text: // names_st.h -- header file of List_16_7_names_st.c
  // constants
  #include <string.h>
  #define SLEN    32
  // struct declaration
  struct names_st
  {
      char first[SLEN];
      char last[SLEN];
  };
  // type definition
  typedef struct names_st names;
  // function prototypes
  void get_names(names *);
  void show_names(const names *);
  char *s_gets(char *st, int n);