I created a fairly simple programming exercise for job candidates. It's not trivial, but it's not super hard. Someone who's written programs before and can figure out the solution should be able to write the program in two hours or less. The problem description says "Your program should read from standard input (stdin) and write to standard output (stdout). Sample input and output are available."
I'm rather dismayed by the number of submissions which don't read from standard input or output. The most common violation is using a hard-coded path like C:\input.txt (tip: I'm not running Windows, I don't have a C: drive; even if I did, I wouldn't have the sample input there). Other violations include requiring filenames on the command line (not terrible), prompting for all values interactively in such a way that I can't just run cat input.txt | program, and one submission in PL/SQL that hard-coded the sample input as a bunch of INSERT statements. Tip: I put "use stdin and stdout" in the instructions so that you didn't have to bother with all the file opening and closing details. Also, do they not teach students to run their programs before submitting them? Running a submission on input bundled with the problem shouldn't throw an error before producing any output. Maybe students don't know how to use a command line environment any more and I/O redirection is a foreign concept.
Do today's computer science students really not know what standard input and output are? Do they really have assignments that say "Read this file from C:\Homework\Problem1?" My hope was to create an evaluation script that ran several files through submitted programs and report a correct answer rate. But when correct programs are little more likely to read from stdin, I can't even write a script capable of getting an answer.