Problem with compare two large text file

[Thanh Ly]

I am wondering is there a way or different method to compare two large text file without taking up so much time. I tried the FC.exe command and it did it very fast, but when I try to compare it in my VB program, it takes forever to finish with following code.

open FN1 for input as #1
while not eof(1)
line input #1, Str1
open FN2 for input as #2
do while not eof(2)
line input #2, Str2
if (Str1 = Str2) then
bfound = true
exit do
end if
loop
wend

Thanks you in advance

[Andrew R.]

First of all I would remove opening statement from the loop.

[Iouri]

Try to compare in binary mode. It must speed it up

'Description: Compares the content of two files

Open "file1" For Binary As #1
Open "file2" For Binary As #2
issame% = True
If LOF(1) <> LOF(2) Then
issame% = False
Else
whole& = LOF(1) \ 10000 'number of whole 10,000 byte chunks
part& = LOF(1) Mod 10000 'remaining bytes at end of file
buffer1$ = String$(10000, 0)
buffer2$ = String$(10000, 0)
start& = 1
For x& = 1 To whole& 'this for-next loop will get 10,000
Get #1, start&, buffer1$ 'byte chunks at a time.
Get #2, start&, buffer2$
If buffer1$ <> buffer2$ Then
issame% = False
Exit For
End If
start& = start& + 10000
Next
buffer1$ = String$(part&, 0)
buffer2$ = String$(part&, 0)
Get #1, start&, buffer1$ 'get the remaining bytes at the end
Get #2, start&, buffer2$ 'get the remaining bytes at the end
If buffer1$ <> buffer2$ Then issame% = False
End If
Close
If issame% Then
MsgBox "Files are identical", 64, "Info"
Else
MsgBox "Files are NOT identical", 16, "Info"
End If

Iouri Boutchkine
[email protected]