Grep searches the named input FILEs (or standard input if no files are named, or the file name –is given) for lines containing a match to the given PATTERN. By default, grep prints the matching lines.
More info can be seen at http://www.tutorialspoint.com/unix_commands/grep.htm
Eg : grep “STRING“ %pathtofile% | cut -d ‘“‘ -f2
Search for a string in a file , the “pipe” connects the
stdout of one command to the
stdin of another , cut with dlimiter ” and select the second term (-f2)