Best way to find os name and version in Unix/Linux platform

Question

I need to find the OS name and version on Unix/Linux platform. For this I tried following:

1. lsb_release utility

2. /etc/redha

Answer 1

this command gives you a description of your operating system

cat /etc/os-release

Answer 2

My own take at @kvivek's script, with more easily machine parsable output:

#!/bin/sh
# Outputs OS Name, Version & misc. info in a machine-readable way.
# See also NeoFetch for a more professional and elaborate bash script:
# https://github.com/dylanaraps/neofetch

SEP=","
PRINT_HEADER=false

print_help() {

    echo "`basename $0` - Outputs OS Name, Version & misc. info"
    echo "in a machine-readable way."
    echo
    echo "Usage:"
    echo "    `basename $0` [OPTIONS]"
    echo "Options:"
    echo "    -h, --help           print this help message"
    echo "    -n, --names          print a header line, naming the fields"
    echo "    -s, --separator SEP  overrides the default field-separator ('$SEP') with the supplied one"
}

# parse command-line args
while [ $# -gt 0 ]
do
    arg="$1"
    shift # past switch

    case "${arg}" in
        -h|--help)
            print_help
            exit 0
            ;;
        -n|--names)
            PRINT_HEADER=true
            ;;
        -s|--separator)
            SEP="$1"
            shift # past value
            ;;
        *) # non-/unknown option
            echo "Unknown switch '$arg'" >&2
            print_help
            ;;
    esac
done

OS=`uname -s`
DIST="N/A"
REV=`uname -r`
MACH=`uname -m`
PSUEDONAME="N/A"

GetVersionFromFile()
{
    VERSION=`cat $1 | tr "\n" ' ' | sed s/.*VERSION.*=\ // `
}

if [ "${OS}" = "SunOS" ] ; then
    DIST=Solaris
    DIST_VER=`uname -v`
    # also: cat /etc/release
elif [ "${OS}" = "AIX" ] ; then
    DIST="${OS}"
    DIST_VER=`oslevel -r`
elif [ "${OS}" = "Linux" ] ; then
    if [ -f /etc/redhat-release ] ; then
        DIST='RedHat'
        PSUEDONAME=`sed -e 's/.*\(//' -e 's/\)//' /etc/redhat-release `
        DIST_VER=`sed -e 's/.*release\ //' -e 's/\ .*//' /etc/redhat-release `
    elif [ -f /etc/SuSE-release ] ; then
        DIST=`cat /etc/SuSE-release | tr "\n" ' '| sed s/VERSION.*//`
        DIST_VER=`cat /etc/SuSE-release | tr "\n" ' ' | sed s/.*=\ //`
    elif [ -f /etc/mandrake-release ] ; then
        DIST='Mandrake'
        PSUEDONAME=`sed -e 's/.*\(//' -e 's/\)//' /etc/mandrake-release`
        DIST_VER=`sed -e 's/.*release\ //' -e 's/\ .*//' /etc/mandrake-release`
    elif [ -f /etc/debian_version ] ; then
        DIST="Debian"
        DIST_VER=`cat /etc/debian_version`
    PSUEDONAME=`lsb_release -a 2> /dev/null | grep '^Codename:' | sed -e 's/.*[[:space:]]//'`
    #elif [ -f /etc/gentoo-release ] ; then
        #TODO
    #elif [ -f /etc/slackware-version ] ; then
        #TODO
    elif [ -f /etc/issue ] ; then
        # We use this indirection because /etc/issue may look like
    # "Debian GNU/Linux 10 \n \l"
        ISSUE=`cat /etc/issue`
        ISSUE=`echo -e "${ISSUE}" | head -n 1 | sed -e 's/[[:space:]]\+$//'`
        DIST=`echo -e "${ISSUE}" | sed -e 's/[[:space:]].*//'`
        DIST_VER=`echo -e "${ISSUE}" | sed -e 's/.*[[:space:]]//'`
    fi
    if [ -f /etc/UnitedLinux-release ] ; then
        DIST="${DIST}[`cat /etc/UnitedLinux-release | tr "\n" ' ' | sed s/VERSION.*//`]"
    fi
    # NOTE `sed -e 's/.*(//' -e 's/).*//' /proc/version`
    #      is an option that worked ~ 2010 and earlier
fi

if $PRINT_HEADER
then
    echo "OS${SEP}Distribution${SEP}Distribution-Version${SEP}Pseudo-Name${SEP}Kernel-Revision${SEP}Machine-Architecture"
fi
echo "${OS}${SEP}${DIST}${SEP}${DIST_VER}${SEP}${PSUEDONAME}${SEP}${REV}${SEP}${MACH}"

NOTE: Only tested on Debian 11

Example Runs

No args

osInfo

output:

Linux,Debian,10.0,buster,4.19.0-5-amd64,x86_64

Header with names and custom separator

osInfo --names -s "\t| "

output:

OS  | Distribution  | Distribution-Version  | Pseudo-Name   | Kernel-Revision   | Machine-Architecture
Linux   | Debian    | 10.0  | buster    | 4.19.0-5-amd64    | x86_64

Filtered output

osInfo | awk -e 'BEGIN { FS=","; } { print $2 " " $3 " (" $4 ")" }'

output:

Debian 10.0 (buster)

Answer 3

In every distribute it has difference files so I write most common ones:

---- CentOS Linux distro
`cat /proc/version`
---- Debian Linux distro
`cat /etc/debian_version`
---- Redhat Linux distro
`cat /etc/redhat-release` 
---- Ubuntu Linux distro
`cat /etc/issue`   or   `cat /etc/lsb-release`

in last one /etc/issue didn't exist so I tried the second one and it returned the right answer