liolib.c
(5.2.4)
/*
** $Id: liolib.c,v 2.112.1.1 2013/04/12 18:48:47 roberto Exp $
** Standard I/O (and system) library
** See Copyright Notice in lua.h
*/
/*
** This definition must come before the inclusion of 'stdio.h'; it
** should not affect non-POSIX systems
*/
#if !defined(_FILE_OFFSET_BITS)
#define _LARGEFILE_SOURCE 1
#define _FILE_OFFSET_BITS 64
#endif
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define liolib_c
#define LUA_LIB
#include "lua.h"
#include "lauxlib.h"
#include "lualib.h"
#if !defined(lua_checkmode)
/*
** Check whether 'mode' matches '[rwa]%+?b?'.
** Change this macro to accept other modes for 'fopen' besides
** the standard ones.
*/
#define lua_checkmode(mode) \
(*mode != '\0' && strchr("rwa", *(mode++)) != NULL && \
(*mode != '+' || ++mode) && /* skip if char is '+' */ \
(*mode != 'b' || ++mode) && /* skip if char is 'b' */ \
(*mode == '\0'))
#endif
/*
** {======================================================
** lua_popen spawns a new process connected to the current
** one through the file streams.
** =======================================================
*/
#if !defined(lua_popen) /* { */
#if defined(LUA_USE_POPEN) /* { */
#define lua_popen(L,c,m) ((void)L, fflush(NULL), popen(c,m))
#define lua_pclose(L,file) ((void)L, pclose(file))
#elif defined(LUA_WIN) /* }{ */
#define lua_popen(L,c,m) ((void)L, _popen(c,m))
#define lua_pclose(L,file) ((void)L, _pclose(file))
#else /* }{ */
#define lua_popen(L,c,m) ((void)((void)c, m), \
luaL_error(L, LUA_QL("popen") " not supported"), (FILE*)0)
#define lua_pclose(L,file) ((void)((void)L, file), -1)
#endif /* } */
#endif /* } */
/* }====================================================== */
/*
** {======================================================
** lua_fseek: configuration for longer offsets
** =======================================================
*/
#if !defined(lua_fseek) && !defined(LUA_ANSI) /* { */
#if defined(LUA_USE_POSIX) /* { */
#define l_fseek(f,o,w) fseeko(f,o,w)
#define l_ftell(f) ftello(f)
#define l_seeknum off_t
#elif defined(LUA_WIN) && !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
#endif /* } */
#endif /* } */
#if !defined(l_fseek) /* default definitions */
#define l_fseek(f,o,w) fseek(f,o,w)
#define l_ftell(f) ftell(f)
#define l_seeknum long
#endif
/* }====================================================== */
#define IO_PREFIX "_IO_"
#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
** file is not left opened.
*/
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;
}
static int aux_close (lua_State *L) {
LStream *p = tolstream(L);
lua_CFunction cf = p->closef;
p->closef = NULL; /* mark stream as closed */
return (*cf)(L); /* close it */
}
static int io_close (lua_State *L) {
if (lua_isnone(L, 1)) /* no argument? */
lua_getfield(L, LUA_REGISTRYINDEX, IO_OUTPUT); /* use standard output */
tofile(L); /* make sure argument is an open stream */
return aux_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 " LUA_QS " (%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, lua_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, lua_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 = lua_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 + strlen(IO_PREFIX));
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);
static void aux_lines (lua_State *L, int toclose) {
int i;
int n = lua_gettop(L) - 1; /* number of arguments to read */
/* ensure that arguments will fit here and into 'io_readline' stack */
luaL_argcheck(L, n <= LUA_MINSTACK - 3, LUA_MINSTACK - 3, "too many options");
lua_pushvalue(L, 1); /* file handle */
lua_pushinteger(L, n); /* number of arguments to read */
lua_pushboolean(L, toclose); /* close/not close file when finished */
for (i = 1; i <= n; i++) lua_pushvalue(L, i + 1); /* copy arguments */
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
** =======================================================
*/
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, int chop) {
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_rawlen(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 - chop); /* chop 'eol' if needed */
luaL_pushresult(&b); /* close buffer */
return 1; /* read at least an `eol' */
}
}
}
#define MAX_SIZE_T (~(size_t)0)
static void read_all (lua_State *L, FILE *f) {
size_t rlen = LUAL_BUFFERSIZE; /* how much to read in each cycle */
luaL_Buffer b;
luaL_buffinit(L, &b);
for (;;) {
char *p = luaL_prepbuffsize(&b, rlen);
size_t nr = fread(p, sizeof(char), rlen, f);
luaL_addsize(&b, nr);
if (nr < rlen) break; /* eof? */
else if (rlen <= (MAX_SIZE_T / 4)) /* avoid buffers too large */
rlen *= 2; /* double buffer size at each iteration */
}
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)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, 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);
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_isnil(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 */
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);
}
}
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_Number p3 = luaL_optnumber(L, 3, 0);
l_seeknum offset = (l_seeknum)p3;
luaL_argcheck(L, (lua_Number)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_pushnumber(L, (lua_Number)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 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", io_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;
}