TCP／IP基础

#include <sys/utsname.h>
#include <unistd.h>
#include <stdio.h>

int main()
{
 union
 {
  short inum;
  char c[sizeof(short)];
 } un;
 struct utsname uts;
 un.inum=0x0102;
 if(uname(&uts)<0)
 {
  printf("Could not get host information ./n");
  return -1;
 }
 printf("%s -%s-%s:/n",uts.machine, uts.sysname, uts.release);
 if(sizeof(short)!=2)
 {
  printf("sizeof short =%d/n", sizeof(short));
  return 0;
 }
 if(un.c[0]==1 && un.c[1]==2)
  printf("big_endian./n");
 else if(un.c[0]==2 && un.c[1]==1)
  printf("little_endian./n");
 else
  printf("unknown ./n");
 return 0;
}