In Windows Explorer a file has three dates: "creation date", "last modified date" and "acquisition date?" (in Italian it is called "data acquisizione". It is important for me because it is the exact date at which, e.g., a photo is taken (the other two dates change upon trasmission, e.g. when sending zipped files. I know functions to get "creation date" and "last modified date", but I do not how to get the "acquisition date?" of a file. Can you help me? All the best, Ovidio Crocicchi
You are trying to obtain a metadata that is only contained in image files, like JPEG.
I had the same problem and I have not found a solution using standard API. Eventually I solve the problem using the metadata-extractor library that can extract EXIF metadata from image files. The library is really user-friendly, this is the code I used:
File file = new File("C:\\myFile.jpg");
Metadata metadata = ImageMetadataReader.readMetadata(file);
Date acquisitionDate = metadata.getDirectory(ExifIFD0Directory.class)
.getDate(ExifIFD0Directory.TAG_DATETIME);
Windows files have 3 file times, all are exposed in the windows API.
Creation Date, Modified Date, Last Accessed Date.
Any other date is an extended property.
There are S/O articles on reading and setting extended properities via C# using the .net framework.
You should also be able to right click on a file in explorer, select properties from the context menu and see all of the extended properties -- c.f. the MS article Retrieving Extended File Properties
ADDED
You mention that these attributes are not copied when the file is copied. This is a very common problem with these extended attribute as many programs do not copy these extended properties when copying a file because they are only loosely coupled to the file and are not copied automatically whenever the file is copied -- as such, they should not rely on them to store important information, and because of this, they are likely to be poorly supported essentially forever -- since programmers won't rely upon them for important information.
Depending upon the target filesystem, there may be no way to copy these extended attributes at all. E.g. drives using FAT32 (common for USB drives).
Related
Looking to create a spreadsheet of all the file data from a folder of files in Windows 10.
Specifically for this example, the "length" of a group of audio files is desired.
All the methods readily available online, such as "copying file path" or opening the folder in a web browser and copy/pasting the data into a new spreadsheet, seem to allow only for a select few attributes to be captured. Namely, file path, size, and date created.
How can one export other, less common, attributes into spreadsheet form?
Couldn't find a simple answer.
Managed to import the file size using a macro.
From there, used a spreadsheet formula to calculate the length of the audio based on the bitrate.
I have created a certificate design with powerpoint.
Now I have to create 100+ copies of it... each with a different name (the recipent).
I was wondering if there was an easy way to do it...
I can have the list of names in excel or txt.
I am open to other ideas as well, like changing the slide into an images and batch processing it in a simple way
You may also try out SlideMight, a tool for merging hierarchical data with PowerPoint templates. SlideMight supports iteration over data, to generate slides or to populate tables. There is more functionality, but you don't seem to need that. SlideMight is in fact a coding system, like mail merge for Word is.
Input data format is at this time just JSON; you would need to convert your Excel sheets first, e.g. using this Excel to JSON add-in for Excel.
There are versions for Windows and Mac OS X.
More information is at www.SlideMight.com
Disclaimer:
I am the owner of Delftware Technology, the company that developed SlideMight.
And I am one of the developers.
This is a question that really belongs in SuperUser, not StackOverflow (which is intended for coding questions, not software how-to-use questions).
But ...
Save your names to a plain notepad TXT file, one name per line.
Start PowerPoint, choose File, Open and point to your TXT file (you may force the matter by choosing . in Files of type:
Apply whatever template you like to the result.
I have a commercial add-in that'll do this and quite a bit more, but from your description, you don't need it.
Are there any rules for file extensions? For example, I wrote some code which reads and writes a byte pattern that is only understood by that specific programm. I'm assuming my anti virus programm won't be too happy if I give it the name "pleasetrustme.exe"... Is it gerally allowed to use those extensions? And what about the lesser known ones, like ".arw"?
