Why do my files get corrupt when i FTP them?

fester

I've been FTPing a load of images recently and i've noticed in a lot of cases that the bottom half of the image would be corrupt (broken up and discolored etc.).

Does this happen anyone else?
Why does it happen?
How do you fix it?

Enygma

You'll need to switch to binary mode when uploading images, usually there's a radio box or a button with 1's and 0's on it. Give it a go anyways.

Mr E

I would say that if binary wasn't switched on, then you wouldn't even see half the image. Most FTP programs use autodetect to determine if its binary or not.

I suggest trying a different FTP program.

- Dave.

mneylon

It has happened to me in the past. Sounds like the transfer wasn't completed properly.
If it's only happened once or twice it could be your connection. If not it's the FTP software you're using

fester

Thanks. It wasn't in binary mode.

So ascii is just for text ehh? Does it transfer more quickly that way?

I was just using command prompt, so thats why it didn't 'auto-detect' which mode to use

Man, you guys are soo brainy and smart

mneylon

Originally posted by fester

So ascii is just for text ehh? Does it transfer more quickly that way?

Text is for ascii files binary is for images etc.
The transfer speed doesn't come into it. If you transfer an image in ascii it'll get corrupted and vice-versa.
A lot of FTP clients have an auto-detect mode, but even that can screw up sometimes if you're using a file format that it isn't sure how to handle.

Snaga

Actually ascii files do get compressed automatically when ftp-ing up and down.

If you have a speed monitor on your ftp application youll notice the speed jump to 12-15K/sec even when your only capable of 4.5-5K/sec on a normal modem. (depends on size of text file and the contents of the file).

It measures the size of the file, checks how long its taking to transfer the file and gives the false speed due to the fact that the data being transfered is less than the data it _thinks_ is being transferred.

This doesnt work with binary files as the compression method doesnt work with all of the 'characters' in the binary file. (So when it is uncompressed at the other end it corrupts the file making the jpeg look all messed up).

There is also no problem sending ascii files as binary, binary mode simply tells the application "Dont use ascii compression on me!!" so an ascii file will take longer to be sent in binary mode than ascii mode.

Enygma

That said, if you're ever uploading .cgi programs written in Perl make sure you upload them in ascii, otherwise they won't work and you'll end up pulling your hair out.