Mini Shell

#!/bin/sh
#
# Format:
#       bridge=<bridgename>:<bridgeslaves>
#
#       <bridgeslaves> is a comma-separated list of physical (ethernet) interfaces
#       bridge without parameters assumes bridge=br0:eth0
#

parsebridge() {
    local v=${1}:
    set --
    while [ -n "$v" ]; do
        set -- "$@" "${v%%:*}"
        v=${v#*:}
    done
    case $# in
        0)  bridgename=br0; bridgeslaves=$iface ;;
        1)  die "bridge= requires two parameters" ;;
        2)  bridgename=$1; bridgeslaves=$(str_replace "$2" "," " ") ;;
        *)  die "bridge= requires two parameters" ;;
    esac
}

# Parse bridge for bridgename and bridgeslaves
for bridge in $(getargs bridge=); do
    unset bridgename
    unset bridgeslaves
    iface=eth0
    # Read bridge= parameters if they exist
    if [ "$bridge" != "bridge" ]; then
        parsebridge $bridge
    fi
    # Simple default bridge
    if [ -z "$bridgename" ]; then
        bridgename=br0
        bridgeslaves=$iface
    fi
    echo "bridgename=$bridgename" > /tmp/bridge.${bridgename}.info
    echo "bridgeslaves=\"$bridgeslaves\"" >> /tmp/bridge.${bridgename}.info
done