Could not get lock /var/lib/dpkg/lock-frontend. It is held by process 2192 (apt-get) code example

Example 1: E: Unable to acquire the dpkg frontend lock (/var/lib/dpkg/lock-frontend), are you root?

ps aux | grep -i apt

Example 2: 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'