Extract/print app version number (separated by dots) out of a string on Linux

[Fli]

This Linux command should work to extract first occurrence of a version number out of a string.

command:

echo "airdcpp_2.12.2_webui-2.12.1_64-bit_portable.tar.gz" | grep -oP '\d+(\.\d+)*' | head -n 1

returns:
2.12.2

To return version of some Debian/Ubuntu package, this may work:

dpkg -s nicotine | grep '^Version:' | awk '{print $2}' | awk -F'-' '{print $1}'

awk after the last pipe splits the version string on the hyphen (-) and prints the first part, effectively removing any subversion