End Google Ads 201810 - BS.net 01 --> Hello everybody !

I don't want to read the Text File,because the file is too large.

example , if the text file only have this characters ,like "12356789".

when I user this C++ code ,it will cover the old data.

FILE *pFile = fopen("1.txt","w");
fseek(pFile,3,SEEK_SET);
fwrite("4",1,strlen("4"),pFile);
fclose(pFile);

How to insert the character '4' into the text file ?

thanks for your reply !

Best Reguards !