程序代码：

#include<stdio.h>
#include<stdlib.h>
void main()
{
    FILE *fp;
    char ch,filename[10];
    scanf("%s",filename);
    if((fp=fopen(filename,"w"))==NULL)
    {
        printf("Error\n");
        exit(0);
    }
    ch=getchar();
    ch=getchar( );
    while(ch!='1')
    {
        fputc(ch,fp);
        putchar(ch);
    }
    putchar(10);
    fclose(fp);
}

程序代码：

while(ch!='1')
{
    fputc(ch,fp);
    putchar(ch);
    ch = getchar();
}