Copying a file from a range of bytes....

[privoli]

Dear all,

Making a program to copy a file to another file but only the specified range of bytes. IE: The first 4500k of a 10mb file etc... I've fiddled with some code, works fine, but rus extremely slow, im talking, 5 minutes to copy 1000k of data, anyone know of a more efficient way to copy a file using byte range, here's my code...

Dim TempChar as Byte
Dim ByteLength as Long

Open "input.dat" for Binary Access Read as #1
Open "output.dat" for Binary Access Write as #2

ByteLength = 4539139 'End of file or byte length, just over 4.5mb of the file

'from start of file to end of marker/byte length...
For x = 1 to ByteLength
    Get #1,, TempChar
    Put #2,, TempChar
Next x

Close #1
Close #2

Anyone know why it takes so god damn long to do something simple? its using on average of %6 CPU usage the rest is idle, therefore it aint the CPU causing probs. please help!

it is slow because the string is very long. speed is not directly relative to string length, try using several smaller strings, not more than 3000 characters at a time.

[kedaman]

Ok, loading a varlen string is much faster, aslo use freefile so that you don't get invalid filenumbers

Dim Temp as string
Dim ByteLength as Long
f1=freefile
Open "input.dat" for Binary Access Read as f1
f2=freefile
Open "output.dat" for Binary Access Write as f2

    Get f1,, Temp
    Put f2,, Temp

Close f1
Close f2