Delphi checking date to make backup files on a scheduled - delphi

Question

I have a program that writes to a log file and zips it. I want to set it up so that it will take the log file and zip it after a month and clear the file and reset it to do it again if another month has passed
procedure SendToLog(Const MType : twcMTypes; Const callProgram, callPas, callProssecs, EMessage, zipName : String; AddlStr : String = '' );
Const
MTValues = 'EDS';
var
LogFile : TextFile;
LogName : String;
EString : String;
begin
logName := WebLogPath; // þ for delimeter
EString := MTValues[ Ord( MType )+1] + PC + FormatDateTime( 'mm/dd/yyyy hh:nn:ss.zzz', Now )
+ PC + callProgram + PC + callpas + PC + callProssecs + PC + EMessage;
Assign( LogFile, LogName );
if FileExists(LogName) then
Append( LogFile ) { Open to Append }
else
begin
Rewrite( LogFile ); { Create file }
end;
Writeln( LogFile, EString );
Close( LogFile );
ArchiveFiles('C:', 'mytest.log', 'C:', zipName + '.zip', 'M');
I want to know how I make so that every time the program logs something it checks if the a month has passed then it will zip everything into a new file and reset the log.

Answer 1

You would have to either:
keep track of the last write date somewhere, persistently across app restarts.
query the last write date of the log file itself using the Win32 API GetFileTime() function.
put the current date on each log entry that you write, then you can seek to the end of the log file and read the date from the last log entry that was written.
Each time you want to write a new log entry, compare the month+year of the last known date against the current date and then zip+reset the log file if the current date is higher.

Answer 2

http://docwiki.embarcadero.com/Libraries/XE2/en/System.IOUtils.TFile.GetCreationTime
http://docwiki.embarcadero.com/Libraries/XE2/en/System.IOUtils.TFile.AppendAllText
http://docwiki.embarcadero.com/Libraries/XE2/en/System.IOUtils.TFile.Exists
So you just check for creation date and then you decide if you need a new file or not.
procedure SendToLog(Const MType : twcMTypes; Const callProgram, callPas, callProssecs, EMessage, zipName : String; AddlStr : String = '' );
Const
MTValues = 'EDS';
MaxAgeBeforeNewLogFile = 30; // 30 days, in TDateTime type convention
var
LogFile : TextFile;
LogName : String;
EString : String;
NeedZipLogFile : Boolean; ZipName: String;
begin
logName := WebLogPath; // þ for delimeter
EString := MTValues[ Ord( MType )+1] + PC + FormatDateTime( 'mm/dd/yyyy hh:nn:ss.zzz', Now )
+ PC + callProgram + PC + callpas + PC + callProssecs + PC + EMessage;
NeedZipLogFile := False;
if System.IOUtils.TFile.Exists( LogName ) then
NeedZipLogFile := Now() - System.IOUtils.TFile.GetCreationTime( LogName )
> MaxAgeBeforeNewLogFile;
if NeedZipLogFile then begin
ZipName := _Generate_New_Non_Used_And_Proper_Name_For_Archive();
_Save_Log_Into_Zip( LogName );
If _Secure_Keeping_Of_Logs_Is_Very_Very_Important then begin
_Flush_Windows_File_Cache_To_Disk( ZipName );
_Read_Zipped_Log_Into_Memory( ZipName, ExtractFileName( LogName ), _Temp_Memory_Buffer );
_Compare_With_Old_Log_File_And_Ensure_Nothing_Was_Lost( LogName, _Temp_Memory_Buffer);
end;
DeleteFile( LogFile);
end;
System.IOUtils.TFile.AppendAllText( LogFile, EString );
end;