If you give a better description of what you really want to achieve, we can help you better.

You don't only want to search a file, you also want to write it back, which is new information. And when you write it back, is it to the same file name, or a new?

Also, please tell us roughly how big the files are.

The more information you give, the better.

>On slow computers when I issue FILETOSTR(), then some proccesing and then STRTOFILE() back, sometimes error file access denied occurs. I don't want to slow down program while proccesing because of few users :-(. So, I'm looking for a possible different solution.
>
>May I ask what's wrong with using FileToStr()?
>
>>Line lenght can be more than 254 bytes and before the time of proccesing I don't know lenght of a specific line.
>>
>>You can use FGET to read text file line by line and compare
>>
>>>Any ideas how to find string between two unique strings in TXT file without using FILETOSTR command?
>>>For example I need to find string
>>>
>>>aa
>>>bb
>>>cc
>>>
>>>in TXT file
>>>
>>>1111
>>>2222
>>>3333
>>>first string:aa
>>>bb
>>>cc
>>>second string:fsdfsdfs
>>>444
>>>555