Classwork 11

Logistics

• Due: Wednesday, March 1st AoE.
• Submission instructions: make sure that the required file (read_file.c) is in your /classwork/week7/wed/ directory.
• Deadline reminder: after the deadline passes, you cannot earn any points for this assignment.

Learning outcomes

• Practice reading and writing using a file pointer in C.

Assignment

• Log in to the server.
• From your home directory, navigate to classwork/week7/wed/, creating directories week7 and wed if necessary.
• Create a file called read_file.c, and inside it write a C program that does the following:

Use fopen to open the file /public/classwork/week7/wed/input.txt, read the doubles it contains, and print their maximum value to a file called max.txt in the same directory as your read_file.c file. You should also use fopen to read the file you are writing to. You can assume that the input file contains exactly 5 doubles.

Hints

• You can check that you will get full credit for this assignment by compiling your program, running it and saving its output to a file, and comparing that file to the example output. Specifically, do:

  gcc -o exe -Wall read_file.c
  ./exe
  diff -w -i ~/classwork/week7/wed/max.txt /public/classwork/week7/wed/expected_output.txt
  

  You will see any warnings during compilation and any differences between your output and the expected output on the screen. If nothing happens, the content of your output file exactly matches the expected content and there were no warnings when compiling. As long as your file is in the correct place and named correctly, this means that you will get full credit for the assignment.

Grading turnaround

Everyone gets a point for this one!

Preliminary results via autograder will be present in the appropriate classwork directory in the autograder.txt, refreshed every 2 minutes from 8am to 11am on the class day, and then every hour until 6am the following day. The 6am run is the final grade. Scores will be uploaded to D2L by the next class period.