source: scripts/usr/local/lib/7dtd/serverconfig.sh

#!/bin/bash

#   Copyright 2016 Christian 'Alloc' Illy
#
#   Licensed under the Apache License, Version 2.0 (the "License");
#   you may not use this file except in compliance with the License.
#   You may obtain a copy of the License at
#
#       http://www.apache.org/licenses/LICENSE-2.0
#
#   Unless required by applicable law or agreed to in writing, software
#   distributed under the License is distributed on an "AS IS" BASIS,
#   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
#   See the License for the specific language governing permissions and
#   limitations under the License.



#################################
## Generic worker functions


# Query for an instance name (will be saved in $INSTANCE)
readInstanceName() {
        until [ $(isValidInstanceName "$INSTANCE") -eq 1 ]; do
                read -p "Instance name: " INSTANCE
                if [ $(isValidInstanceName "$INSTANCE") -eq 0 ]; then
                        echo "Invalid instance name, may only contain:"
                        echo " - letters (A-Z / a-z)"
                        echo " - digits (0-9)"
                        echo " - underscores (_)"
                        echo " - hyphens (-)"
                fi
        done
}


# Check if the config template exists
# Returns:
#   0/1: no/yes
configTemplateExists() {
        if [ -f $SDTD_BASE/templates/config.xml ]; then
                echo 1
        else
                echo 0
        fi
}

# Get a single value from a serverconfig
# Params:
#   1: Instance name
#   2: Property name
# Returns:
#   Property value
getConfigValue() {
        local CONF=$(getInstancePath $1)/config.xml
        $XMLSTARLET sel -t -v "/ServerSettings/property[@name='$2']/@value" $CONF
}

# Update a single value in a serverconfig
# Params:
#   1: Instance name
#   2: Property name
#   3: New value
setConfigValue() {
        local XMLSTARLET_OPTS="-L -P"
        local CONF=$(getInstancePath $1)/config.xml
        local XPATHBASE="//property[@name='$2']"
        
        if [ -z $($XMLSTARLET sel -t -v "$XPATHBASE/@name" $CONF) ]; then
                $XMLSTARLET ed $XMLSTARLET_OPTS \
                        -s "/*[1]" -t elem -n "property" \
                        -i "//property[not(@name)]" -t attr -n "name" -v "$2" \
                        -i "$XPATHBASE" -t attr -n "value" -v "$3" \
                        $CONF
        else
                $XMLSTARLET ed $XMLSTARLET_OPTS -u "$XPATHBASE/@value" -v "$3" $CONF
        fi
}