auto create log dir

include/spdlog/details/file_helper-inl.h

@@ -29,9 +29,16 @@ SPDLOG_INLINE void file_helper::open(const filename_t &fname, bool truncate)
 {
     close();
     auto *mode = truncate ? SPDLOG_FILENAME_T("wb") : SPDLOG_FILENAME_T("ab");
+    auto folder_name = os::dir_name(fname);
     _filename = fname;
+
     for (int tries = 0; tries < open_tries; ++tries)
     {
+        if (!folder_name.empty())
+        {
+            os::create_dir(folder_name);
+        }
+
         if (!os::fopen_s(&fd_, fname, mode))
         {
             return;
@@ -129,5 +136,6 @@ SPDLOG_INLINE std::tuple<filename_t, filename_t> file_helper::split_by_extension
     // finally - return a valid base and extension tuple
     return std::make_tuple(fname.substr(0, ext_index), fname.substr(ext_index));
 }
+
 } // namespace details
 } // namespace spdlog

include/spdlog/details/os-inl.h

@@ -16,6 +16,7 @@
 #include <cstring>
 #include <ctime>
 #include <string>
+#include <sstream>
 #include <thread>
 #include <array>
 #include <sys/stat.h>
@@ -196,7 +197,7 @@ SPDLOG_INLINE bool file_exists(const filename_t &filename) SPDLOG_NOEXCEPT
 #else
     auto attribs = GetFileAttributesA(filename.c_str());
 #endif
-    return (attribs != INVALID_FILE_ATTRIBUTES && !(attribs & FILE_ATTRIBUTE_DIRECTORY));
+    return attribs != INVALID_FILE_ATTRIBUTES;
 #else // common linux/unix all have the stat system call
     struct stat buffer;
     return (::stat(filename.c_str(), &buffer) == 0);
@@ -460,6 +461,72 @@ SPDLOG_INLINE void wstr_to_utf8buf(wstring_view_t wstr, memory_buf_t &target)
 }
 #endif // (defined(SPDLOG_WCHAR_TO_UTF8_SUPPORT) || defined(SPDLOG_WCHAR_FILENAMES)) && defined(_WIN32)
 
+// return true on success
+SPDLOG_INLINE bool mkdir_(const filename_t &path)
+{
+#ifdef _WIN32
+#ifdef SPDLOG_WCHAR_FILENAMES
+    return ::_wmkdir(path.c_str()) == 0;
+#else
+    return ::_mkdir(path.c_str()) == 0;
+#endif
+#else
+    return ::mkdir(path.c_str(), mode_t(0755)) == 0;
+#endif
+}
+
+// create the given directory - and all directories leading to it
+// return true on success
+SPDLOG_INLINE bool create_dir(filename_t path)
+{
+    if (file_exists(path))
+    {
+        return true;
+    }
+    using char_type = filename_t::value_type;
+    std::basic_istringstream<char_type> istream(path);
+    filename_t token;
+    filename_t cur_dir;
+    char_type sep = '/';
+
+#ifdef _WIN32
+    // support forward slash in windows
+    std::replace(path.begin(), path.end(), char_type('\\'), sep);
+#endif
+    while (std::getline(istream, token, sep))
+    {
+        if (!token.empty())
+        {
+            cur_dir += token;
+            if (!file_exists(cur_dir) && !mkdir_(cur_dir))
+            {
+                return false;
+            }
+        }
+        cur_dir += sep;
+    }
+
+    return true;
+}
+
+// Return directory name from given path or empty string
+// "abc/file" => "abc"
+// "abc/" => "abc"
+// "abc" => ""
+// "abc///" => "abc"
+SPDLOG_INLINE filename_t dir_name(filename_t path)
+{
+    using char_type = filename_t::value_type;
+    char_type sep = '/';
+
+#ifdef _WIN32
+    // support forward slash in windows
+    std::replace(path.begin(), path.end(), char_type('\\'), sep);
+#endif
+    auto pos = path.find_last_of(sep);
+    return pos != filename_t::npos ? path.substr(0, pos) : filename_t{};
+}
+
 } // namespace os
 } // namespace details
 } // namespace spdlog

include/spdlog/details/os.h

@@ -89,6 +89,17 @@ bool in_terminal(FILE *file) SPDLOG_NOEXCEPT;
 void wstr_to_utf8buf(wstring_view_t wstr, memory_buf_t &target);
 #endif
 
+// Return directory name from given path or empty string
+// "abc/file" => "abc"
+// "abc/" => "abc"
+// "abc" => ""
+// "abc///" => "abc"
+filename_t dir_name(filename_t path);
+
+// Create a dir from the given path.
+// Return true if succeeded or if this dir already exists.
+bool create_dir(filename_t path);
+
 } // namespace os
 } // namespace details
 } // namespace spdlog