kver (aka kernel version) reads a file and looks for a string that looks like a
version, something like \d\d*\.\d\d*\.\d\d*\S*. The first match is returned.
$ kver -kernel /boot/vmlinuz-linux
5.3.0-2-amd64
$ ls /usr/lib/modules
5.3.0-2-amd64
# !!! amazing, it matches !!!
# knowing a particular kernel file,
# scripts can find the corresponding modules
$ for f in /boot/vmlinuz-*; do echo "$f -> $(kver -kernel $f)"; done
/boot/vmlinuz-linux -> 5.4.2-arch1-1
/boot/vmlinuz-linux-hardened -> 5.3.15.a-1-hardened
/boot/vmlinuz-linux-lts -> 4.19.88-1-lts
/boot/vmlinuz-linux-zen -> 5.4.2-zen1-1-zen
kver can also take a string, and then scan installed kernels for this string. It returns the path of the first kernel where the string was found.
$ ls /usr/lib/modules
5.3.0-2-amd64
$ kver -release 5.3.0-2-amd64
/boot/vmlinuz-linux
# !!! amazing !!!
# knowing a particular kernel release,
# scripts can find the corresponding kernel
$ for f in /lib/modules/[0-9]*; do echo "$f -> $(kver -release $(basename $f))"; done
/lib/modules/4.19.88-1-lts -> /boot/vmlinuz-linux-lts
/lib/modules/5.3.15.a-1-hardened -> /boot/vmlinuz-linux-hardened
/lib/modules/5.4.2-arch1-1 -> /boot/vmlinuz-linux
/lib/modules/5.4.2-zen1-1-zen -> /boot/vmlinuz-linux-zen