{HEAD ~ The basic file system operations} are searching for a file within {TAIL ~ a directory}, reading from a file, and writing to a file 
{ HEAD ~ The basic file system operations } are searching for a file within { TAIL ~ a directory } , reading from a file , and writing to a file
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH