Regex for valid sharepoint folder name - regex

Question

I am trying to make regular expression for Valid sharepoint folder name, which have conditions:
Cannot begin or end with a dot,
Cannot contain consecutive dots and
Cannot contain any of the following characters: ~ " # % & * : < > ? / \ { | }.
Wrote Regex for 1st and 3rd point:
[^\.]([^~ " # % & * : < > ? / \ { | }]+) [^\.]$
and for third (?!.*\.\.).*)$ but they are not working properly and have to integrate them into one expression.
Please help.

Answer 1

What about just
^\w(?:\w+\.?)*\w+$
I made a small test here
EDIT
This also works
^\w(?:\w\.?)*\w+$

Answer 2

How about:
/^(?!^\.)(?!.*\.$)(?!.*\.\.)(?!.*[~"#%&*:<>?\/\\{|}]+).+$/
explanation:
The regular expression:
(?-imsx:^(?!^\.)(?!.*\.$)(?!.*\.\.)(?!.*[~"#%&*:<>?/\\{|}]+).+$)
matches as follows:
NODE EXPLANATION
----------------------------------------------------------------------
(?-imsx: group, but do not capture (case-sensitive)
(with ^ and $ matching normally) (with . not
matching \n) (matching whitespace and #
normally):
----------------------------------------------------------------------
^ the beginning of the string
----------------------------------------------------------------------
(?! look ahead to see if there is not:
----------------------------------------------------------------------
^ the beginning of the string
----------------------------------------------------------------------
\. '.'
----------------------------------------------------------------------
) end of look-ahead
----------------------------------------------------------------------
(?! look ahead to see if there is not:
----------------------------------------------------------------------
.* any character except \n (0 or more times
(matching the most amount possible))
----------------------------------------------------------------------
\. '.'
----------------------------------------------------------------------
$ before an optional \n, and the end of
the string
----------------------------------------------------------------------
) end of look-ahead
----------------------------------------------------------------------
(?! look ahead to see if there is not:
----------------------------------------------------------------------
.* any character except \n (0 or more times
(matching the most amount possible))
----------------------------------------------------------------------
\. '.'
----------------------------------------------------------------------
\. '.'
----------------------------------------------------------------------
) end of look-ahead
----------------------------------------------------------------------
(?! look ahead to see if there is not:
----------------------------------------------------------------------
.* any character except \n (0 or more times
(matching the most amount possible))
----------------------------------------------------------------------
[~"#%&*:<>?/\\{|}] any character of: '~', '"', '#', '%',
+ '&', '*', ':', '<', '>', '?', '/', '\\',
'{', '|', '}' (1 or more times (matching
the most amount possible))
----------------------------------------------------------------------
) end of look-ahead
----------------------------------------------------------------------
.+ any character except \n (1 or more times
(matching the most amount possible))
----------------------------------------------------------------------
$ before an optional \n, and the end of the
string
----------------------------------------------------------------------
) end of grouping
----------------------------------------------------------------------
In action (perl script):
my $re = qr/^(?!^\.)(?!.*\.$)(?!.*\.\.)(?!.*[~"#%&*:<>?\/\\{|}]+).+$/;
while(<DATA>) {
chomp;
say /$re/ ? "OK : $_" : "KO : $_";
}
__DATA__
.abc
abc.
a..b
abc
output:
KO : .abc
KO : abc.
KO : a..b
OK : abc