better the old way, using upvalues to keep iotag.

author: Roberto Ierusalimschy <roberto@inf.puc-rio.br> 1999-04-05 16:47:05 -0300
committer: Roberto Ierusalimschy <roberto@inf.puc-rio.br> 1999-04-05 16:47:05 -0300
commit: de04533dc020553a94ecb16480e55e51b1368dbf (patch)
tree: fc4bf9799f25a7a33405fba850ee8f8eca3557a9 /liolib.c
parent: 7c9aee64c250e6f56b5788479d62ff9cbc6ad634 (diff)
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1 files changed, 52 insertions, 45 deletions
diff --git a/liolib.c b/liolib.c
index df6d8c91..85efea5e 100644
--- a/liolib.c
+++ b/liolib.c
@@ -1,5 +1,5 @@
 /*
-** $Id: liolib.c,v 1.35 1999/03/16 20:07:54 roberto Exp roberto $
+** $Id: liolib.c,v 1.36 1999/03/26 13:48:26 roberto Exp roberto $
 ** Standard I/O (and system) library
 ** See Copyright Notice in lua.h
 */
@@ -32,21 +32,25 @@
 #endif
-#define CLOSEDTAG(tag)  ((tag)-1)
+#define IOTAG   1
+#define FIRSTARG        2  /* 1st is upvalue */
+#define CLOSEDTAG(tag)  ((tag)-1)  /* assume that CLOSEDTAG = iotag-1 */
 #define FINPUT          "_INPUT"
 #define FOUTPUT         "_OUTPUT"
-#define MODESIZE        3 /* string for file mode */
 #ifdef POPEN
 FILE *popen();
 int pclose();
+#define CLOSEFILE(f)    {if (pclose(f) == -1) fclose(f);}
 #else
 /* no support for popen */
 #define popen(x,y) NULL  /* that is, popen always fails */
-#define pclose(x)  (-1)
+#define CLOSEFILE(f)    {fclose(f);}
 #endif
@@ -69,8 +73,7 @@ static void pushresult (int i) {
 */
 static int gettag (void) {
-  lua_pushusertag(stdin, LUA_ANYTAG);
+  return (int)lua_getnumber(lua_getparam(IOTAG));
-  return lua_tag(lua_pop());  /* get the tag of stdin */
 }
@@ -117,17 +120,10 @@ static FILE *getfileparam (char *name, int *arg) {
 }
-static void rawclose (FILE *f) {
-  if (f != stdin && f != stdout) {
-    if (pclose(f) == -1) fclose(f);
-  }
-}
 static void closefile (FILE *f) {
  if (f != stdin && f != stdout) {
    int tag = gettag();
-    rawclose(f);
+    CLOSEFILE(f);
    lua_pushusertag(f, tag);
    lua_settag(CLOSEDTAG(tag));
  }
@@ -135,22 +131,20 @@ static void closefile (FILE *f) {
 static void io_close (void) {
-  closefile(getnonullfile(1));
+  closefile(getnonullfile(FIRSTARG));
 }
 static void gc_close (void) {
-  int tag = luaL_check_int(1);
+  FILE *f = getnonullfile(FIRSTARG);
-  lua_Object fh = lua_getparam(2);
+  if (f != stdin && f != stdout && f != stderr) {
-  FILE *f = lua_getuserdata(fh);
+    CLOSEFILE(f);
-  luaL_arg_check(lua_isuserdata(fh) && lua_tag(fh) == tag, 2,
+  }
-                 "invalid file handle for GC");
-  rawclose(f);
 }
 static void io_open (void) {
-  FILE *f = fopen(luaL_check_string(1), luaL_check_string(2));
+  FILE *f = fopen(luaL_check_string(FIRSTARG), luaL_check_string(FIRSTARG+1));
  if (f) lua_pushusertag(f, gettag());
  else pushresult(0);
 }
@@ -171,7 +165,7 @@ static void setreturn (FILE *f, char *name) {
 static void io_readfrom (void) {
  FILE *current;
-  lua_Object f = lua_getparam(1);
+  lua_Object f = lua_getparam(FIRSTARG);
  if (f == LUA_NOOBJECT) {
    closefile(getfilebyname(FINPUT));
    current = stdin;
@@ -179,7 +173,7 @@ static void io_readfrom (void) {
  else if (lua_tag(f) == gettag())  /* deprecated option */
    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);
@@ -192,7 +186,7 @@ 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(getfilebyname(FOUTPUT));
    current = stdout;
@@ -200,7 +194,7 @@ static void io_writeto (void) {
  else if (lua_tag(f) == gettag())  /* deprecated option */
    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);
@@ -212,7 +206,7 @@ static void io_writeto (void) {
 static void io_appendto (void) {
-  FILE *fp = fopen(luaL_check_string(1), "a");
+  FILE *fp = fopen(luaL_check_string(FIRSTARG), "a");
  if (fp != NULL)
