c语言要改变文件读取位置，会用到rewind语句和fseek语句

rewind语法格式是

rewind(fp)将fp指向的文件读写指针重新指向文件开头

rewind代码示例如下

#include<stdio.h>
int main()
{FILE *fp1,*fp2;char buf[10];int a;fp1=fopen("aaa.txt","r");fp2=fopen("hhh.dat","w");a=fread(buf,1,10,fp1);while(a!=0){fwrite(buf,1,a,fp2);a=fread(buf,1,10,fp1);}fputc('\n',fp2);fputc('\n',fp2);rewind(fp1);a=fread(buf,1,10,fp1);while(a!=0){fwrite(buf,1,a,fp2);a=fread(buf,1,10,fp1);}fclose(fp1);fclose(fp2);return 0;
}

fseek语句语法格式如下

fseek(文件位置，位移量，起始点）

起始点

0表示文件开始的位置

1表示当前读写的位置

2表示文件末尾位置

#include<stdio.h>
int main()
{FILE *fp1,*fp2;char buf[10];int a;fp1=fopen("aaa.txt","r");fp2=fopen("ooo.txt","w");fseek(fp1,10,0);a=fread(buf,1,10,fp1);while(a!=0){fwrite(buf,1,a,fp2);//fseek(fp1,10,1);a=fread(buf,1,10,fp1);}fclose(fp1);fclose(fp2);return 0;
}