Formatting output from awk command in script

Question

If I run this command:

awk -F'[="]+' '/^(NAME|VERSION)=/{printf("%-17s: %s\n",$1,$2)}' /etc/os-release

from a terminal, I can retrieve this:

NAME             : Debian GNU/Linux
VERSION          : 8 (jessie)

(note the formatting/spacing). However, when I try to assign this command to a local variable and call it, as I do in this function:

#!/bin/bash 

#### Display header message ####
# $1 - message

function write_header(){
    local h="$@"
    echo "------------------------------"
    echo "  ${h}"
    echo "------------------------------"
}

#### Get info about Operating System ####

function  os_info(){
    local namevers=$(awk -F'[="]+' '/^(NAME|VERSION)=/{printf("%-17s:    %s\n",$1,$2)}' /etc/os-release)
    write_header "System Info"
    echo "Operating System : $(uname --kernel-name)"               
    echo "Kernel Version   : $(uname --kernel-release)"             
    echo $namevers     
}

os_info

My formatting get's mangled (see output after NAME):

------------------------------
System Info
------------------------------
Operating System : Linux
Kernel Version   : 3.16.0-4-amd64
NAME : Debian GNU/Linux VERSION : 8 (jessie)

I can work around the formatting error by getting rid of the local variable, and calling awk on individual lines like this:

awk -F'[="]+' '/^(NAME)=/{printf("%-17s: %s\n",$1,$2)}'    /etc/os-release
awk -F'[="]+' '/^(VERSION)=/{printf("%-17s: %s\n",$1,$2)}' /etc/os-release

but that looks a little clunky, and doesn't follow the structure of the larger script I am writing. Any suggestions on how to fix this?

Please note: I can't use the LSB module because some machines I am testing this script on don't have that package installed. Also, things need to run without elevated privileges.

Answer 1

Ah, I see the problem in the script:

The variable is being split here:

echo $namevers

To fix it, do:

printf '%s\n' "$namevers"

Here's the output:

------------------------------
    System Info
------------------------------
Operating System : Linux
Kernel Version   : 3.16.0-4-amd64
NAME             : Debian GNU/Linux
VERSION          : 8 (jessie)

Answer 2

If I've understood correctly, this should produce the output you're after:

function  os_info(){
    write_header "System Info"
    echo "Operating System : $(uname --kernel-name)"               
    echo "Kernel Version   : $(uname --kernel-release)"             
    awk -F'[="]+' '/^(NAME|VERSION)=/{printf("%-17s:    %s\n",$1,$2)}' /etc/os-release
}

If you really want to use a variable, you need to quote it to preserve the formatting:

echo "${namevers}"

Answer 3

While this answer may not answer your question directly concerning the awkkung-fu, you also could just source the /etc/os-release and use the variables right away.

function  os_info() {
    . /etc/os-release
    write_header "System Info"
    echo "Operating System : $(uname --kernel-name)"               
    echo "Kernel Version   : $(uname --kernel-release)"             
    echo "NAME             : $NAME"
    echo "VERSION          : $VERSION"
}