Udev example to symlink UPS devices in /dev/ups

99-ups-eaton.rules

SUBSYSTEM=="usb", ATTR{idVendor}=="0463", ATTR{idProduct}=="ffff", PROGRAM="/usr/local/bin/nut-usbups-name", SYMLINK+="ups/%c"

nut-usbups-name.sh

#!/bin/sh
set -e -o errexit -o pipefail -o nounset

# udev scripts are called w/o environment; depending on the distro sed can be provided in many ways (standalone, busyboxy etc)
PATH="/usr/local/bin:/usr/bin:/bin"

if ! command -v sed 2>&1 >/dev/null; then
    echo "sed is required by $0" >&2
    exit 1
fi

# Ensure the string is safe to use in a filesystem path
# Converts any non-alphanumeric to _ w/o duplicates & trim whitespaces
sanitize() {
    echo "$1" | sed -E 's/[^a-zA-Z0-9]+/_/g; s/^_+//; s/_+$//'
}

# Prepare safe name parts, with fallback to hex IDs
vendor=$(sanitize "${ID_VENDOR:-}")
model=$(sanitize "${ID_MODEL:-}")
: ${vendor:=$(sanitize "${ID_VENDOR_ID}")}
: ${model:=$(sanitize "${ID_MODEL_ID}")}

# If tr is available, try avoiding duplicated vendor name in model
if command -v tr 2>&1 >/dev/null; then
    vendorLC=$(echo "$vendor" | tr '[:upper:]' '[:lower:]')
    modelLC=$(echo "$model" | tr '[:upper:]' '[:lower:]')

    if [ "${modelLC#"$vendorLC"}" = "$modelLC" ]; then
        model="${vendor}-${model}"
    fi
else
    model="${vendor}-${model}"
fi

# Add serial, if available, to make name unique
devName="${ID_BUS}-$model"
serial=$(sanitize "${ID_SERIAL_SHORT:-}")
if ! [ -z "$serial" ]; then
    devName="${devName}-$serial"
fi

echo $devName