Answers for ": Could not get lock /var/lib/dpkg/lock-frontend - open (11: Resource temporarily unavailable)"

Could not get lock /var/lib/dpkg/lock-frontend - open (11: Resource temporarily unavailable)

Method 1
ps aux | grep -i apt
sudo kill -9 <process_id>

Method 2

sudo lsof /var/lib/dpkg/lock
sudo lsof /var/lib/apt/lists/lock
sudo lsof /var/cache/apt/archives/lock

sudo kill -9 <process_id>

sudo rm /var/lib/apt/lists/lock
sudo rm /var/cache/apt/archives/lock
sudo rm /var/lib/dpkg/lock

sudo dpkg --configure -a

sudo apt update

E: Could not open lock file /var/lib/dpkg/lock-frontend - open (13: Permission denied) E: Unable to acquire the dpkg frontend lock (/var/lib/dpkg/lock-frontend), are you root?

sudo must be used before and after &&
Example:

sudo apt-get update && sudo apt-get upgrade

E: Could not get lock /var/lib/dpkg/lock-frontend - open (11: Resource temporarily unavailable)

#You can delete the lock file with the following command.
sudo rm /var/lib/apt/lists/lock
#You may also need to delete the lock file in the cache directory
sudo rm /var/cache/apt/archives/lock
sudo rm /var/lib/dpkg/lock

E: Unable to acquire the dpkg frontend lock (/var/lib/dpkg/lock-frontend), are you root?

ps aux | grep -i apt

E: Unable to acquire the dpkg frontend lock (/var/lib/dpkg/lock-frontend), are you root?

$ sudo dpkg --configure -a
dpkg: error: parsing file '/var/lib/dpkg/updates/0004' near line 0:
newline in field name '#padding'