How do I get the file date and time

Hello folks,

in my Simulink model I want to create a block which will read from a file from time to time. The file will not be updated every time the block runs, so in order to save the performance for fopen'ing the file I would just like to check on the file date and time.

Is there any handy Matlab function which will return the file's date and time as a number (e.g. double, 32 bit int etc.)

This is for Matlab / Simulink R2012a, running on WinXP.

Thanks for any hints

Norbert

Answer 1

[TAB]

FileInfo = dir('YourFileWithExtention');
TimeStamp = FileInfo.date;

By the way, in which block of simulink you are using fopen.

[Edited 26 Mar, 2012]

% Get individual components of date & time in 1 Sec resolution
FileInfo = dir('YourFileWithExtention');
[Y, M, D, H, MN, S] = datevec(FileInfo.datenum);

Declare datevec as extrinsic before using.

[Jan]

Or: FileInfo.datenum

[Norbert]

Thanks for your answer TAB, it is surely helpful. As I see it this method will give me the file date and time with one minute resolution.

Do you know of a way to also get the seconds of the file date and time?

[TAB]

Above functions always returns time with 1 sec resolution.

FileInfo.date will resurn the whole value as string.

If you are using embedded matlab function block, you can also evaluate the invidual values of Year, date, month.....etc.

Please see my edited answer.

[Jan]

The datenum field contains even fractional seconds.

Answer 2

[Norbert]

Since I only need to detect a change of the file I will now use the Bytes field of the structure and check for a change of size, this will also work for me.

Btw. I am not sure I understand your question. I use a "Matlab Function" block. I have to declare the fopen as "extrinsic" though.

Answer 3

[Tony Jiang]

datestr(FileInfo.date,29) will report the date only without the time info. you can play with the different formatting in datestr though..