You will need to know the exact name of the file you are looking to download, for example: "lnx_drv_celerity8_201.tgz". To find this name, you may need to download it from the support site manually beforehand, and then look at the name of the downloaded file.
Once this is determined, you can download the file using either the "curl -O" or "wget" commands (curl should be available on all systems, while wget will be more rare). Unfortunately, ATTO uses a redirect when attempting to download files from their site, so it's a bit tricky to try and find the true URL for a file manually. However, they all follow the same scheme, so with the filename you gathered, you will have all the information you need.
Below is an example that uses the Celerity 8Gb "201" Linux driver mentioned above:curl -O https://www.atto.com/software/files/drivers/lnx_drv_celerity8_201.tgz
To adapt this to the file you need, keep everything in the command the same up until the last slash, and the simply replace the "lnx_drv_celerity8_201.tgz" filename with the one you need. This should work with all drivers, flash, and ConfigTool downloads.