C语言：读写TXT

fopen() 改为： if((fp=fopen("1s.txt","w+"))==NULL)

fputc(p,fp); 改为：fprintf(fp,"%d",p); 
读语句前，加一句文件回绕到文件头： rewind(fp); 

#include <stdio.h>
main()
{
    FILE *fp;
    char read[1000];
    char s;
    long p;
    if((fp=fopen("1s.txt","w+"))==NULL)
    {
        printf("\nOpen file error!press any key exit!");
        getchar();
        //exit(0);
    }
    p=123457;
    s='\n';
    fprintf(fp,"%d",p);
    fputc(s,fp);
    fprintf(fp,"%d",p);
    rewind(fp);
    fgets(read,1000,fp);
    printf("%s",read);
    system("pause");
    return 0;
    }