File handling question...

I have a class that I am using to Log Debug Messages in ".log" files.

The problem I am having is getting the class to only save 30 log files.

So if I have file: Log_1.log, etc, etc, Log_30.log then I want the program to delete Log_1.log and save the new Debug log as Log_31.log. That way the names don't lost meaning.

I have tried, and tried, and tried. It must be something simple that I am overlooking.
I have the following code. It will only save 10 files, and I have absolutely no idea what it is doing. Any assistance would be greatly appreciated.

Also, as far as the code that finds the files. I am 100% sure that it works the way it is suppose to.

Code:

---

MT_Log::MT_Log()
{
    //Gather all files, and store them in filelist
    flist list;
    BuildFileList(list);

    int FirstFileID = 0;
    int LastFileID = 0;

    int FileID = 0;
    //Get first filename from list
    if ( list.files != 0 )
    {
        std::stringstream NameParser;
        std::string FileName;
        //Get FileID from filename
        FileName = list.files[0].cFileName;
        NameParser << FileName.substr(FileName.find("Log_")+4, FileName.find(".log"));
        NameParser >> FileID;
    }
   
    FirstFileID = FileID;

    FileID = 0;
    //Get last filename from list
    if ( list.files != 0 )
    {
        std::stringstream NameParser;
        std::string FileName;
        //Get FileID from filename
        FileName = list.files[list.num_entries-1].cFileName;
        NameParser << FileName.substr(FileName.find("Log_")+4, FileName.find(".log"));
        NameParser >> FileID;
    }
    LastFileID = FileID;

    if ( ( FirstFileID+30 ) < LastFileID )
    {
        std::string File = "Logs\\";
        File += list.files[0].cFileName;
        std::remove(File.c_str());
    }

    std::stringstream ss;
    ss << "Logs\\Log_" << LastFileID+1 << ".log";

    log.open(ss.str().c_str(),std::ios::trunc);

    // free the list of files
    free(list.files);
}

---

Thank you SO much if you can help.

when you creating file 31
LastFileID == 30
file to remove is FirstFileID == 1

Code:

---

if ( ( FirstFileID+30 ) < LastFileID )

---

Could you see something wrong in this expression?

PS. free(list.files); - shouldn't it be done by the destructor of th eobject?
Shouldn't you use new/delete pair in C++?

Lol, still not catching the expression problem, but

free(list.files); frees the local list in the constructor.

I am rewriting some things. I was using realloc(). Which I decided against, because it is a pain in the butt.

Code:

---

if ( ( FirstFileID+30 ) < LastFileID )

---

I think you turned that logic backwards.
What you wanted is
If CurrentFileId is greater than the maximum file Id
Or, in other words, something like...

Code:

---

if ( LastFileId >= (FirstFileId + 30) )

---

Found my solution. Pretty much rewrote the whole thing, but here is the solution if anyone ever needs it. ( doubtful )

Code:

---

struct flist
{
  std::vector<WIN32_FIND_DATAA> files;
  std::vector<WIN32_FIND_DATAA>::iterator iter;
};

{
        flist list;
        BuildFileList(list);
        std::vector<int> IDList;
       
        //Populate the IDList vector
        for ( list.iter = list.files.begin(); list.iter != list.files.end(); ++ list.iter )
        {
                int FileID = -1;
                std::stringstream Parser;
                Parser << (*list.iter).substr((*list.iter).find("Log_")+4, (*list.iter).find(".log"));
                Parser >> FileID;
                IDList.push_back(FileID);
        }
       
        //Sort the IDList vector
        std::sort(IDList.begin(), IDList.end());

        //FileID variables
        int LowFileID = 0;
        int HighFileID = -1;

        //Get variables
        if ( IDList.size() != 0 )
        {
                LowFileID = IDList.front();
                HighFileID = IDList.back();
        }
        if ( ( LowFileID+29 ) < HighFileID )
        {
                std::stringstream File;
                File << "Logs\\Log_" << LowFileID << ".log";
                std::remove(File.str().c_str());
        }

        std::stringstream LogFile;
        LogFile << "Logs\\Log_" << HighFileID+1 << ".log";
       
        log.open(LogFile.str().c_str(), std::ios::trunc);
}

---

QUESTION:
Does anyone think that since I am using Win32 that it would make more sense to delete the files by date created, so that tampering won't mess with the order?

That logic is still turned backwards, though ;)

Quote:

---

Originally Posted by Elysia

That logic is still turned backwards, though ;)

---

seems to be ok if diff between High and Low is less than 29 - there is still not enogh files to start removing

Sure it works, but it's backwards in that I think it would be easier to understand if you compared it to current file id is bigger than the maximum allowed instead of the maximum id is lesser than the current.
The second making a little less sense than the first.