@@ -68,8 +68,138 @@ extern char *canonicalize_file_name (const char *);
/* cygwin has realpath, so it won't get here. */
# if defined (_WIN32)
# define WIN32_LEAN_AND_MEAN
-# include <windows.h> /* for GetFullPathName */
-# endif
+# include <windows.h> /* for GetFullPathName/GetFinalPathNameByHandle/
+ CreateFile/CloseHandle */
+# define WIN32_REPLACE_SLASHES(_ptr, _len) \
+ for (unsigned i = 0; i != (_len); ++i) \
+ if ((_ptr)[i] == '\\') (_ptr)[i] = '/';
+
+# define WIN32_UNC_PREFIX "//?/UNC/"
+# define WIN32_UNC_PREFIX_LEN (sizeof(WIN32_UNC_PREFIX)-1)
+# define WIN32_IS_UNC_PREFIX(ptr) \
+ (0 == memcmp(ptr, WIN32_UNC_PREFIX, WIN32_UNC_PREFIX_LEN))
+
+# define WIN32_NON_UNC_PREFIX "//?/"
+# define WIN32_NON_UNC_PREFIX_LEN (sizeof(WIN32_NON_UNC_PREFIX)-1)
+# define WIN32_IS_NON_UNC_PREFIX(ptr) \
+ (0 == memcmp(ptr, WIN32_NON_UNC_PREFIX, WIN32_NON_UNC_PREFIX_LEN))
+
+# define WIN32_IS_SPECIAL_NUL_FILE(ptr) \
+ (0 == memcmp(ptr, "NUL", 3) || 0 == memcmp(ptr, "nul", 3))
+
+/* Get full path name without symlinks resolution.
+ It also converts all forward slashes to back slashes.
+*/
+char* get_full_path_name(const char *filename) {
+ DWORD len;
+ char *buf, *ptr, *res;
+
+ /* determining the required buffer size.
+ from the man: `If the lpBuffer buffer is too small to contain
+ the path, the return value is the size, in TCHARs, of the buffer
+ that is required to hold the path _and_the_terminating_null_character_`
+ */
+ len = GetFullPathName(filename, 0, NULL, NULL);
+
+ if ( len == 0 )
+ return strdup(filename);
+
+ buf = (char *)malloc(len);
+
+ /* no point to check the result again */
+ len = GetFullPathName(filename, len, buf, NULL);
+ buf[len] = 0;
+
+ /* replace slashes */
+ WIN32_REPLACE_SLASHES(buf, len);
+
+ /* calculate offset based on prefix type */
+ len = WIN32_IS_UNC_PREFIX(buf)
+ ? (WIN32_UNC_PREFIX_LEN - 2)
+ : WIN32_IS_NON_UNC_PREFIX(buf)
+ ? WIN32_NON_UNC_PREFIX_LEN
+ : 0
+ ;
+
+ ptr = buf + len;
+ if ( WIN32_IS_UNC_PREFIX(buf) ) {
+ ptr[0] = '/';
+ ptr[1] = '/';
+ }
+
+ res = strdup(ptr);
+
+ free(buf);
+
+ return res;
+}
+
+# if _WIN32_WINNT >= 0x0600
+
+/* Get full path name WITH symlinks resolution.
+ It also converts all forward slashes to back slashes.
+*/
+char* get_final_path_name(HANDLE fh) {
+ DWORD len;
+ char *buf, *ptr, *res;
+
+ /* determining the required buffer size.
+ from the man: `If the function fails because lpszFilePath is too
+ small to hold the string plus the terminating null character,
+ the return value is the required buffer size, in TCHARs. This
+ value _includes_the_size_of_the_terminating_null_character_`.
+ but in my testcase I have path with 26 chars, the function
+ returns 26 also, ie without the trailing zero-char...
+ */
+ len = GetFinalPathNameByHandle(
+ fh
+ ,NULL
+ ,0
+ ,FILE_NAME_NORMALIZED | VOLUME_NAME_DOS
+ );
+
+ if ( len == 0 )
+ return NULL;
+
+ len += 1; /* for zero-char */
+ buf = (char *)malloc(len);
+
+ /* no point to check the result again */
+ len = GetFinalPathNameByHandle(
+ fh
+ ,buf
+ ,len
+ ,FILE_NAME_NORMALIZED | VOLUME_NAME_DOS
+ );
+ buf[len] = 0;
+
+ /* replace slashes */
+ WIN32_REPLACE_SLASHES(buf, len);
+
+ /* calculate offset based on prefix type */
+ len = WIN32_IS_UNC_PREFIX(buf)
+ ? (WIN32_UNC_PREFIX_LEN - 2)
+ : WIN32_IS_NON_UNC_PREFIX(buf)
+ ? WIN32_NON_UNC_PREFIX_LEN
+ : 0
+ ;
+
+ ptr = buf + len;
+ if ( WIN32_IS_UNC_PREFIX(buf) ) {
+ ptr[0] = '/';
+ ptr[1] = '/';
+ }
+
+ res = strdup(ptr);
+
+ free(buf);
+
+ return res;
+}
+
+# endif // _WIN32_WINNT >= 0x0600
+
+# endif // _WIN32
#endif
char *
@@ -128,30 +258,51 @@ lrealpath (const char *filename)
}
#endif
- /* The MS Windows method. If we don't have realpath, we assume we
- don't have symlinks and just canonicalize to a Windows absolute
- path. GetFullPath converts ../ and ./ in relative paths to
- absolute paths, filling in current drive if one is not given
- or using the current directory of a specified drive (eg, "E:foo").
- It also converts all forward slashes to back slashes. */
+ /* The MS Windows method */
#if defined (_WIN32)
{
- char buf[MAX_PATH];
- char* basename;
- DWORD len = GetFullPathName (filename, MAX_PATH, buf, &basename);
- if (len == 0 || len > MAX_PATH - 1)
- return strdup (filename);
- else
- {
- /* The file system is case-preserving but case-insensitive,
- Canonicalize to lowercase, using the codepage associated
- with the process locale. */
- CharLowerBuff (buf, len);
- return strdup (buf);
+ char *res;
+ /* For Windows Vista and greater */
+#if _WIN32_WINNT >= 0x0600
+
+ /* For some reason the function receives just empty `filename`, but not NULL.
+ What should we do in that case?
+ According to `strdup()` implementation
+ (https://elixir.bootlin.com/glibc/latest/source/string/strdup.c)
+ it will alloc 1 byte even for empty but non NULL string.
+ OK, will use `strdup()` for that case.
+ */
+ if ( 0 == strlen(filename) )
+ return strdup(filename);
+
+ if ( WIN32_IS_SPECIAL_NUL_FILE(filename) ) {
+ res = get_full_path_name(filename);
+ } else {
+ HANDLE fh = CreateFile(
+ filename
+ ,FILE_READ_ATTRIBUTES
+ ,FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE
+ ,NULL
+ ,OPEN_EXISTING
+ ,FILE_FLAG_BACKUP_SEMANTICS
+ ,NULL
+ );
+
+ if ( fh == INVALID_HANDLE_VALUE ) {
+ res = get_full_path_name(filename);
+ } else {
+ res = get_final_path_name(fh);
+ CloseHandle(fh);
}
- }
-#endif
+ }
+
+#else
+ /* For Windows XP */
+ res = get_full_path_name(filename);
- /* This system is a lost cause, just duplicate the filename. */
- return strdup (filename);
+#endif // _WIN32_WINNT >= 0x0600
+
+ return res;
+ }
+#endif // _WIN32
}