程序代码：

#include<stdio.h>
#include<stdlib.h>
struct stud
{

    long num;

    char name[20];

    struct stud * next;    
};


void new_stud();
void listall();
struct stud *head,*cur,*newp;
int main(char argc,char** argv )
{
    char ch;
    int isClose=1;
    head=NULL;
    while(isClose)
    {
        printf("\n type 'E' or 'e' to enter new student,");
        printf("\n type 'L' or 'l' to list all students:");
        ch=getchar();
        getchar();     /*这个getchar() 有什么作用~？*/
        switch(ch)
        {
            case 'e':
            case 'E':new_stud();break;
            case 'l':
            case 'L':listall();break;
            default:isClose=0;
        };
    }

    return 0;
}

void new_stud()
{
    char numstr[20];
    newp=(struct stud *)malloc(sizeof(struct stud));
    if(head==NULL)
    {
        head=newp;
    }    
    else
    {

        while(cur->next!=NULL)
        {
            cur=cur->next;
        }    
        cur->next=newp;
    }
    cur=newp;
    printf("\n enter NO.:");
    gets(numstr);
    cur->num=atol(numstr);
    printf("\n enter name:");
    gets(cur->name);
    cur->next=NULL;
}

void listall()
{
    int i=0;
    if(head==NULL)
    {
        printf("\n No Student!");
        return;
    }
    cur=head;
    for(;cur!=NULL;)

    {
        printf("\n=============================");
        printf("\n Num:  %ld",cur->num);
        printf("\n Name: %s",cur->name);
        printf("\n------------------------");
        cur=cur->next;
    }

}