[asterisk-dev] New wildcards for pattern matching

Nick Lewis Nick.Lewis at atltelecom.com
Tue Feb 23 06:10:10 CST 2010


>> This was already suggested by several 
>> other people, but not yet
>> implemented :-(

The underlying cause of the dialstring injection problem has been stated
by Kevin and Russell so I do not think that new wildcards for pattern
matching should be implemented under the guise of improving security but
rather new functionality

>In addition to previous mail: IMO we need
>a wildcard which matches 0 or more of the 
>previously pattern. (see older discussion)

I think the "zero or more times previous char" proposal would adequately
cover all the other cases. There is no need for a specific zero or more
numeric wildcard or zero or more alphanumeric wildcard. I am
uncomfortable with wildcards for repeating chars and wildcards for char
value ranges being combined as this will lead to a proliferation of
wildcards to cover two orthogonal variables.

In the previous discussion it was regarded as too hard to implement the
full "zero or more times previous char" wildcard proposal but perhaps
the wildcard could be limited to the end of the pattern match in the
same way as the ! wildcard is. 

For example using ~ as a wildcard to mean "zero or more times last char"
it would be possible to limit trailing chars to numeric, alphanumeric or
almost anything

_123[0-9]~
_123[0-9a-zA-Z]~
_123[!-~]~


-- N_L


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