>>>I tried FREAD instead of FGETS and it looks like it works fine, I tried to read 8192 bytes with FREAD then write them with FWRITE without any modifications and I got same file size.
>>
>>With FREAD some occurences may be split between two sequential reads in which case they will not be replaced.
>
>Not tested, but I wonder if this might be a faster approach?
<snip>

Jim,

The file size is 130MB. :)