R devel - Dec 2010 - errors in getconnection or scan

I was wondering if there was a function like "does connection exists"
?
I am currently using loops to build up a database, and I have either
>  B = getConnection(localization)
Error in getConnection(localization) : there is no connection -2147483648
In addition: Warning message:
In getConnection(localization) : NAs introduced by coercion

or
>  B = scan(localization)
Error in file(file, "r") : cannot open the connection
In addition: Warning message:
In file(file, "r") : cannot open: HTTP status was '404 Not
Found'

is there a way to test where localization is an html page, or not ? and to
say that if localization does exist, then scan it ?

	[[alternative HTML version deleted]]

On 13/12/2010 12:36 PM, Arthur Charpentier wrote:
> I was wondering if there was a function like "does connection
exists" ?
See ?showConnections.
> I am currently using loops to build up a database, and I have either
>
>>   B = getConnection(localization)
> Error in getConnection(localization) : there is no connection -2147483648
> In addition: Warning message:
> In getConnection(localization) : NAs introduced by coercion
Where did the localization variable come from?  getConnection is pretty 
rarely used.
>
> or
>
>>   B = scan(localization)
> Error in file(file, "r") : cannot open the connection
> In addition: Warning message:
> In file(file, "r") : cannot open: HTTP status was '404 Not
Found'
>
> is there a way to test where localization is an html page, or not ? and to
> say that if localization does exist, then scan it ?
What's your definition of an html page?  Testing for valid html is hard.

Duncan Murdoch