version-compare

#!/usr/bin/env sh
# Version comparison utility (replacement for dpkg --compare-versions)
# Usage: version-compare VERSION1 OPERATOR VERSION2
# Operators: lt, le, eq, ne, ge, gt
# Returns: 0 (true) or 1 (false)

set -e

usage() {
    echo "usage: $0 version1 operator version2"
    echo "operators: lt (less than), le (less or equal), eq (equal),"
    echo "           ne (not equal), ge (greater or equal), gt (greater than)"
    echo "   ie: $0 8.4.0 ge 8.3.0"
}

if [ $# -ne 3 ]; then
    usage >&2
    exit 1
fi

VERSION1="$1"
OPERATOR="$2"
VERSION2="$3"

# Determine order using sort -V
SORTED_FIRST=$(printf '%s\n%s\n' "$VERSION1" "$VERSION2" | sort -V | head -n1)

case "$OPERATOR" in
    lt)
        # VERSION1 < VERSION2: V1 must sort first AND not be equal
        [ "$VERSION1" != "$VERSION2" ] && [ "$SORTED_FIRST" = "$VERSION1" ] && exit 0 || exit 1
        ;;
    le)
        # VERSION1 <= VERSION2: V1 must sort first or be equal
        [ "$SORTED_FIRST" = "$VERSION1" ] && exit 0 || exit 1
        ;;
    eq)
        [ "$VERSION1" = "$VERSION2" ] && exit 0 || exit 1
        ;;
    ne)
        [ "$VERSION1" != "$VERSION2" ] && exit 0 || exit 1
        ;;
    ge)
        # VERSION1 >= VERSION2: V2 must sort first or be equal
        [ "$SORTED_FIRST" = "$VERSION2" ] && exit 0 || exit 1
        ;;
    gt)
        # VERSION1 > VERSION2: V2 must sort first AND not be equal
        [ "$VERSION1" != "$VERSION2" ] && [ "$SORTED_FIRST" = "$VERSION2" ] && exit 0 || exit 1
        ;;
    *)
        echo >&2 "error: unknown operator '$OPERATOR'"
        usage >&2
        exit 1
        ;;
esac