大神求解啊，红色的语句没有时运行正常，但是一旦加进去就输出屯字一大堆

#include<stdio.h>
main()
{
    void openfile();
    FILE *fp;
    char ch,bh;
    char *file="c:\\book\\book.txt";
   
   
    if(!(fp=fopen(file,"r+")))
    {
        printf("open %s is failed",file);
        exit(0);
    }
    openfile(fp);
    printf("please input a string:");
    bh=getchar();
    while(bh!='\n')
    {
        
        fputc(bh,fp);
        bh=getchar();
    }
   
    printf("\n");
    openfile(fp);

    fclose(fp);
   
   
}
void openfile(fp)
{
    char ch;
    ch=fgetc(fp);
    while(ch!=EOF)
    {
        putchar(ch);
        ch=fgetc(fp);
    }
    printf("\n");
}