Hardware test...

OK, that was it. I had been knocking my head against the wall for almost a week and it was such a simple thing. Thanks.

sudo bless --folder "/Volumes/iMac AHT/System/Library/CoreServices/.diagnostics" --file "/Volumes/iMac AHT/System/Library/CoreServices/.diagnostics/diags.efi"

I was thinking that, since there weren't quotes directly around iMac AHT, the space needed to be escaped. Didn't realize that the quotes around the entire thing took care of that. Btw, what is the purpose of the quotes around those two entire lines?

WZZZ wrote:

Btw, what is the purpose of the quotes around those two entire lines?

Huh? In your command…?

sudo bless --folder "/Volumes/iMac AHT/System/Library/CoreServices/.diagnostics" --file "/Volumes/iMac AHT/System/Library/CoreServices/.diagnostics/diags.efi"

There are no quotes over the 2 lines, it's all one line too 🙂

I'm not sure I understand what you mean?

1. All the bless commands I've seen have enclosing quotes around the entire line (two sets of quotes around the entire two lines that are separated by --file), not just around the volume name; is that done just as a precaution in case the volume name has spaces? and 2. For those bless commands, why isn't it sufficient just to suggest putting quotes around the volume name, if and only if the volume name has spaces?

In other words, would this command have worked equally well:

sudo bless --folder /Volumes/"iMac AHT"/System/Library/CoreServices/.diagnostics" --file /Volumes/"iMac AHT"/System/Library/CoreServices/.diagnostics/diags.efi"

Instead of

sudo bless --folder "/Volumes/iMac AHT/System/Library/CoreServices/.diagnostics" --file "/Volumes/iMac AHT/System/Library/CoreServices/.diagnostics/diags.efi"

My question was really are those quotes necessary around the entire two lines that are separated by --file? Are they doing anything other than escaping the space in the volume name? It seemed like they were doing something other than that.

Wrapping the whole line would escape everything enclosed, it seems to work OK. I haven't seen reasons for quoting the command & the argument flags like that, it seems unusual to me but it does work 🙂

Double quotes lead to the contents being interpolated or expanded in the shell. You can use single quotes if you want to avoid it & pass a literal value that will 'stay literal'. That would fail if you wrap the whole line in single quotes.

You are right, the disk name could be quoted or you could quote just the spaces too…

sudo bless --folder /Volumes/iMac" "AHT/System/Library/CoreServices/.diagnostics --file /Volumes/iMac" "AHT/System/Library/CoreServices/.diagnostics/diags.efi

It doesn't really matter so long as the right characters are passed, the trouble is knowing which ones to escape or quote, I tend to escape manually when testing then use double quotes in scripts.

Did you get the Mac to boot from AHT?

Interesting, never came across inserting double quotes inside the space that needs to be escaped. The Mac booted to the AHT right away from Option/Alt (think it got renamed "boot.efi"). Didn't run it; just keeping it around (along with the real deal ASD for this Mac) in case the optical drive ever gets funky.

Hi again!

I downloaded the AHT file again and used it without converting, and it worked great!

Thanks a lot!

Sorry, I haven't been checking this site & missed your earlier post.

It's unclear what caused the error but I haven't tested on 10.12 so if you managed to get it working that is good news.