ref: 2c40ff2bbd0a9be161dd8032a40122a8f23cd27b
dir: /lua/src/liolib.c/
/*
** $Id: liolib.c,v 1.1 2006/12/23 01:55:12 rrt Exp $
** Standard I/O (and system) library
** See Copyright Notice in lua.h
*/
#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"
#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 topfile(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 = topfile(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;
}
/*
** this function has a separated environment, which defines the
** correct __close for 'popen' files
*/
static int io_pclose (lua_State *L) {
FILE **p = topfile(L);
int ok = lua_pclose(L, *p);
*p = NULL;
return pushresult(L, ok, NULL);
}
static int io_fclose (lua_State *L) {
FILE **p = topfile(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 = *topfile(L);
/* ignore closed files and standard files */
if (f != NULL && f != stdin && f != stdout && f != stderr)
aux_close(L);
return 0;
}
static int io_tostring (lua_State *L) {
FILE *f = *topfile(L);
if (f == NULL)
lua_pushstring(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;
}
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 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_strlen(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_strlen(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_setfield(L, -2, fname);
}
LUALIB_API int luaopen_io (lua_State *L) {
createmeta(L);
/* create (private) environment (with fields IO_INPUT, IO_OUTPUT, __close) */
lua_createtable(L, 2, 1);
lua_replace(L, LUA_ENVIRONINDEX);
/* open library */
luaL_register(L, LUA_IOLIBNAME, iolib);
/* create (and set) default files */
createstdfile(L, stdin, IO_INPUT, "stdin");
createstdfile(L, stdout, IO_OUTPUT, "stdout");
createstdfile(L, stderr, 0, "stderr");
/* create environment for 'popen' */
lua_getfield(L, -1, "popen");
lua_createtable(L, 0, 1);
lua_pushcfunction(L, io_pclose);
lua_setfield(L, -2, "__close");
lua_setfenv(L, -2);
lua_pop(L, 1); /* pop 'popen' */
/* set default close function */
lua_pushcfunction(L, io_fclose);
lua_setfield(L, LUA_ENVIRONINDEX, "__close");
return 1;
}