[R] R2.1.0: Bug in list.files

[Thomas Lumley]

On Thu, 12 May 2005, Suresh Krishna wrote:
> Is that the entire story ? I tried this with yesterday's patched version 
> (windows xp) and found:
>
>> list.files(getwd(),"*.txt",full=T)
> Error in list.files(path, pattern, all.files, full.names, recursive) :
>        invalid 'pattern' regular expression
>
>> list.files(getwd(),'.txt',full=T)
> [1] "C:/Documents and Settings/suresh/BDE_SysInfo.txt"
> [2] "C:/Documents and Settings/suresh/dxva_sig.txt"
>
> Replacing "*.txt" with '*.txt' seems to do "something".
>

It finds any file name containing the substring txt beginning anywhere 
except the first letter. Now, this is exactly what *.txt used to do, so in 
that sense it is equivalent, but it probably isn't what you wanted.  The 
pattern argument to list.files isn't a Windows wildcard expression. It 
never has been a Windows wildcard expression.    It just so happens that 
".txt" is also a valid regular expression, but one that means something 
different from the Windows wildcard expression "*.txt".


 	-thomas