def substitute(f,g,w,x) `sed s/#{w}/#{x}/g < #{f} > #{g}` end

Xan Xann wrote:
> Hi,
> 
> Can anyone help me in that?
> I just want to write the following function:
> 
> substitute(f,g,w,x)
> 
> where f and g are files and w and x are strings
> That function substitutes all the ocurrences of w in the file f and 
> writes x to g
> 
> For example, if f is:
> "
> Hello folks or
>  old men
> "
> 
> and w = "ol" and x="ur"
> 
> then g is:
> 
> "
> Hello furks or
>  urd men
> "
> 
> Can anyone show me some code?
> I thinked to pass file to string but I thinked it was not very fast. 
> Better directly
>