My copy of K&R is buried in a box somewhere, so I had to go hunting for a basic C language reference. The first thing that popped up on a Google search for “c language reference” was The C Library Reference Guide.
I may just leave K&R buried in that box. This is an excellent reference, and far quicker to use, even though my copy of The C Programming Language is dogeared and falls open to the printf page when I lay it on a flat surface.