no more protected global variables; using upvalues to store tags.

This commit is contained in:
Roberto Ierusalimschy 1997-11-28 10:40:37 -02:00
parent a6ad644bf2
commit b42cc6a4d2
1 changed files with 48 additions and 35 deletions

View File

@ -1,5 +1,5 @@
/*
** $Id: liolib.c,v 1.6 1997/11/19 18:16:33 roberto Exp roberto $
** $Id: liolib.c,v 1.7 1997/11/27 15:59:44 roberto Exp roberto $
** Standard I/O (and system) library
** See Copyright Notice in lua.h
*/
@ -32,13 +32,16 @@
#endif
#define CLOSEDTAG ".CLOSEDTAG"
#define IOTAG ".IOTAG"
#define CLOSEDTAG 2
#define IOTAG 1
#define FINPUT "_INPUT"
#define FOUTPUT "_OUTPUT"
#define FIRSTARG 3 /* 1st and 2nd are upvalues */
#ifdef POPEN
FILE *popen();
int pclose();
@ -48,16 +51,9 @@ int pclose();
#endif
static void createtag (char *t)
static int gettag (int i)
{
lua_pushnumber(lua_newtag());
lua_rawsetglobal(t);
}
static int gettag (char *t)
{
return lua_getnumber(lua_rawgetglobal(t));
return lua_getnumber(lua_getparam(i));
}
@ -114,24 +110,25 @@ static void closefile (char *name)
}
static void setfile (FILE *f, char *name)
static void setfile (FILE *f, char *name, int tag)
{
lua_pushusertag(f, gettag(IOTAG));
lua_pushusertag(f, tag);
lua_setglobal(name);
}
static void setreturn (FILE *f, char *name)
{
setfile(f, name);
lua_pushusertag(f, gettag(IOTAG));
int tag = gettag(IOTAG);
setfile(f, name, tag);
lua_pushusertag(f, tag);
}
static void io_readfrom (void)
{
FILE *current;
lua_Object f = lua_getparam(1);
lua_Object f = lua_getparam(FIRSTARG);
if (f == LUA_NOOBJECT) {
closefile(FINPUT);
current = stdin;
@ -139,7 +136,7 @@ static void io_readfrom (void)
else if (lua_tag(f) == gettag(IOTAG))
current = lua_getuserdata(f);
else {
char *s = luaL_check_string(1);
char *s = luaL_check_string(FIRSTARG);
current = (*s == '|') ? popen(s+1, "r") : fopen(s, "r");
if (current == NULL) {
pushresult(0);
@ -153,7 +150,7 @@ static void io_readfrom (void)
static void io_writeto (void)
{
FILE *current;
lua_Object f = lua_getparam(1);
lua_Object f = lua_getparam(FIRSTARG);
if (f == LUA_NOOBJECT) {
closefile(FOUTPUT);
current = stdout;
@ -161,7 +158,7 @@ static void io_writeto (void)
else if (lua_tag(f) == gettag(IOTAG))
current = lua_getuserdata(f);
else {
char *s = luaL_check_string(1);
char *s = luaL_check_string(FIRSTARG);
current = (*s == '|') ? popen(s+1,"w") : fopen(s,"w");
if (current == NULL) {
pushresult(0);
@ -174,7 +171,7 @@ static void io_writeto (void)
static void io_appendto (void)
{
char *s = luaL_check_string(1);
char *s = luaL_check_string(FIRSTARG);
FILE *fp = fopen (s, "a");
if (fp != NULL)
setreturn(fp, FOUTPUT);
@ -187,7 +184,7 @@ static void io_appendto (void)
static void io_read (void)
{
int arg = 1;
int arg = FIRSTARG;
FILE *f = getfileparam(FINPUT, &arg);
char *buff;
char *p = luaL_opt_string(arg, "[^\n]*{\n}");
@ -238,7 +235,7 @@ static void io_read (void)
static void io_write (void)
{
int arg = 1;
int arg = FIRSTARG;
FILE *f = getfileparam(FOUTPUT, &arg);
int status = 1;
char *s;
@ -370,11 +367,6 @@ static void errorfb (void)
static struct luaL_reg iolib[] = {
{"setlocale", setloc},
{"readfrom", io_readfrom},
{"writeto", io_writeto},
{"appendto", io_appendto},
{"read", io_read},
{"write", io_write},
{"execute", io_execute},
{"remove", io_remove},
{"rename", io_rename},
@ -386,16 +378,37 @@ static struct luaL_reg iolib[] = {
{"print_stack", errorfb}
};
static struct luaL_reg iolibtag[] = {
{"readfrom", io_readfrom},
{"writeto", io_writeto},
{"appendto", io_appendto},
{"read", io_read},
{"write", io_write}
};
static void openwithtags (void)
{
int iotag = lua_newtag();
int closedtag = lua_newtag();
int i;
for (i=0; i<sizeof(iolibtag)/sizeof(iolibtag[0]); i++) {
/* put both tags as upvalues for these functions */
lua_pushnumber(iotag);
lua_pushnumber(closedtag);
lua_pushCclosure(iolibtag[i].func, 2);
lua_setglobal(iolibtag[i].name);
}
setfile(stdin, FINPUT, iotag);
setfile(stdout, FOUTPUT, iotag);
setfile(stdin, "_STDIN", iotag);
setfile(stdout, "_STDOUT", iotag);
setfile(stderr, "_STDERR", iotag);
}
void lua_iolibopen (void)
{
luaL_openlib(iolib, (sizeof(iolib)/sizeof(iolib[0])));
createtag(IOTAG);
createtag(CLOSEDTAG);
setfile(stdin, FINPUT);
setfile(stdout, FOUTPUT);
setfile(stdin, "_STDIN");
setfile(stdout, "_STDOUT");
setfile(stderr, "_STDERR");
openwithtags();
lua_pushcfunction(errorfb);
lua_seterrormethod();
}