text: #include <stdio.h>
  #include <string.h>
  
  void login(void){
  	puts("OK! Login!");
  }
  
  
  int main(void){
  	char buf[20];
  	char name[20];
  
  	printf("Input your name : ");
  	fgets(name,sizeof(name),stdin);
  
  	strcpy(buf,"Hello! ");
  	strncat(buf,name,strlen(name));
  
  	printf("%s",buf);
  
  	return 0;
  }
  