>(VFP 7 SP1 on Windows 2000 or Windows XP pro)
>
>I have to perform 3 operation on a text file.
>
>1 - read a line from a text file.
>2 - perform some operations on the string.
>3 - write the line in another file.
>
>The text file was really big (950 mb).
>
>The program run fast for the first ~50 mb but after that it start to slow down (crawl).
>The computer have 1 gb of memory an 100 gb of available disk space.
>From the task manager I can see that only around 200 mb was used during the operation.
>
>What is the best way to open the files? buffered/unbuffered?
>Flush when I reach a certain point in the file? every 10 mb?
>How can I optimize the process to use all available memory and speed up the process? some sys() function to use?
>
>TIA :-)

I never heard that such a problem existed.

How about re-opening the file every 1 MB or so? Before closing, you would have to save the current position, and then restore it later.

HTH, Hilmar.