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Re: atoi equivalents?

• To: mathgroup at smc.vnet.net
• Subject: [mg99407] Re: atoi equivalents?
• From: Bill Rowe <readnews at sbcglobal.net>
• Date: Tue, 5 May 2009 05:40:52 -0400 (EDT)

On 5/4/09 at 5:59 AM, michael2718 at gmail.com (Michael) wrote:

>What is the most efficient or recommended way to parse numbers in
>Mathematica?

>I can use ToExpression["1234"] and it will return the number. But
>this won't do, because I could be scraping un-trusted data and the
>above could lead to an injection of code. I could also use something
>like this: ToExpression[StringCases["1234", x1 : NumberString ~~ ___
>-> x1]] but then I have to add error checking and whatnot. I suppose
>I could write a simple MathLink program which implement atoi, atol,
>etc.

>All of these solutions seems like a lot of overhead.  Anybody have a
>better idea?

I really don't see a reason for concern when using ToExpression.
Probably, the simplest way to do what you are trying to do would be

value=ReadList[s=StringToStream["1234"],Number];Close[s]

If the input string is not a number, this code will generate an
error. There is still some overhead. But, any method used to do
input checking will add overhead.