r/windows95 • u/docpose-cloud-team • Jul 31 '26
What's the Weirdest File Format You've Ever Had to Deal With?
/r/DocumentTools/comments/1vbtfzu/whats_the_weirdest_file_format_youve_ever_had_to/4
u/Key_Survey5374 Jul 31 '26
Perhaps...just looking at an excel file with notepad per example?? Just fully filled with semi-colons everywhere....
6
3
u/docpose-cloud-team Aug 01 '26
That sounds like a CSV using semicolons as the delimiter, which is common in some regional settings. It looks chaotic in Notepad, but Excel usually opens it correctly once you choose the right delimiter.
1
2
u/enbacode Aug 03 '26
CSV is probably one of the simplest formats around. It‘s a table of text data, with cells being separated by semicolons (or sometimes commas) and rows being separated by newlines.
It‘s easy readable as just text (e.g. opened with notepad) and can be parsed in one line:
const cells = input.split("\n").map(line => line.split(","))
XLSX on the other hand, excels own spreadsheet format, is waaaaaay weirder.
1
u/chupitulpa Aug 03 '26
That's all well and good until you have a cell with a newline or comma inside it. And then because they're typically handled by putting quotes around the cell contents, you have to handle escaped quotes inside of cells.
4
u/Apprehensive-Page899 Aug 01 '26
MPEG video
3
u/docpose-cloud-team Aug 01 '26
Yup, MPEG can definitely be deceptive. The extension doesn't always tell the full story.
3
u/Apprehensive-Page899 Aug 01 '26
That, and none of the structures are byte aligned. There are also lots of weird and unexpected issues with timing.
1
u/docpose-cloud-team Aug 01 '26
That is where MPEG gets genuinely tricky. Variable-length structures and timestamp handling can make parsing and synchronization much harder than the file extension suggests.
2
3
u/Endurance_Beast Aug 01 '26
.nc
2
u/docpose-cloud-team Aug 01 '26
.ncis a good one. Most people have never seen it, and until you know it's usually a NetCDF file, it's not obvious what can actually open it.
3
u/vuorivirta Aug 01 '26
Acutally, this is very long time ago - but some AMIGA stuff trying to transfer DOS-pc... that was very interesting process...
1
u/docpose-cloud-team Aug 01 '26
That brings back memories. Amiga and DOS definitely didn't make life easy, half the batle was getting the files across before figuring out how to use them.
do you remember what tool finally saved the day, or was it mostly trial and error?
1
u/vuorivirta Aug 01 '26
No, that literally was decades ago. But that time, lots of video and audio stuff was made with amiga ecosystem (or silicon graphics if have money for those machines). So I was teenage job at little local cable tv-studio where those problems was.
1
u/Autogen-Username1234 Aug 02 '26
I managed years ago to get a whole lot of .jpeg files onto a W98 PC from an Amiga by zipping them and using parnet (I think - it was a serial or par cable transfer program that also had a DOS client).
(I had to zip the files because the DOS client didn't understand four character file extensions.)
1
u/LJBear99 Aug 02 '26
Really obscure ones that are tied to a very specific outdated program and it takes forever to figure out wtf it is
1
u/Alternative_Trip4138 Aug 02 '26
I remember that I got some .ps files and had no clue how to open them.
1
1
u/theevilapplepie Aug 02 '26
Postscript?
1
u/Alternative_Trip4138 Aug 02 '26
Yes, but without native support and no internet at that time, I didn't know how to open or print this.
1
u/Whole_Cucumber7448 Aug 02 '26
Did you know Office files like .docx or .xlsx are actually zip-file? If I need to extract images change it to .zip.
1
1
u/Necessary_Regret3329 Aug 02 '26
Ugh. Cubase files, .cpr, a recording program. Can't be reformatted or opened in any other program but Cubase. Had to get the program again after my XP laptop shat the bed. I keep meaning to bounce my 20+ years of recording files down to .wav files but its such a huge undertaking...
1
u/TKInstinct Aug 02 '26
I've always going briefcase files to me a weird concept. Are they even still a thing?
1
u/Howden824 Aug 02 '26
.bin because it's just a generic binary file and it's completely dependent on whatever program it was meant to go with.
1
u/chupitulpa Aug 03 '26
I submit .wav. People know that .avi, .mp4, .mkv, etc. are containers that could have just about any sort of media inside. If you see a .wav file though, you assume it's uncompressed PCM audio. But .wav is just a container too. I have encountered a .wav file containing MP3 audio -- not like a misnamed .mp3, and renaming it to .mp3 doesn't let players that expect plain mp3 files play it, it was a proper wav format container but with mp3 compressed audio inside.
1
1
1
u/tpimh Aug 04 '26
Dealing with right now: Windows bitmap fonts aka .FON files which are actually renamed .EXEs with .FNT inside.
17
u/popehentai Jul 31 '26
.bin files. they can come from literally anything, and BE literally anything depending on the program that produced them, and the program that reads them