# How would I go about creating a filename with invalid characters such as :?> ?

I need to do create a file with a filename such as :>?, is this possible somehow? Windows stops it.

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Well each restricted character has another meaning or usage, so if a file or folder name did contain them it could cause Bad Things™ to happen. Mind if I ask why you are trying to do this? –  DMA57361 Sep 11 '10 at 18:04
@DMA57361, when I did this a few years ago, I was testing some things. If I recall correctly, the results were amusing but I don’t recally anything specifically bad happening. At most, I was simply unable to access them. (Though I suppose it could cause trouble if for example, you happened to have files named a, b, and a>b and tried to view the last file as using type a>b. Oops.) –  Synetech Nov 30 '13 at 21:49
@moorecast, when I did this a few years ago, I made the files/directories with dummy names, then used a disk-editor to manually set the names in the directory entries directly. Of course that was on a FAT32 volume, so it was very easy. It would be a little harder on an NTFS volume. –  Synetech Nov 30 '13 at 21:51
Mind if I ask why you are trying to do this? Maybe to implement a (poor) copy-protection? –  Synetech Dec 7 '13 at 5:30

Unfortunately, you cannot use the reserved characters when creating folders or files due to them being part of system functions.

What I recommend you do is look through the Character Map application - You can go to run and type charmap.

from here, you may be able to find alternate symbols that look the same, for example:

(copy and paste these, you will see that they are different)

Instead of forward slash / - you can use a division symbol ∕

Instead of Colon : - you can use the modifier letter colon ꞉

and so on!

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Making it even harder to delete! :-) –  Arjan Sep 11 '10 at 18:29
@Arjan - only via command prompt.. even then you can use the tab key for autocomplete. –  William Hilsum Sep 11 '10 at 18:49
/ is a slash - not a backslash –  Dennis Williamson Sep 11 '10 at 19:12
@Dennis Williamson, thanks, edited. –  William Hilsum Sep 11 '10 at 19:44
I used to use this trick for certain situations like when I need to put a question in a filename (why oh why did Microsoft make the question mark reserved‽ ఠ_ఠ) Unfortunately, I had to stop using any non-ASCII characters because they cause problems with things like defrag programs which for some reason seem to be unable to move files that have Unicode characters in their names. ಠ~ಠ –  Synetech Nov 30 '13 at 22:00

You can boot from a Linux disk (such as Knoppix), and mount the NTFS partition.

Linux has much less restrictions on files names, and will let you create such names (I have tried it).

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The only way is to manually edit the hard drive using a program like HxD. If you do this though, most likely the files won't be accessible by any program. For example, if you tried to open a file named abc\def.txt, you'd get a message that the directory abc doesn't exist.

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+1 This is how I did a while back. I was easily able to use every single reserved character by directly editing the FAT directory entries. (It’s also possible in NTFS, but slightly more involved.) –  Synetech Nov 30 '13 at 22:05

Some operating systems prohibit some particular characters from appearing in file names: (Resource from Wikipedia)

/ slash used as a path name component separator in Unix-like, Windows, and Amiga systems. (The MS-DOS command.com shell would consume it as a switch character, but Windows itself always accepts it as a separator[2][vague])

\ backslash Also used as a path name component separator in MS-DOS, OS/2 and Windows (there is no difference between slash and backslash); allowed in Unix filename

? question mark used as a wildcard in Unix, Windows and AmigaOS; marks a single character. Allowed in Unix filenames

* asterisk used as a wildcard in Unix, MS-DOS, RT-11, VMS and Windows. Marks any sequence of characters (Unix, Windows, later versions of MS-DOS) or any sequence of characters in either the basename or extension (thus "." in early versions of MS-DOS means "all files". Allowed in Unix filenames,

: colon used to determine the mount point / drive on Windows; used to determine the virtual device or physical device such as a drive on AmigaOS, RT-11 and VMS; used as a pathname separator in classic Mac OS. Doubled after a name on VMS, indicates the DECnet nodename (equivalent to a NetBIOS (Windows networking) hostname preceded by "\".)

| vertical bar designates software pipelining in Unix and Windows; allowed in Unix filenames

" quotation mark used to mark beginning and end of filenames containing spaces in Windows

< less than used to redirect input, allowed in Unix filenames

> greater than used to redirect output, allowed in Unix filenames

. period allowed but the last occurrence will be interpreted to be the extension separator in VMS, MS-DOS and Windows. In other OSes, usually considered as part of the filename, and more than one full stop may be allowed.

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You can safely dial down the <bold> hyperbole: it is possible to import files with illegal characters, superuser.com/questions/31587. –  hyperslug Sep 11 '10 at 18:28
The question isn’t why can’t I use some characters in filenames; it is how can I force the use of reserved characters. As such, this answer is an answer to a different question. At most, this should be a comment with a link to the Wikipedia article. –  Synetech Nov 30 '13 at 22:10

You can install the Subsystem for Unix Applications if you're on Ultimate or Enterprise. From there you can create such names.

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