[R] Regular expression problem

[jim holtman]

try:

> grep("n.*mytype",mystr)
[1] 1


with the [.] it is a class with a period.  '.*' match zero, or more, characters.

On Tue, Sep 15, 2009 at 5:52 PM, Sebastien Bihorel
<sebastien.bihorel at cognigencorp.com> wrote:
> Dear R-users,
>
> I am trying to use the grep function to test whether a particular string is
> of the form "n.../mydir/myfile.mytype.myext". Anything between n and mytype
> could vary, and anything after mytype could vary. I tried to proceed by
> steps to build my regular expression... but I do not really understand why
> the last call of the following code do not work.
>
> Any help would be greatly appreciated.
>
> mystr <- "n.../mydir/myfile.mytype.myext"
>
> grep("mytype",mystr)
> # returns 1
>
> grep("[.]*mytype",mystr)
> # returns 1
>
> grep("n[.]*mytype",mystr)
> # returns integer(0)
>
>
> Sebastien
>
> ______________________________________________
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> and provide commented, minimal, self-contained, reproducible code.
>



-- 
Jim Holtman
Cincinnati, OH
+1 513 646 9390

What is the problem that you are trying to solve?