liolib.c
(5.4.7)
/*
** $Id: liolib.c $
** 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 != '+' || ((void)(++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))
#if !defined(l_checkmodep)
/* Windows accepts "[rw][bt]?" as valid modes */
#define l_checkmodep(m) ((m[0] == 'r' || m[0] == 'w') && \
(m[1] == '\0' || ((m[1] == 'b' || m[1] == 't') && m[2] == '\0')))
#endif
#else /* }{ */
/* ISO C definitions */
#define l_popen(L,c,m) \
((void)c, (void)m, \
luaL_error(L, "'popen' not supported"), \
(FILE*)0)
#define l_pclose(L,file) ((void)L, (void)file, -1)
#endif /* } */
#endif /* } */
#if !defined(l_checkmodep)
/* By default, Lua accepts only "r" or "w" as valid modes */
#define l_checkmodep(m) ((m[0] == 'r' || m[0] == 'w') && m[1] == '\0')
#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)
luaL_pushfail(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 (l_unlikely(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_newuserdatauv(L, sizeof(LStream), 0);
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 default 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);
errno = 0;
return luaL_fileresult(L, (fclose(p->f) == 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 (l_unlikely(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");
errno = 0;
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);
errno = 0;
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);
luaL_argcheck(L, l_checkmodep(mode), 2, "invalid mode");
errno = 0;
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);
errno = 0;
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 (l_unlikely(isclosed(p)))
luaL_error(L, "default %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
/*
** Auxiliary function to create the iteration function for 'lines'.
** The iteration function is a closure over 'io_readline', with
** the following upvalues:
** 1) The file being read (first value in the stack)
** 2) the number of arguments to read
** 3) a boolean, true iff file has to be closed when finished ('toclose')
** *) a variable number of format arguments (rest of the stack)
*/
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_pushvalue(L, 1); /* file */
lua_pushinteger(L, n); /* number of arguments to read */
lua_pushboolean(L, toclose); /* close/not close file when finished */
lua_rotate(L, 2, 3); /* move the three values 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;
}
/*
** Return an iteration function for 'io.lines'. If file has to be
** closed, also returns the file itself as a second result (to be
** closed as the state at the exit of a generic for).
*/
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); /* push iteration function */
if (toclose) {
lua_pushnil(L); /* state */
lua_pushnil(L); /* control */
lua_pushvalue(L, 1); /* file is the to-be-closed variable (4th result) */
return 4;
}
else
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 (l_unlikely(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 sign */
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 sign */
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 (l_likely(lua_stringtonumber(L, rn.buff)))
return 1; /* ok, it is a valid number */
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;
luaL_buffinit(L, &b);
do { /* may need to read several chunks to get whole line */
char *buff = luaL_prepbuffer(&b); /* preallocate buffer space */
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; /* read up to end of line or buffer limit */
l_unlockfile(f);
luaL_addsize(&b, i);
} while (c != EOF && c != '\n'); /* repeat until end of line */
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 n, success;
clearerr(f);
errno = 0;
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 */
luaL_pushfail(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);
}
/*
** Iteration function for 'lines'.
*/
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 false: 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); /* clear stack */
lua_pushvalue(L, lua_upvalueindex(1)); /* push file at index 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;
errno = 0;
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 (l_likely(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");
errno = 0;
op = l_fseek(f, offset, mode[op]);
if (l_unlikely(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;
errno = 0;
res = setvbuf(f, NULL, mode[op], (size_t)sz);
return luaL_fileresult(L, res == 0, NULL);
}
static int io_flush (lua_State *L) {
FILE *f = getiofile(L, IO_OUTPUT);
errno = 0;
return luaL_fileresult(L, fflush(f) == 0, NULL);
}
static int f_flush (lua_State *L) {
FILE *f = tofile(L);
errno = 0;
return luaL_fileresult(L, fflush(f) == 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 meth[] = {
{"read", f_read},
{"write", f_write},
{"lines", f_lines},
{"flush", f_flush},
{"seek", f_seek},
{"close", f_close},
{"setvbuf", f_setvbuf},
{NULL, NULL}
};
/*
** metamethods for file handles
*/
static const luaL_Reg metameth[] = {
{"__index", NULL}, /* placeholder */
{"__gc", f_gc},
{"__close", f_gc},
{"__tostring", f_tostring},
{NULL, NULL}
};
static void createmeta (lua_State *L) {
luaL_newmetatable(L, LUA_FILEHANDLE); /* metatable for file handles */
luaL_setfuncs(L, metameth, 0); /* add metamethods to new metatable */
luaL_newlibtable(L, meth); /* create method table */
luaL_setfuncs(L, meth, 0); /* add file methods to method table */
lua_setfield(L, -2, "__index"); /* metatable.__index = method table */
lua_pop(L, 1); /* pop 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 */
luaL_pushfail(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;
}