[linux c]getservbyport|getservbyname

 1 #include <stdio.h>
 2 #include <unistd.h>
 3 #include <netdb.h>
 4 
 5 int main(int argc,char *argv[])
 6 {
 7   struct servent serv;
 8   struct servent *serv_info=&serv;
 9 
10   serv_info=getservbyport(htons(atoi(argv[1])),NULL);/*第二个参数为协议类型，为NULL时自动匹配所有协议*/
11   printf("%s\n%d\n",serv_info->s_name,ntohs(serv_info->s_port));
12   serv_info=getservbyport(htons(atoi(argv[1])),"tcp");
13   printf("%s\n%d\n",serv_info->s_name,ntohs(serv_info->s_port));
14   
15   return 0;
16 
17 }