Switch to /etc/os-release to get system info

[Photon89]

The currently used /etc/issue seems to be less suiting (only gives \S{PRETTY_NAME} \r (\l) for me on Manjaro).

With /etc/os-release we would get

NAME="Manjaro Linux"
BUILD_ID=rolling

[DarthGandalf]

What are these magic numbers?

[Photon89]

They grab the 1st and 5th line in the file. The complete file looks like this for me:

NAME="Manjaro Linux"
PRETTY_NAME="Manjaro Linux"
ID=manjaro
ID_LIKE=arch
BUILD_ID=rolling
ANSI_COLOR="32;1;24;144;200"
HOME_URL="https://manjaro.org/"
DOCUMENTATION_URL="https://wiki.manjaro.org/"
SUPPORT_URL="https://forum.manjaro.org/"
BUG_REPORT_URL="https://manjaro.org/help/"
PRIVACY_POLICY_URL="https://manjaro.org/privacy-policy/"
LOGO=manjarolinux

[DarthGandalf]

Please treat this file as key/value pairs instead of counting which line is on which position.

NAME=Gentoo
ID=gentoo
PRETTY_NAME="Gentoo Linux"
ANSI_COLOR="1;32"
HOME_URL="https://www.gentoo.org/"
SUPPORT_URL="https://www.gentoo.org/support/"
BUG_REPORT_URL="https://bugs.gentoo.org/"
VERSION_ID="2.18"

[Photon89]

Do you happen to know a bash tool which can read a file this way?

[DarthGandalf]

Come on, this is perl, which is designed for text processing. Why do you need bash or other external tools?

I printed the NAME, feel free to adjust

[vadi2]

Not everyone is a perl expert :)

[Photon89]

Absolutely, this code is way over my level! 🥲

[Photon89]

I added version/build ID info. As far as I understand, only one of the variables is set in /etc/os-release, so putting both of them into the output string will give a nice output including only the one provided.

In my case I get "Manjaro Linux rolling".

[DarthGandalf]

What happens if both are set?

There's no guarantee which of them should be set

[Photon89]

What happens if both are set?

Then we get something like "Distro 1.23rolling". So there is no space character between version and build ID. But if we add a space character, there will be two of them in "Distro rolling".

[DarthGandalf]

 			my %map = map {
				chomp;
				my ($key, $value) = split /=/, $_, 2;
				$value =~ s/^(['"])(.*)\1$/$2/;
				($key, $value)
			} <$fh>;

<$fh> reads the file line by line, and executes the block in map{} for each line, setting $_ to the line.
chomp removes \n from the end of $_
split finds first = and produces array of at most "2" elements - to the left of first = and to the right of it; then elements of these array are assigned to 2 vars.
Then s/// removes quotes from start and end of the value, where the starting quote needs to match the ending quote - both are ether ' or ".
The return value of map block is array of 2 elements, so they are concatenated to one long array key1/value1/key2/value2/etc, but it's assigned to %map, which takes the elements pairwise and understands first of each pair to be the key and second the value.

			local $, = ' ';
			say grep { $_ } map { $map{$_} } qw/NAME VERSION_ID BUILD_ID/;

qw// is same as ("NAME", "VERSION_ID", "..."), just spelled more compactly, this is idiomatic perl for array of strings.
map function turns it into array of values, by looking up each key in %map; during lookup in the %map the sigil becomes $ instead
Then grep function takes the array of values, and removes values which are falsy
Then say function prints the array to stdout, using $, as separator between elements
local is how such special vars are normally temporarily modified - the value of the var will revert to previous value when this statement goes out of scope.

[Photon89]

Sounds like magic! 😄

I tested the latest commit, it produces a nice output on my machine. Unfortunately, I can't approve because I created this PR.