R help - Mar 2010 - single quotes and double quotes in a system() command. What to do?

Hi all,

I would like to run the following from within R:

awk '{$3=$4="";gsub("  ","");print}'
myfile > outfile

However, this obviously won't work:
system("awk '{$3=$4="";gsub(" 
","");print}' myfile > outfile")

and this won't either:
system("awk '{$3=$4='';gsub(' 
','');print}' myfile > outfile")


Can anyone help me out? I'm sure there's an obvious solution. Thanks,

Matt


-- 
Matthew C Keller
Asst. Professor of Psychology
University of Colorado at Boulder
www.matthewckeller.com

On 29/03/2010 5:14 PM, Matthew Keller wrote:
> Hi all,
> 
> I would like to run the following from within R:
> 
> awk '{$3=$4="";gsub("  ","");print}'
myfile > outfile
> 
> However, this obviously won't work:
> system("awk '{$3=$4="";gsub(" 
","");print}' myfile > outfile")
> 
> and this won't either:
> system("awk '{$3=$4='';gsub(' 
','');print}' myfile > outfile")
> 
> 
> Can anyone help me out? I'm sure there's an obvious solution.
Thanks,
Escape the quotes that match the ones you use in R:

system("awk '{$3=$4=\"\";gsub(\" 
\",\"\");print}' myfile > outfile")

or

system('awk \'{$3=$4="";gsub(" 
","");print}\' myfile > outfile')

Duncan Murdoch