You can use any file extension you want (or none at all). Using standard extensions that reflect the actual type of the file just makes things more convenient. On Windows, file extensions control stuff like how the files are displayed in Windows Explorer and what happens when you double click on it.
I wrote some code which reads and writes a byte pattern that is only
understood by that specific programm.
A file extension is only an indication of what type of data will be inside, never a guarantee that certain data formatted in a specific way will be inside the file.
For your own specific data structure it is of course always best to choose an extension that is not already in use for other file formats (or use a general extension like .dat or .bin maybe). This also has the advantage of being able to use an own icon without it being overwritten by other software using the same extension - or the other way around.
But maybe even more important when creating a custom (binary?) file format, is to provide a magic number as the first bytes of that file, maybe followed by a file header structure containing a version number etc. That way your own software can first check the header data to make sure it's the right type and version (for example: anyone could rename any file type to your extension, so your program needs to have a way to do some checks inside the file before reading the remaining data).
We're creating an app that is going to generate some text files on *nix systems with hashed filenames to avoid too-long filenames.
However, it would be nice to tag the files with some metadata that gives a better clue as to what their content is.
Hence my question. Does anyone have any experience with creating files with custom metadata in Ruby?
I've done some searching and there seem to be some (very old) gems that read metadata:
https://github.com/kig/metadata
http://oai.rubyforge.org/
I also found: system file, read write o create custom metadata or attributes extended which seems to suggest that what I need may be at the system level, but dropping down there feels dirty and scary.
Anyone know of libraries that could achieve this? How would one create custom metadata for files generated by Ruby?
A very old but interesting question with no answers!
In order for a file to contain metadata, it has to have a format that has some way (implicitly or explicitly) to describe where and how the metadata is stored.
This can be done by the format, such as having a header that says where the "main" data is stored and where the "metadata" is stored, or perhaps implicitly, such as having a length to the "main" data, and storing metadata as anything beyond the "main" data.
This can also be done by the OS/filesystem by storing information along with the files, such as permission info, modtime, user, and more comprehensive file information like "icon" as you would find with iOS/Windows.
(Note that I am using "quotes" around "main" and "metadata" because the reality is that it's all data, and needs to be stored in some way that tools can retrieve it)
A true text file does not contain any headers or any such file format, and is essentially just a continuous block of characters (disregarding how the OS may store it). This also means that it can be generally opened by any text editor, which will merely read and display all the characters it finds.
So the answer in some sense is that you can't, at least not on a true text file that is truly portable to multiple OS.
A few thoughts on how to get around this:
Use binary at the end of the text file with hope/requirements that their text editor will ignore non-ascii.
Store it in the OS metadata for the file and make it OS specific (such as storing it in the "comments" section that an OS may have for a file.
Store it in a separate file that goes "along with" the file (i.e., file.txt and file.meta) and hope that they keep the files together.
Store it in a separate file and zip the text and the meta file together and have your tool be zip aware.
Come up with a new file format that is not just text but has a text section (though then it can no longer be edited with a text editor).
Store the metadata at the end of the text file in a text format with perhaps comments or some indicator to leave the metadata alone. This is similar to the technique that the vi/vim text editor uses to embed vim commands into a file, it just puts them as comments at the beginning or end of the file.
I'm not sure there are many other ways to accomplish what you want, but perhaps one of those will work.
Products like Picasa build databases that include metadata about files. Captions, keywords locations and the like.
Files have a number of attributes that is dependant on the file type and / or the application that produced the file.
My question is can I programmatically add a tag to a file and then use this tag to search for content.
Eg. Text files include Name, Type, Folder Path, Size, Date Created, Date Modified, Attributes, Owner, Computer. How can I add a "Keywords" attribute?
I am interested in a solution in C# but am primarily asking for help in understanding how this functionality could be implemented in Windows operating systems.
Thank you
You can try to use Extended Attributes, but they don't have a good API in Windows and in general are not widely used. There also exist Alternate Data Streams, but these are ,as the name suggests, data streams, and not attributes.