How to reach the /etc folder from cd /Macintosh/ HD?

Question

I use Monterey macOS v12.3.

Do you know how can I find the /etc folder from the cd /Macintosh/ HD?

I corrupted my sudoers and I want to modify it from single-user mode, but I am not able to reach the path. I tried the following looking for /etc.

 cd /Macintosh/ HD/System/Volumes/Data
 cd /Macintosh/ HD/System/private

I read this topic, but there was no clue how to reach it: What's /System/Volumes/Data?

Below is the text taken from the currently closed question asked at Stack Overflow.

Title: I corrupted my sudoers file on MAC- how to modify from it from single user mode?

By mistake, I corrupted my sudoers file. I modified it and mis-spelled a word that corrupted the file.

I wrote NOPASSED instead of NOPASSWD.

In the meantime, I am not able to edit it any more.

I am using a MacBook Pro (16-inch, 2021) with macOS 12.3.

I rebooted with single user mode, and opened the Terminal, but I am not able to reach the directory to modify the file.

This log below is from the normal Terminal macOS, not from the single user mode.

oahmed@oahmed-mac /etc % ls -l | grep sudo
-r--r-----   1 root wheel      257 26 Feb 02:05 sudo_lecture
-r--r-----   1 root wheel     1573  2 Feb 12:18 sudoers
drwxr-xr-x   2 root wheel       64 26 Feb 02:05 sudoers.d
oahmed@oahmed-mac /etc % more sudoers
sudoers: Permission denied
oahmed@oahmed-mac /etc % sudo vi sudoers
/etc/sudoers:56:34: syntax error
%admin      ALL = (ALL) NOPASSED: ALL
                             ^
Password:
Sorry, user oahmed is not allowed to execute '/usr/bin/vi sudoers' as root on oahmed-mac.

 

Answer 1

When booting to singe user mode, the following messages can be observed.

To access the /etc directory, read the above and enter the following commands.

/sbin/mount -P 1
/usr/libexec/init_data_protection
/sbin/mount -P 2

Entering ls /etc/sudoers will result in the following.

-sh-3.2# ls /etc/sudoers
/etc/sudoers

As you can see, the name of the volume containing the root directory is irrelevant. In other words, you do not need to enter Macintosh\ HD.

Answer 2

You do not need to boot to single user mode to fix your error. What you need to do is switch your user ID to superuser (root). Under normal unix, the command would be su, however this command will not work as expected until you enable the root user. The procedure is given below.

Enable the root User

Note the lock icon should appear similar to the image shown below.

The steps are given below.

1. Choose Apple menu () > System Preferences, then click Users & Groups (or Accounts).
2. Click the lock icon, then enter an administrator name and password.
3. Click Login Options.
4. Click Join (or Edit).
5. Click Open Directory Utility.
6. Click the lock icon in the Directory Utility window, then enter an administrator name and password.
7. From the menu bar in Directory Utility, choose Edit > Enable Root User, then enter the password that you want to use for the root user.
8. Quit System Preferences. For convenience, leave the Directory Utility window open.

Fix the sudoers File

Proceed with the following steps.

1. Goto a Terminal application window and enter the command su. Enter the root user's password when asked.
2. Once you are the root user, make the necessary correction to the sudoers file.
3. If locked, click the lock icon in the Directory Utility window, then enter an administrator name and password.
4. From the menu bar in Directory Utility, choose Edit > Disable Root User.
5. Quit the Directory Utility.

References

• How to enable the root user on your Mac or change your root password

Answer 3

Using macOS Recovery or a Bootable Installer for macOS

This answer was tested using a bootable installer for macOS 12.0.1 (Build 21A559). You could also boot from macOS Recovery instead.

Here I assume a Terminal window was opened by selecting Utiities > Terminal from the Recovery menubar.

First, I should note that the OP incorrectly entered Macintosh/ HD. Instead, the OP should have used Macintosh\ HD or "Macintosh HD".

Execute the steps given below.

1. Enter the command below to invoke a Z shell. The chroot command changes the root directory to be the same as when booted to macOS Monterey. If you prefer a Bash shell, then substitute bash for zsh.

   Note: If you wish to access any installed third party software, then you may elect to add /usr/local/bin to the PATH variable.

   chroot "/Volumes/Macintosh HD" zsh
   

2. Make the necessary correction to the sudoers file. For example, the command below uses the nano editor to edit the sudoers file.

   nano /etc/sudoers
   

   Note: User GACy20 posted a comment recommending the use of the visudo command.

