Less common C features supporting systems programming

• systems programming demands speed and consistency
  (compilers can generate very efficient code, and support system-specific function calling conventions)

• close mapping to underlying processor instruction set
  (pre- and post- increment operators, standard string- and memory-based function map to single instructions, pointer dereferencing, pointer arithmetic)

• representation/access to hardware characteristics, fixed-sized data objects
  (well-defined integers of different lengths - 8, 16, 32, and 64 bits)

• permits direct access to process's own memory through pointers