A UNIX Command $ls 1984 2001 2004 2007 2010 TED-talks-grouped-by-year-in-high-quality.metalink 1990 2002 2005 2008 2011 ted_urls 1998 2003 2006 2009 ted_download.sh $cat TED-talks-grouped-by-year-in-high-quality.metalink | grep -w url | wc -l 980 $ UNIX Explanation This command finds out the number of lines with the word “url” in the file TED*.