    setreturn(fp, FOUTPUT);
  else
@@ -317,7 +311,7 @@ static void read_file (FILE *f) {
 static void io_read (void) {
  static char *options[] = {"*n", "*l", "*a", ".*", "*w", NULL};
-  int arg = 1;
+  int arg = FIRSTARG;
  FILE *f = getfileparam(FINPUT, &arg);
  char *p = luaL_opt_string(arg++, "*l");
  do { /* repeat for each part */
@@ -351,7 +345,7 @@ 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;
@@ -365,10 +359,10 @@ static void io_write (void) {
 static void io_seek (void) {
  static int mode[] = {SEEK_SET, SEEK_CUR, SEEK_END};
  static char *modenames[] = {"set", "cur", "end", NULL};
-  FILE *f = getnonullfile(1);
+  FILE *f = getnonullfile(FIRSTARG);
-  int op = luaL_findstring(luaL_opt_string(2, "cur"), modenames);
+  int op = luaL_findstring(luaL_opt_string(FIRSTARG+1, "cur"), modenames);
-  long offset = luaL_opt_long(3, 0);
+  long offset = luaL_opt_long(FIRSTARG+2, 0);
-  luaL_arg_check(op != -1, 2, "invalid mode");
+  luaL_arg_check(op != -1, FIRSTARG+1, "invalid mode");
  op = fseek(f, offset, mode[op]);
  if (op)
    pushresult(0);  /* error */
@@ -378,8 +372,8 @@ static void io_seek (void) {
 static void io_flush (void) {
-  FILE *f = getfile(1);
+  FILE *f = getfile(FIRSTARG);
-  luaL_arg_check(f || lua_getparam(1) == LUA_NOOBJECT, 1,
+  luaL_arg_check(f || lua_getparam(FIRSTARG) == LUA_NOOBJECT, FIRSTARG,
                 "invalid file handle");
  pushresult(fflush(f) == 0);
 }
@@ -532,44 +526,57 @@ static void errorfb (void) {
 static struct luaL_reg iolib[] = {
  {"_ERRORMESSAGE", errorfb},
-  {"appendto", io_appendto},
  {"clock",     io_clock},
-  {"closefile",   io_close},
  {"date",     io_date},
  {"debug",    io_debug},
  {"execute",  io_execute},
  {"exit",     io_exit},
-  {"flush",     io_flush},
  {"getenv",   io_getenv},
+  {"remove",   io_remove},
+  {"rename",   io_rename},
+  {"setlocale", setloc},
+  {"tmpname",   io_tmpname}
+};
+static struct luaL_reg iolibtag[] = {
+  {"appendto", io_appendto},
+  {"closefile",   io_close},
+  {"flush",     io_flush},
  {"openfile",   io_open},
  {"read",     io_read},
  {"readfrom", io_readfrom},
-  {"remove",   io_remove},
-  {"rename",   io_rename},
  {"seek",     io_seek},
-  {"setlocale", setloc},
-  {"tmpname",   io_tmpname},
  {"write",    io_write},
  {"writeto",  io_writeto}
 };
-void lua_iolibopen (void) {
+static void openwithtags (void) {
+  int i;
  int iotag = lua_newtag();
  lua_newtag();  /* alloc CLOSEDTAG: assume that CLOSEDTAG = iotag-1 */
+  for (i=0; i<sizeof(iolibtag)/sizeof(iolibtag[0]); i++) {
+    /* put iotag as upvalue for these functions */
+    lua_pushnumber(iotag);
+    lua_pushcclosure(iolibtag[i].func, 1);
+    lua_setglobal(iolibtag[i].name);
+  }
  /* predefined file handles */
  setfile(stdin, FINPUT, iotag);
  setfile(stdout, FOUTPUT, iotag);
  setfile(stdin, "_STDIN", iotag);
  setfile(stdout, "_STDOUT", iotag);
  setfile(stderr, "_STDERR", iotag);
-  /* make sure stdin (with its tag) won't be collected */
-  lua_pushusertag(stdin, iotag); lua_ref(1);
  /* close file when collected */
  lua_pushnumber(iotag);
  lua_pushcclosure(gc_close, 1); 
  lua_settagmethod(iotag, "gc");
+}
+void lua_iolibopen (void) {
  /* register lib functions */
  luaL_openlib(iolib, (sizeof(iolib)/sizeof(iolib[0])));
+  openwithtags();
 }
author	Roberto Ierusalimschy <roberto@inf.puc-rio.br>	1999-04-05 16:47:05 -0300
committer	Roberto Ierusalimschy <roberto@inf.puc-rio.br>	1999-04-05 16:47:05 -0300
commit	de04533dc020553a94ecb16480e55e51b1368dbf (patch)
tree	fc4bf9799f25a7a33405fba850ee8f8eca3557a9 /liolib.c
parent	7c9aee64c250e6f56b5788479d62ff9cbc6ad634 (diff)
download	lua-de04533dc020553a94ecb16480e55e51b1368dbf.tar.gz lua-de04533dc020553a94ecb16480e55e51b1368dbf.tar.bz2 lua-de04533dc020553a94ecb16480e55e51b1368dbf.zip