3. When finished, enter the command below to return to the original Bash shell.

   exit
   

Below is sample output.

-bash-3.2# chroot "/Volumes/Macintosh HD" zsh
root@Mac / # nano /etc/sudoers
root@Mac / # exit
Saving session...shell_session_save:7: read-only file system: /dev/null
...copying shared history...
...saving history...truncating history files...
...completed.
-bash-3.2# 

References

• How to access commands included with macOS from macOS Recovery?
• How to create a bootable installer for macOS
• Mac startup key combinations
• Use macOS Recovery on a Mac with Apple silicon
• Use macOS Recovery on an Intel-based Mac

Answer 4

This series of answers - all from David Anderson (until now) - are treasures for those of us who feel stymied and/or frustrated by Apple's practice of software, systems development & administration.

I add this answer only to augment the information provided in Mr. Anderson's first answer, and perhaps help other users running older versions of macOS. Specifically:

• I still use macOS Catalina (10.15.6) on my machine (because it has been my experience that Apple's upgrades create a larger risk surface for dysfunction).

• In following the procedure for enabling the root user - which I completed successfully thanks to the detailed recipe - I found that upon completion, the su approach remained unavailable to me on my system:

  % su
  Password:
  su: Sorry
  % <repeated several times>
  

  Which seems odd as su is definitely installed on Catalina, and is functional for other users (including Admins). Perhaps this was done in /etc/pam.d/su?

  Instead, I had to resort to this to get the root prompt, which of course is useless for recovery on a Catalina system (maybe others?) if you had made the OP's spelling error:

  % sudo su     # or 'sudo su -' if you prefer
  Password:
  sh-3.2# whoami
  root
  sh-3.2#
  

  ref addenda notes 1. & 2. in the sequel

• The OP asked another question:

  Do you know how can I find the /etc folder from the cd /Macintosh/ HD?
  * Subsequently corrected to cd /Macintosh\ HD

  On my old Catalina system, Macintosh HD appears Under Finder's "Locations", but:

  % cd /Macintosh\ HD
  cd: no such file or directory: /Macintosh HD  
  % cd Macintosh\ HD 
  cd: no such file or directory: Macintosh HD 
  % cd 'Macintosh HD'
  cd: no such file or directory: Macintosh HD
  

  Yet, I can see the contents of Macintosh HD when I click it in the Finder window. I'm sure it's just me: this strikes me as a bit of a disconnect... but not a reason to upgrade :)

  But back to the question at hand, here's what I see when trying to list the contents of the /etc folder on my Catalina system:

  % ls -l /etc
  lrwxr-xr-x@ 1 root  admin  11 Dec  5  2019 /etc -> private/etc
  should this have been '/etc -> /private/etc' ??
  

  However, we can get there like this:

  ~ % cd /etc 
  /etc % ls -l
  total 1072
  -rw-r--r--   1 root  wheel     515 Nov  9  2019 afpovertcp.cfg
  lrwxr-xr-x   1 root  wheel      15 Dec  5  2019 aliases -> postfix/aliases
  -rw-r-----   1 root  wheel   16384 Nov  9  2019 aliases.db
  ...
  /etc %
  

• In closing, wrt editing /private/etc/sudoers (or whatever it's now called), NOTE there is also a folder named :/private/etc/sudoers.d

  sudoers.d is empty on my Catalina system, but it is potentially a great place for adding things like assigning the NOPASSWD option (or NOPASSED if you prefer :) to a user. Note that if you want to create additional rules in sudoers.d, you'll need to include this line in your sudoers file:

  #includedir /etc/sudoers.d

  One should use visudo -f for editing files under sudoers.d - it does the same syntax & "spelling" checks on the entries, but if an entry is added using a conventional editor, it is said that errors will not lock one out of their system. It has other advantages, but I don't know how useful they are for macOS users.

  Always use sudo visudo to edit the sudoers file - regardless of where it's been located on your system. This will avoid the need for an excursion into Single User Mode - especially important if the su command won't get you to the root prompt on your system (e.g. Catalina).

---

The "Addendum/FYI/Not part of the answer section":

Note 1:

I still find it odd that this works even before (and after) the root user was enabled... which beggars the question, "What were they thinking?"

Note 2:

As an aside, for those who are curious about sh:

% sh --version
GNU bash, version 3.2.57(1)-release (x86_64-apple-darwin19)
Copyright (C) 2007 Free Software Foundation, Inc.

:) lol