;
+ decp[0] = lua_getlocaledecpoint(); /* get decimal point from locale */
+ decp[1] = '.'; /* always accept a dot */
+ l_lockfile(rn.f);
+ do { rn.c = l_getc(rn.f); } while (isspace(rn.c)); /* skip spaces */
+ test2(&rn, "-+"); /* optional signal */
+ if (test2(&rn, "00")) {
+ if (test2(&rn, "xX")) hex = 1; /* numeral is hexadecimal */
+ else count = 1; /* count initial '0' as a valid digit */
+ }
+ count += readdigits(&rn, hex); /* integral part */
+ if (test2(&rn, decp)) /* decimal point? */
+ count += readdigits(&rn, hex); /* fractional part */
+ if (count > 0 && test2(&rn, (hex ? "pP" : "eE"))) { /* exponent mark? */
+ test2(&rn, "-+"); /* exponent signal */
+ readdigits(&rn, 0); /* exponent digits */
+ }
+ ungetc(rn.c, rn.f); /* unread look-ahead char */
+ l_unlockfile(rn.f);
+ rn.buff[rn.n] = '\0'; /* finish string */
+ if (lua_stringtonumber(L, rn.buff)) /* is this a valid number? */
+ return 1; /* ok */
+ else { /* invalid format */
+ 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); /* no-op when c == EOF */
+ lua_pushliteral(L, "");
+ return (c != EOF);
+}
+
+
+static int read_line (lua_State *L, FILE *f, int chop) {
+ luaL_Buffer b;
+ int c = '\0';
+ luaL_buffinit(L, &b);
+ while (c != EOF && c != '\n') { /* repeat until end of line */
+ char *buff = luaL_prepbuffer(&b); /* preallocate buffer */
+ int i = 0;
+ l_lockfile(f); /* no memory errors can happen inside the lock */
+ while (i < LUAL_BUFFERSIZE && (c = l_getc(f)) != EOF && c != '\n')
+ buff[i++] = c;
+ l_unlockfile(f);
+ luaL_addsize(&b, i);
+ }
+ if (!chop && c == '\n') /* want a newline and have one? */
+ luaL_addchar(&b, c); /* add ending newline to result */
+ luaL_pushresult(&b); /* close buffer */
+ /* return ok if read something (either a newline or something else) */
+ return (c == '\n' || lua_rawlen(L, -1) > 0);
+}
+
+
+static void read_all (lua_State *L, FILE *f) {
+ size_t nr;
+ luaL_Buffer b;
+ luaL_buffinit(L, &b);
+ do { /* read file in chunks of LUAL_BUFFERSIZE bytes */
+ char *p = luaL_prepbuffer(&b);
+ nr = fread(p, sizeof(char), LUAL_BUFFERSIZE, f);
+ luaL_addsize(&b, nr);
+ } while (nr == LUAL_BUFFERSIZE);
+ luaL_pushresult(&b); /* close buffer */
+}
+
+
+static int read_chars (lua_State *L, FILE *f, size_t n) {
+ size_t nr; /* number of chars actually read */
+ char *p;
+ luaL_Buffer b;
+ luaL_buffinit(L, &b);
+ p = luaL_prepbuffsize(&b, n); /* prepare buffer to read whole block */
+ nr = fread(p, sizeof(char), n, f); /* try to read 'n' chars */
+ luaL_addsize(&b, nr);
+ luaL_pushresult(&b); /* close buffer */
+ return (nr > 0); /* true iff read something */
+}
+
+
+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, 1);
+ 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)luaL_checkinteger(L, n);
+ success = (l == 0) ? test_eof(L, f) : read_chars(L, f, l);
+ }
+ else {
+ const char *p = luaL_checkstring(L, n);
+ if (*p == '*') p++; /* skip optional '*' (for compatibility) */
+ switch (*p) {
+ case 'n': /* number */
+ success = read_number(L, f);
+ break;
+ case 'l': /* line */
+ success = read_line(L, f, 1);
+ break;
+ case 'L': /* line with end-of-line */
+ success = read_line(L, f, 0);
+ break;
+ case 'a': /* file */
+ read_all(L, f); /* read entire file */
+ success = 1; /* always success */
+ break;
+ default:
+ return luaL_argerror(L, n, "invalid format");
+ }
+ }
+ }
+ }
+ if (ferror(f))
+ return luaL_fileresult(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) {
+ LStream *p = (LStream *)lua_touserdata(L, lua_upvalueindex(1));
+ int i;
+ int n = (int)lua_tointeger(L, lua_upvalueindex(2));
+ if (isclosed(p)) /* file is already closed? */
