tz_selection.sh

#!/bin/sh

###########################
#   Time Zone Selection   #
# Dependencies:           #
#  - dialog               #
# Folder Structure:       #
#  ├── TZ                 #
#  │   ├── America        #
#  │   ├── Europe         #
#  │   └── . . .          #
#  └── tz_selection.sh    #
# TZ File Example:        #
#  America:               #
#    America/Sao_Paulo    #
#    ...                  #
###########################

# Directory to timezones
TZ_DIR="TZ"

# Check the TZ directory
if [ ! -d $TZ_DIR ]; then
	echo "ERROR: TZ directory not found"
	exit 1
fi

# Check for continents list
if [ ! "$(ls -A $TZ_DIR)" ]; then
	echo "ERROR: No continents found"
	exit 1
fi

# Getting the avaliable continents
TZ_CONTINENTS=`ls $TZ_DIR`

# Prepare continent list
TZ_CONTINENTS_LIST=""
TZ_CONTINENTS_COUNT=0

while read tz; do
	TZ_CONTINENTS_LIST="$TZ_CONTINENTS_LIST $tz + off"
	let TZ_CONTINENTS_COUNT=TZ_CONTINENTS_COUNT+1
done <<EOF
`echo $TZ_CONTINENTS | sed -e 's/\s/\\n/g'`
EOF

# Show continent selection dialog
SELECTED_CONTINENT=$(dialog --stdout --backtitle "Select Time Zone" \
		 --radiolist "Continent" 0 0 $TZ_CONTINENTS_COUNT   \
        	 $TZ_CONTINENTS_LIST)


# Prepare timezones list
TZ_LIST=""
TZ_COUNT=0

while read tz; do
	TZ_LIST="$TZ_LIST $tz + off"
	let TZ_COUNT=TZ_COUNT+1
done < $TZ_DIR/$SELECTED_CONTINENT

SELECTED_TZ=$(dialog --stdout --backtitle "Select Time Zone" \
	--radiolist "Time Zone" 0 0 $TZ_COUNT 	             \
	$TZ_LIST)

dialog --backtitle "Select Time Zone" --title "Info[!]" --msgbox "\nSelected TZ: $SELECTED_TZ\n " 0 0

clear

echo "Selected TZ: $SELECTED_TZ"