Check distro using $BASH

check-distro.sh

#!/usr/bin/env bash
# return an awkable string consisting of
#    unix OS type, or
#    Linux dist, or
#    a long guess (based on /proc), or
#    no clue

giveUp () {
	echo "Unknown"
	exit 0
}

# keep this easily awkable, prepending an initial clue
versionGuess () {
	if [ -e /proc/version ]; then
		echo -n "Unsure "
		cat /proc/version
		exit 0
	fi
	return 1
}

# if we have ignition, print and exit
gotDist () {
	[ -n "$1" ] && echo "$1" && exit 0
}

# we are only interested in a single word "dist" here
# various malformations can occur; admin will have to code appropately based on output
linuxRelease () {
	if [ -r /etc/lsb-release ]; then
		dist=$(grep 'DISTRIB_ID' /etc/lsb-release | sed 's/DISTRIB_ID=//' | head -1)
		gotDist "$dist"
	fi

	dist=$(find /etc/ -maxdepth 1 -name '*release' 2> /dev/null | sed 's/\/etc\///' | sed 's/-release//' | head -1)
	gotDist "$dist"

	dist=$(find /etc/ -maxdepth 1 -name '*version' 2> /dev/null | sed 's/\/etc\///' | sed 's/-version//' | head -1)
	gotDist "$dist"

	return 1
}

# start with uname and branch the decision from there
dist=$(uname -s 2> /dev/null)
if [ "$dist" = "Linux" ]; then
	linuxRelease
	versionGuess
	giveUp
elif [ -n "$dist" ]; then
	echo "$dist"
	exit 0
else
	versionGuess
	giveUp
fi

# we shouldn't get here
giveUp
# done