You can check the file size until it is not changing anymore. Something like:
=adir(aTxtfile, "c:\*.txt")
set comp on
for ia=1 to alen(aTxtFile,1)
cursize=0
do while cursize#fsize(aTxtFile[ia,1])
cursize=fsize(aTxtFile[ia,1])
wait wind time 1.0 "Downloading "+aTxtFile[ia,1]
enddo
* do what you need with this file

endfor

>Hi,
>I have two programs:
>Program1 - Downloads large volume of data from the server to textfiles on the local harddrive. It downloads tfile1, then tfile2 and so on until Tfile5.
>
>Program2 - Operates in a loop. Uses ADIR function to determine if Tfile1 or 2...or 5 is available. If any of them is available it appends data from TfileN to TableN. After data has been appended to Table5 this program terminates.
>
>1.
>But what happens is that in Program2 the ADIR function finds the textfile even before the download is completed. How do I make sure that Program2 begins appending only after the download is complete?
>
>2.
>CAn FoxPro move ahead in code. That is as it is downloading the first text file which is pretty huge will it execute the following lines of code, even if the download is not complete?
>
>Thank you.
>
>Ria.