Q:

How to identify url in tweet using R

I want to identify those tweets containing URL in my twitter data set. For example, using the sign of "http://".
How to proceed it in R? for example the tweets texts are
  "@RainxDog @twitpic Please HELP #OccupyWallStreet and RT this video: http://t.co/vjwNR7TC"

  "@degamuna Please HELP #OccupyWallStreet and RT this video: http://t.co/vjwNR7TC"

A:

You can use grep
if(length(grep("http://",data))>0){
 data[grep("http://",data)]
}

