In the image you provided, the
pset1 directory in the directory tree to the left of the IDE is collapsed--notice how the arrow is pointing to the directory's folder and not down, as the arrow next to your home directory (
~/) does. All of the files you see in the directory tree are currently in your home directory and not in
~/psetl/hello, which is empty probably based on
ls not providing any output. You could get a better idea if there is anything in the directory, including hidden, files by running
ls -al, which will provide output, even if the only options in the directory are to go back to the parent directory (
I see that you have a filed already in your home directory called
hello.c. You can move this to the correct directory by typing
mv ~/hello.c ~/pset1/hello into your terminal, or creating a new file in the correct directory by typing
touch ~/pset1/hello/hello.c. I have included full paths for these commands so that they work no matter what directory you execute them in.
Once you have the files in the correct directories, you should be able to use the commands that are shown in the problem specification.
Hope this helps and let me know if you have any issues.