Upload a file to Hadoop DFS To upload a file (e.g. purchases.txt) to the hadoop DFS, use the following command: $hadoop fs -put purchases.txt myinput This will upload the file "purchases.txt" to Hadoop DFS within the directory named "myinput" List files in Hadoop DFS To list files in Hadoop DFS, use the following command: $hadoop fs -ls This will list the files in Hadoop DFS To list files in "myinput", use the following command: $hadoop fs -ls myinput Process file in Hadoop DFS using mapper and reducer programs To process data in files uploaded to Hadoop DFS via mapper and reducer programs, use the following commad: $hadoop jar [hadoop.jar location_path] -mapper mapper.py -reducer reducer.py -file mapper.py -file reducer.py -input myinput -output joboutput Where [hadoop.jar location_path] is the path to the hadoop jar file; mapper.py is the mapper python program, and reducer.py is the reducer python program, "myinput" is the input to mapper.py, a...