Re: [ ruby-Bugs-2858 ] testing for hardlink with "test(?-, ...)" flawed on Windows

Hi,

At Mon, 21 Nov 2005 01:44:34 +0900,
[e-mail] wrote in [ruby-core:06672]:
> Tested on Windows XP, NTFS, Ruby 1.8.2 (OneClick Installer):
> 
>   $ ri test
> 
> states:
> 
>   "?-  | boolean | True if file1 is a hard link to file2"
> 
> On the specified platform
> 
>   test(?-, "file1", "file2")
> 
> returns true for any "file1" and "file2" that exist, not only
> for hardlinks. It works as expected on my Linux system.

I'm not sure if this works on Win9X or not.


Index: file.c
===================================================================
RCS file: /cvs/ruby/src/ruby/file.c,v
retrieving revision 1.225
diff -U2 -p -r1.225 file.c
--- file.c	18 Nov 2005 09:09:23 -0000	1.225
+++ file.c	21 Nov 2005 01:41:41 -0000
@@ -637,4 +637,31 @@ rb_stat(VALUE file, struct stat *st)
 }
 
+#ifdef _WIN32
+static HANDLE
+w32_stat(VALUE file, BY_HANDLE_FILE_INFORMATION *st)
+{
+    VALUE tmp;
+    HANDLE f, ret = 0;
+
+    rb_secure(2);
+    tmp = rb_check_convert_type(file, T_FILE, "IO", "to_io");
+    if (!NIL_P(tmp)) {
+	OpenFile *fptr;
+
+	GetOpenFile(tmp, fptr);
+	f = (HANDLE)rb_w32_get_osfhandle(fptr->fd);
+    }
+    else {
+	FilePathValue(file);
+	f = CreateFile(StringValueCStr(file), 0, 0, NULL,
+		       OPEN_EXISTING, 0, NULL);
+	if (f == INVALID_HANDLE_VALUE) return f;
+	ret = f;
+    }
+    if (GetFileInformationByHandle(f, st)) return ret;
+    return INVALID_HANDLE_VALUE;
+}
+#endif
+
 /*
  *  call-seq:
@@ -1363,4 +1390,33 @@ test_sticky(VALUE obj, VALUE fname)
 }
 
+static VALUE
+test_identical(VALUE obj, VALUE fname1, VALUE fname2)
+{
+#ifndef _WIN32
+    struct stat st1, st2;
+
+    if (rb_stat(fname1, &st1) < 0) return Qfalse;
+    if (rb_stat(fname2, &st2) < 0) return Qfalse;
+    if (st1.st_dev != st2.st_dev) return Qfalse;
+    if (st1.st_ino != st2.st_ino) return Qfalse;
+#else
+    BY_HANDLE_FILE_INFORMATION st1, st2;
+    HANDLE f1 = 0, f2 = 0;
+    VALUE tmp;
+
+    f1 = w32_stat(fname1, &st1);
+    if (f1 == INVALID_HANDLE_VALUE) return Qfalse;
+    f2 = w32_stat(fname2, &st2);
+    if (f1) CloseHandle(f1);
+    if (f2 == INVALID_HANDLE_VALUE) return Qfalse;
+    if (f2) CloseHandle(f2);
+
+    if (st1.dwVolumeSerialNumber != st2.dwVolumeSerialNumber) return Qfalse;
+    if (st1.nFileIndexHigh != st2.nFileIndexHigh) return Qfalse;
+    if (st1.nFileIndexLow != st2.nFileIndexLow) return Qfalse;
+#endif
+    return Qtrue;
+}
+
 /*
  * call-seq:
@@ -3197,5 +3253,10 @@ rb_f_test(int argc, VALUE *argv)
     }
 
-    if (strchr("-=<>", cmd)) {
+    if (cmd == '-') {
+	CHECK(2);
+	return test_identical(0, argv[1], argv[2]);
+    }
+
+    if (strchr("=<>", cmd)) {
 	struct stat st1, st2;
 
@@ -3205,9 +3266,4 @@ rb_f_test(int argc, VALUE *argv)
 
 	switch (cmd) {
-	  case '-':
-	    if (st1.st_dev == st2.st_dev && st1.st_ino == st2.st_ino)
-		return Qtrue;
-	    return Qfalse;
-
 	  case '=':
 	    if (st1.st_mtime == st2.st_mtime) return Qtrue;
@@ -4176,4 +4232,6 @@ Init_File(void)
     define_filetest_function("sticky?", test_sticky, 1);
 
+    define_filetest_function("identical?", test_identical, 2);
+
     rb_define_singleton_method(rb_cFile, "stat",  rb_file_s_stat, 1);
     rb_define_singleton_method(rb_cFile, "lstat", rb_file_s_lstat, 1);


-- 
Nobu Nakada