If you keep commenting like this, the metadiscussion about comments might become competitively long.
I liked the comments, not because I needed them to help understand what the program is doing (this is a bog standard C program that I think most Unix developers have written several times over) but as document of someone learning C, and as something I can show other people who want to learn C.
I'm a sub-par C programmer and the comments definitely helped me out. Instead of assuming the reader knows what each function does, they are explained in enough detail that the average reader could at least Google for more info based on keywords.
I liked the comments, not because I needed them to help understand what the program is doing (this is a bog standard C program that I think most Unix developers have written several times over) but as document of someone learning C, and as something I can show other people who want to learn C.