pure human error/stupidity

ok, so Last night i was browsing through finder when i noticed "my name" MacBook Pro under the Shared section, so i clicked it and it showed "Network", "Macintosh HD", and "Users". So I clicked Get Info on the "Macintosh HD" and that indicatewd that my folders weren being shared. But for added Safety/Security I changed the permissions to "System: Full Access", "Users: Write Only (drop box)", and "Everyone: No Access". of course after i rebooted the computer it doesnt boot fully; it hangs at the pinwheel and apple logo, with the pinwheel still spinning. I can access Single-user mode but i need to know if there is a way to reset permissions to default from single user mode, i have already tried safe boot, it angs also.

You will need to change the permission on Macintosh HD back to the original settings.

Owner (system) read & write, group (admin) read & write and others read only

In single user mode check the permissions on the / (root) directory.

ls -ld /

You should see some like the following:

drwxrwxr-t 33 root admin 1224 Jun 20 17:43 /

If not then do the following:

chmod 1775 /

That should set the permission that is listed above. Hopefully after rebooting your system you are okay.

i did what you said in single user mode and it came out with:

drwx-wx--- 39 root admin 1394 Jun 22 09:00

(it used actual hyphens and did not display any alphanumeric characters)

then i did:

chmod 1775 /

and it resulted in:

chmod: /: Read only file system

then rebooted from the "command line" and still takes a while on the pinwheel, dont know yet if it is booted up or not, on a different system.

Try a sudo chmod 1775 /

performed a single user mode boot once again. i noticed this time that it appeared in the text "Root device is mounted read-only".

then performed the following:

:/root# sudo chmod 1775 /

resulted in:

sudo: can't open /private/etc/sudoers: permission denied
:/root# sendmail: warning: valid_hostname: empty hostname
sendmail: fatal: unable to use my own hostname

It appears that you don't have permission to change the file system. The next thing you can try is boot your system with the install media. From there choose the disk utility application from the drop down menu. Click on the repair permissions button. Since your disk is not in use it should correct the problem. After the disk utitlity finishes, quit and reboot your system. If your able to get in, then run disk utility again to repair permission again. This should take care of the what may have change with your latest update of your system.

ok, thanks, i had my dad overnight the install media to me so i should be able to fix the problem sometime tomorrow.

ok. well i tried to do the Repair Permissions from Disk Utility on the install cd and it kept saying Error: An underlying task failed on exit"

Start up from the DVD again and run Repair Disk and see if that fixes the problem, then Repair Permissions as rman suggests.