# PC Truncates My File's Name When Copying? **URL:** \ **Category:** Factual Questions\ **Created:** [May 24, 2004, 3:52pm UTC](https://boards.straightdope.com/t/pc-truncates-my-files-name-when-copying/246807 "2004-05-24T15:52:26Z")\ **Posts on this page:** 11\ **Page:** 1
**Author:** ![Jinx](https://avatars.discourse-cdn.com/v4/letter/j/c6cbf5/32.png) [@Jinx](https://boards.straightdope.com/u/Jinx)\ **Post date:** [May 24, 2004, 3:52pm UTC](https://boards.straightdope.com/t/pc-truncates-my-files-name-when-copying/246807/1 "2004-05-24T15:52:26Z")
Here’s a puzzle for the real PC gurus. I have files with long, descriptive names which is necessary since these documents all look and sound alike. Anyway, when burning them onto a CD, I have found one document where the name of the file has been shortened from the original by EXACTLY two words! To be exact about this, I have viewed “Details” for both the original document and the copy. And yes, I expanded this field under “Details” as wide as possible until the ellipses disappears. The copied file name IS missing the last two words! There is no “~” symbol, no ellipses shown, and oddly…it is PRECISELY two full words - not even like a word was cut off! Has anyone else experienced this? What the heck? Yet another MS bug? Must be a cicada thing, and I wouldn’t understand… 😉 Please assure me I am _not_ going crazy! Is my PC playing mind games with me??? - Jinx ---
**Author:** ![Rex\_Fenestrarum](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/rex_fenestrarum/32/7265_2.png) [@Rex\_Fenestrarum](https://boards.straightdope.com/u/Rex_Fenestrarum)\ **Post date:** [May 24, 2004, 4:01pm UTC](https://boards.straightdope.com/t/pc-truncates-my-files-name-when-copying/246807/2 "2004-05-24T16:01:37Z")
Nah, it’s not an “MS bug”. It’s a limittation of the CD-ROM standard. ISO file names are limited to 11 characters (often called 8+3, for the DOS-style MYFILN~1.DOC). Joliet is limited to 255 characters (I think). When I used to backup my MP3s to CD-ROM, I would RAR (a type of ZIP) the files up just to preserve the long filenames, as I don’t think there’s any other way around this limitation. What burning software are you using? If you try to burn a CD with a really long filename on it with Nero, it will tell you that “The file names: XXX is too long and will be truncated to fit the ISO\Joliet standard” or some such… ---
**Author:** ![Jinx](https://avatars.discourse-cdn.com/v4/letter/j/c6cbf5/32.png) [@Jinx](https://boards.straightdope.com/u/Jinx)\ **Post date:** [May 24, 2004, 4:23pm UTC](https://boards.straightdope.com/t/pc-truncates-my-files-name-when-copying/246807/3 "2004-05-24T16:23:09Z")
> [@Rex Fenestrarum](#): > > What burning software are you using? If you try to burn a CD with a really long filename on it with Nero, it will tell you that “The file names: XXX is too long and will be truncated to fit the ISO\Joliet standard” or some such… There is no message warning me of this. This sounds stupid, but I don’t know what software I am using, per se. First, I copy files to the “D:” drive. When this is completed, a right-click of the mouse allows me to write these files to the disc. It is all done via Windows without the need for a CD-Rom burning software package. So, what method (or standard) is it employing, would you WAG? Hmm, other than a possible reboot - where do I click to find out what version of Windows I am running? I believe it is Windows 2000 Professional. - Jinx ---
**Author:** ![Jinx](https://avatars.discourse-cdn.com/v4/letter/j/c6cbf5/32.png) [@Jinx](https://boards.straightdope.com/u/Jinx)\ **Post date:** [May 24, 2004, 4:26pm UTC](https://boards.straightdope.com/t/pc-truncates-my-files-name-when-copying/246807/4 "2004-05-24T16:26:10Z")
Hey, you’ve sparked another related question: If the extension gets truncated off the file name…why doesn’t this cause the PC serious heartburn? Often, when I rename a file, I inadvertently delete the extension off the end, but Windows will warn me my file may be not be able to be opened, or words to this effect… So, once truncated off…how does my PC still know what kind of file it is??? - Jinx ---
**Author:** ![Rex\_Fenestrarum](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/rex_fenestrarum/32/7265_2.png) [@Rex\_Fenestrarum](https://boards.straightdope.com/u/Rex_Fenestrarum)\ **Post date:** [May 24, 2004, 4:33pm UTC](https://boards.straightdope.com/t/pc-truncates-my-files-name-when-copying/246807/5 "2004-05-24T16:33:22Z")
To find out what version of Windows you are using, right-click on My Computer or click Start \> Run \> winver. Any burning software built-in to Windows is from Roxio. I thught it was only included with XP, but I could be wrong. Or it could just be packet writing software added after the fact. Nero always truncates the filename itself, not the extension. I’ve only used the XP burning software in emercencies out in the field to burn a file or two and never had any experience with how it truncates LFNs. I suspect QED will be in here to give his two-bits… maybe he’s used Win2k software… ---
