Remove _postgres user safely and completely from Mac /etc/passwd

Question

I'm am attempting to reinstall PostgreSQL as I am unable to log into it at all. I realise I had installed it a long time ago using both the installer from the postgres website and brew install postgres. I have uninstalled both of these now:

• uninstalled using brew uninstall --force postgresql to remove all versions installed via brew.
• uninstalled using sudo /Library/PostgreSQL/9.5/uninstall-postgresql.app/Contents/MacOS/installbuilder.sh
• manually removed /Library/PostgreSQL (rm -rf /Library/PostgreSQL)
• manually the PostgreSQL user (via the Mac Users & Groups).

However I have a _postgres user left in /etc/passwd:

$ grep post /etc/passwd
_postgres:*:216:216:PostgreSQL Server:/var/empty:/usr/bin/false

There are no userdel or usermod commands available on Mac (10.11 El Capitan) and the alternative seems excessively complex (but perhaps necessarily so?)

Answer 1

Use the command brew remove postgresql. Or investigate the uninstall scripts manually.

Edit: Have you tried this?

• Quit Postgres.app & drag it to the Trash

• Delete the data directory (default location: ~/Library/Application Support/Postgres)

• Delete preferences for Postgres.app by executing the following command: defaults delete com.postgresapp.Postgres2

• Remove the $PATH config for the command line tools (optional): sudo rm /etc/paths.d/postgresapp

Edit 2: To delete a user from the command line, boot into single user mode. Hold Command-s at startup. Check the filesystem: /sbin/fsck -fy If no remaining errors, mount the filesystem: /sbin/mount -uw / Start up directory services: launchctl load /System/Library/LaunchDaemons/com.apple.DirectoryServices.plist Note that single user mode said to use com.apple.DirectoryServicesLocal.plist, but that didn't work -- this did. Find what groups the user belongs to: dscl . -list /groups GroupMembership | grep username -- repeat for each group except for the user's own group. Remove the group corresponding to the username: dscl . delete /groups/username (this may not be necessary -- you may get an error that the group doesn't exist; you can ignore it and go on). Remove the user account: dscl . delete /users/username At this point, you may wish to remove or archive the user folder in /Users. You may wish to remove the .AppleSetupDone file in /var/db to cause the Setup Assistant to run when next booted. Type reboot to reboot the system or shutdown -h now to shut down the system.