String operations
  strcmp(...)
  strcpy(...)
  strcat(...)

Memory operations
  memcpy(...)
  memmove(...)
  memset(...)

Preprocessor directives
  #define VALUE contstant
  #define ACTION { statements }
  #define PLUS1( x ) ( ( x ) + 1 )
  #include ....
  #if .. #ifdef .. #ifndef .. #else .. #elif .. #endif