Delete old kernels from Ubuntu

run.sh

#!/bin/sh

# 1. List old versions by:
#  1.1. Listing all "initrd.img-*" files in "/boot" (ls -1), ex: "/boot/initrd.img-5.8.0-44-generic"
#  1.2. Excluding current LOADED version (grep -v), ex: "5.8.0-50-generic"
#  1.3. Extracting version part from listed filenames (awk), ex: "5.8.0-44"
# 2. Purge kernel packages per each version, with confirmation prompt (configmation is enabled by default)
for v in $(ls -1 /boot/initrd.img-* | grep -v `uname -r` | awk -F'-' '{ print $2 "-" $3  }'); do \
  sudo apt-get --purge remove \
    linux-image-$v-generic \
    linux-modules-$v-generic \
    linux-headers-$v \
    linux-headers-$v-generic; \
done