C fseek()函数

int fseek(FILE *stream, long int offset, int whence)

#include <stdio.h>
void main(){
   FILE *fp;
   fp = fopen("myfile.txt","w+");
   fputs("this is lidihuo", fp);
  
   fseek( fp, 7, SEEK_SET );
   fputs("sonoo jaiswal", fp);
   fclose(fp);
}

this is sonoo jaiswal