+ return luaL_error(L, "file is already closed");
+ lua_settop(L , 1);
+ luaL_checkstack(L, n, "too many arguments");
+ for (i = 1; i <= n; i++) /* push arguments to 'g_read' */
+ lua_pushvalue(L, lua_upvalueindex(3 + i));
+ n = g_read(L, p->f, 2); /* 'n' is number of results */
+ lua_assert(n > 0); /* should return at least a nil */
+ if (lua_toboolean(L, -n)) /* read at least one value? */
+ return n; /* return them */
+ else { /* first result is nil: EOF or error */
+ if (n > 1) { /* is there error information? */
+ /* 2nd result is error message */
+ return luaL_error(L, "%s", lua_tostring(L, -n + 1));
+ }
+ if (lua_toboolean(L, lua_upvalueindex(3))) { /* 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) - arg;
+ int status = 1;
+ for (; nargs--; arg++) {
+ if (lua_type(L, arg) == LUA_TNUMBER) {
+ /* optimization: could be done exactly as for strings */
+ int len = lua_isinteger(L, arg)
+ ? fprintf(f, LUA_INTEGER_FMT,
+ (LUAI_UACINT)lua_tointeger(L, arg))
+ : fprintf(f, LUA_NUMBER_FMT,
+ (LUAI_UACNUMBER)lua_tonumber(L, arg));
+ status = status && (len > 0);
+ }
+ else {
+ size_t l;
+ const char *s = luaL_checklstring(L, arg, &l);
+ status = status && (fwrite(s, sizeof(char), l, f) == l);
+ }
+ }
+ if (status) return 1; /* file handle already on stack top */
+ else return luaL_fileresult(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) {
+ FILE *f = tofile(L);
+ lua_pushvalue(L, 1); /* push file at the stack top (to be returned) */
+ return g_write(L, f, 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);
+ lua_Integer p3 = luaL_optinteger(L, 3, 0);
+ l_seeknum offset = (l_seeknum)p3;
+ luaL_argcheck(L, (lua_Integer)offset == p3, 3,
+ "not an integer in proper range");
+ op = l_fseek(f, offset, mode[op]);
+ if (op)
+ return luaL_fileresult(L, 0, NULL); /* error */
+ else {
+ lua_pushinteger(L, (lua_Integer)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], (size_t)sz);
+ return luaL_fileresult(L, res == 0, NULL);
+}
+
+
+
+static int io_flush (lua_State *L) {
+ return luaL_fileresult(L, fflush(getiofile(L, IO_OUTPUT)) == 0, NULL);
+}
+
+
+static int f_flush (lua_State *L) {
+ return luaL_fileresult(L, fflush(tofile(L)) == 0, NULL);
+}
+
+
+/*
+** functions for 'io' library
+*/
+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}
+};
+
+
+/*
+** methods for file handles
+*/
+static const luaL_Reg flib[] = {
+ {"close", f_close},
+ {"flush", f_flush},
+ {"lines", f_lines},
+ {"read", f_read},
+ {"seek", f_seek},
+ {"setvbuf", f_setvbuf},
+ {"write", f_write},
+ {"__gc", f_gc},
+ {"__tostring", f_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_setfuncs(L, flib, 0); /* add file methods to new metatable */
+ lua_pop(L, 1); /* pop new metatable */
+}
+
+
+/*
+** function to (not) close the standard files stdin, stdout, and stderr
+*/
+static int io_noclose (lua_State *L) {
+ LStream *p = tolstream(L);
+ p->closef = &io_noclose; /* keep file opened */
+ lua_pushnil(L);
+ lua_pushliteral(L, "cannot close standard file");
+ return 2;
+}
+
+
+static void createstdfile (lua_State *L, FILE *f, const char *k,
+ const char *fname) {
+ LStream *p = newprefile(L);
+ p->f = f;
+ p->closef = &io_noclose;
+ if (k != NULL) {
+ lua_pushvalue(L, -1);
+ lua_setfield(L, LUA_REGISTRYINDEX, k); /* add file to registry */
+ }
+ lua_setfield(L, -2, fname); /* add file to module */
+}
+
+
+LUAMOD_API int luaopen_io (lua_State *L) {
+ luaL_newlib(L, iolib); /* new module */
+ createmeta(L);
+ /* create (and set) default files */
+ createstdfile(L, stdin, IO_INPUT, "stdin");
+ createstdfile(L, stdout, IO_OUTPUT, "stdout");
+ createstdfile(L, stderr, NULL, "stderr");
+ return 1;
+}
+