#!/bin/bash
# Script zur Ausgabe der Betriebssystemen von Linux-Servern
# Vorrausgesetzt sind:
# 1. eine Liste der Server in der Datei hosts.txt
# 2. befüllte ~/.ssh/config

get_os_info() {
    local host=$1
    
    result=$(ssh -o ConnectTimeout=5 -o BatchMode=yes "$host" '
        if [ -f /etc/os-release ]; then
            . /etc/os-release
            echo "$NAME|$VERSION_ID|$(uname -r)"
        elif [ -f /etc/redhat-release ]; then
            echo "$(cat /etc/redhat-release)|unknown|$(uname -r)"
        elif [ -f /etc/debian_version ]; then
            echo "Debian|$(cat /etc/debian_version)|$(uname -r)"
        else
            echo "$(uname -s)|unknown|$(uname -r)"
        fi
    ' 2>/dev/null)
    
    if [ $? -eq 0 ]; then
        echo "$host|$result"
    else
        echo "$host|CONNECTION_FAILED|-|-"
    fi
}

if [ ! -f "hosts.txt" ]; then
    echo "ERROR: hosts.txt nicht gefunden!" >&2
    exit 1
fi

echo "Server|OS|Version|Kernel"

echo "# Lese hosts.txt..." >&2

while read -r line; do
    [[ -z "$line" ]] && continue
    [[ "$line" =~ ^# ]] && continue
    [[ "$line" =~ ^[[:space:]]*$ ]] && continue
    
    get_os_info "$line"
done < hosts.txt