Are there invalid directory characters?

ootawata · 08-19-2009, 03:24 PM

What is illegal to have in a directory path? I've noticed that you can do:

Code:

mkdir '!@#$%^&*()-_=+[]{};:,.<>? '

I can't seem to get a path with ', ", or / in this. I tried escape characters but I can't get them to be with the other characters. For example, this works:

Code:

mkdir "'\"\/"

but I can't do

Code:

mkdir "!@#$"

The above gives this error:

Code:

bash: !@#$: event not found

I know that having symbols for directory names is...silly, but I'm curious.

Nevahre · 08-19-2009, 03:40 PM

Nothing is illegal I think, and mostcan be done:

mkdir '!@#$'
/tmp/Tets $ ls -l
total 4
drwxr-x--- 2 nevahre users 4096 Aug 19 22:37 !@#$

I don't think its wise to use anything else than: A-Z a-z 0-9 _-. (maybe 1 or 2 more).

w1k0 · 08-19-2009, 04:13 PM

A rule of thumb is to use:

A-Z
a-z
0-9
_ (underscore)
- (hyphen)
+ (plus)
space
. (dot)

For the best compatibility is better to avoid spaces and use underscores instead.

I have nice MP3 collection. When I prepared it I stated that Linux doesn't accept / in file's names because that character stands in Linux for subdirectory so I used instead \.

Recently I shared my MP3 collection with my friend. I use Slackware with ReiserFS. He has external hard disk with FAT32.

During copying files I observed that FAT32 doesn't accept some characters in file's names. It doesn't accept \ because that character stands in Windows for subdirectory. I tried | instead but Windows doesn't accept it too for some reason. So finally I used -. Instead of : I was forced to use ;. And finally I was forced to give " up.

So instead of use:

04 Evolution of a Pearl (Part 1/Part 2).mp3
04 Evolution of a Pearl (Part 1\Part 2).mp3
04 Evolution of a Pearl (Part 1|Part 2).mp3
11 Why?.mp3
01 Ghosts: First Variation.mp3
09 Take the "A" Train.mp3

I was forced to use:

04 Evolution of a Pearl (Part 1-Part 2).mp3
11 Why.mp3
01 Ghosts; First Variation.mp3
09 Take the A Train.mp3

In MP3 file's names I use also those characters:

!
#
%
&
'
(
)
,
;
=
[
]

ootawata · 08-20-2009, 12:17 PM

I found out that you cannot use "/" or "/000" (it may have been \000). Not sure why the latter is not allowed.

Valery Reznic · 08-20-2009, 10:29 PM

Quote:

Originally Posted by ootawata

I found out that you cannot use "/" or "/000" (it may have been \000). Not sure why the latter is not allowed.

"/" is hard coded in the kernel as directory separator, so it's can't be part of the name.
"\000" - mkdir (and all other file-name related syscalls) expect to get null terminated string.
So \000 considered as "end of the string"