**Author:** ![Musicat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/musicat/32/20189_2.png) [@Musicat](https://boards.straightdope.com/u/Musicat)\ **Post date:** [May 24, 2004, 4:35pm UTC](https://boards.straightdope.com/t/pc-truncates-my-files-name-when-copying/246807/6 "2004-05-24T16:35:50Z")
As long as you’re not using DOS anywhere along the copy path, your most severe restriction will be the standard for CD writing, ISO 9660: > [@](#): > > The File or Directory Identifiers may be up to 128 bytes (64 unicode characters) in length. From [Joliet Specification.](http://bmrc.berkeley.edu/people/chaffee/jolspec.html) I’m unsure whether that means, in a practical sense, if the max chars are 64 or 128. I think the Adaptec burning progs I have used trap those above 64 and offer solutions (like renaming a file) on the fly. Nero should, too. If you aren’t getting warnings, maybe it’s time to use different software. > [@Jinx](#): > > So, once truncated off…how does my PC still know what kind of file it is??? It doesn’t, unless you tell it. ---
**Author:** ![Lagged2Death](https://avatars.discourse-cdn.com/v4/letter/l/ac8455/32.png) [@Lagged2Death](https://boards.straightdope.com/u/Lagged2Death)\ **Post date:** [May 24, 2004, 4:35pm UTC](https://boards.straightdope.com/t/pc-truncates-my-files-name-when-copying/246807/7 "2004-05-24T16:35:58Z")
> [@Rex Fenestrarum](#): > > [The] Joliet [file system for CD-Rs] is limited to 255 characters (I think). Actually, it’s only 64 characters, which is why it becomes a problem so often. I just _hate_ this. I think **Jinx** , that you would get more predicatable and better results from a dedicated CD-burning application like Roxio EasyCD or Nero Burning Rom, one of which is included free with most CD-R hardware. If you’re going to be burning a lot of discs, climbing the learning curve (which really isn’t very steep) will time well spent. ---
**Author:** ![Rex\_Fenestrarum](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/rex_fenestrarum/32/7265_2.png) [@Rex\_Fenestrarum](https://boards.straightdope.com/u/Rex_Fenestrarum)\ **Post date:** [May 24, 2004, 4:44pm UTC](https://boards.straightdope.com/t/pc-truncates-my-files-name-when-copying/246807/8 "2004-05-24T16:44:34Z")
Sorry, it _is_ 64 characters. 255 characters is the limited within Windows. This is what happens when you wake up at 10am on Friday and don’t go back to sleep until 3am Monday… ---
**Author:** ![Jinx](https://avatars.discourse-cdn.com/v4/letter/j/c6cbf5/32.png) [@Jinx](https://boards.straightdope.com/u/Jinx)\ **Post date:** [May 24, 2004, 4:48pm UTC](https://boards.straightdope.com/t/pc-truncates-my-files-name-when-copying/246807/9 "2004-05-24T16:48:51Z")
> [@](#): > > So, once truncated off…how does my PC still know what kind of file it is??? > It doesn’t, unless you tell it. Wait, but it does know! It is an Adobe file, and it knows how to open it…even with the name truncated! Are you sure the extension really counts when counting characters in a file name? - Jinx ---
**Author:** ![Musicat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/musicat/32/20189_2.png) [@Musicat](https://boards.straightdope.com/u/Musicat)\ **Post date:** [May 24, 2004, 6:10pm UTC](https://boards.straightdope.com/t/pc-truncates-my-files-name-when-copying/246807/10 "2004-05-24T18:10:16Z")
Are you sure you are seeing the extension field? Default Windows display is to hide it. I’m very sure that the 1…3 char extension is what traditional Windows (…98) uses to tell what kind of file and link that to what app to use with it, because if I change the extension, the app changes. No extension either cannot be opened at all or defaults to something. It is possible that 2000/XP does things differently; I don’t have one of those systems where I am now to test it. Is it possible, as others have suggested, that your file names became truncated intelligently? That is, the file name _sans_ extension was shortened, then the extension stuck back on? And if your ext display were off, you wouldn’t see the complete result. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [May 25, 2004, 11:58am UTC](https://boards.straightdope.com/t/pc-truncates-my-files-name-when-copying/246807/11 "2004-05-25T11:58:31Z")
The built in XP CD burner is smart enough to preserve the extension. So if you have an 90 character name witha 4 character extension, it reserves 4 chars for that, plus 1 for the period, and that leaves 64-5 = 59 chars for the name. So the file names becomes (shortened name).originalextension Not so tough.