HD Not Accessible to Repair Permissions

Question

Hello. I hope you can help me isolate the error that is keeping my Intel iMac G5 from booting properly. I’m running 10.4.
It froze after I’d been backing up onto DVD/dumping old data (about 20GB worth). Whenever I tried restarting the screen would freeze on the grey apple logo, sometimes with the swirly icon.
When I ran Disk Utility off the install disk at first it indicated “error detected” on mass storage, but later said it was fine. But I could not run Repair successfully (I kept getting "repair failed" messages), and the Repair Disk Permissions button was not accessible (greyed out).
I could not startup in safe mode. And if I tried to restart in DU the only option was a Network (which I'm not hooked up to).
Once I got a Kernal panic screen but most of the time it was just a grey apple with the fan hitting 900 rpm.
Finally I ran DiskWarrior and in 15 minutes it had cleaned out and rebuilt my HD. I thought I was home clear.
However, even though Disk Utility now says my HD is fine, it still does not allow me to Repair Disk Permissions - the option is greyed out. And if I boot up pressing Option to select a Startup Disk, the rebuilt drive is not one of them.
It appears my /Library/Receipts folder is empty.
What’s more, if I try to run an admin command in Terminal, like
sudo diskutil repairPermissions /
I get the message:
-bash: sudo: command not found
In fact, any way I try typing sudo I get a “command not found” message, even if I try to run other command like chmod.
When I type:
Users
I get
Users: command not found.
So I typed:
Echo $PATH
And get
/bin:/sbin:/usr/bn:/usr/sbin:/usr/libexec:/System/Library/CoreServices
I’m not sure at this point whether the fact that the DiskWarrior-rebuilt drive doesn’t show up among Startup options (when I boot with option key) is because of missing/broken permissions; an empty /Library/Receipts folder; missing users; or a missing path.
Any and all help is appreciated. Thank you.

Answer 1

Oy. I purchased an external drive and began installing Mac OSX onto it, so that I could then migrate all files from the unbootable hard drive before running an Archive & Install. That part seemed to go smoothly. But a few problems have emerged:
1. Though I was prompted to keep Disk 2 of the install ready, it never asked me for it, even though I ran the installation 2 or 3 times. Consequently while I can select the external drive when booting up command-S, I can only see Install window, Disk Utility or Terminal windows - never a desktop, preferences drop down, help menu, finder, all the things I'd typically see when launching my machine. Is this normal? Is there a way to force it to install only disk 2 if it has things it needs for full bootable GUI / access?
2. Booting up with the install disk, in disk utility I can see both drives but still cannot repair permissions on my affected HD. I tried via Terminal (repairPermissions, chmod or chown) commands; I keep getting error messages (command not found).
3. Switching cd / to my new drive in Terminal, I was able, I think, to change permissions (755) but when I open Disk Utility the drive is still not writable and "Repair Disk Permissions" is still grayed out.
4. I could not open Migration Assistant on the new drive via Disk Utility, so I copied it from the HD into its own folder on the new one, but am really confused about the whole Disk Image thing. If I create a new disk image and try to open it, convert or checksum it, it still is grayed out, I can never just open it. I tried running commands in Terminal to run that application on the external drive, pointing to the new folder, to the .app, to the contents, .dmg, and no commands seem to work, I keep getting the command not found message.
If I just run the A&I, I fear I'll lose my data which is why I wanted to migrate everything over before I did so. But if the user / owner permissions are screwed up and the only way to fix them is A&I, I don't know what else to do.
Is there ANY way to boot from the install, run Migration Assistant from the external drive (either through Disk Utility or Terminal) and copy all files from HD? If not, I guess I'll have to cross fingers and A&I.
Gee, I used to love my Mac ...