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Menu System - Dialog Tool

The dev-setup menu uses dialog - a tool for creating text-based user interfaces (TUI) in shell scripts.

Why Dialog?​

FeatureBenefit
Terminal-basedWorks in SSH, containers, any terminal
Keyboard navigationArrow keys, Tab, Enter for navigation
No dependenciesPart of most Linux distributions
AccessibleWorks with screen readers
ScriptableCaptures user input via exit codes and stdout

Dialog Installation​

Dialog is installed in the base devcontainer image (Dockerfile.base):

RUN apt-get update && apt-get install -y dialog

Dialog Widgets​

1. Menu Widget (--menu)​

Primary navigation - single selection from a list:

choice=$(dialog --clear \
    --title "Main Menu" \
    --menu "Choose an option:" \
    20 80 12 \           # height width menu-height
    "1" "Browse & Install Tools" \
    "2" "Manage Services" \
    "3" "Setup & Configuration" \
    2>&1 >/dev/tty)

2. Menu with Item Help (--item-help)​

Adds context-sensitive help text at bottom of screen:

choice=$(dialog --clear \
    --item-help \
    --title "Select Tool" \
    --menu "Choose a tool:" \
    20 80 12 \
    "1" "Go Runtime" "Install Go development environment" \
    "2" "Python" "Install Python with pip and tools" \
    2>&1 >/dev/tty)

3. Checklist Widget (--checklist)​

Multiple selection with on/off toggles:

selected=$(dialog --clear \
    --title "Auto-Start Services" \
    --checklist "Select services to auto-start:" \
    20 80 12 \
    "1" "Nginx Proxy" "on" \
    "2" "OTEL Collector" "off" \
    2>&1 >/dev/tty)

4. Input Box (--inputbox)​

Text input for parameters:

version=$(dialog --clear \
    --title "Version" \
    --inputbox "Enter Go version:" \
    8 60 \
    2>&1 >/dev/tty)

5. Message Box (--msgbox)​

Display information or errors:

dialog --title "Success" \
    --msgbox "Installation complete!" \
    8 50

6. Yes/No Dialog (--yesno)​

Confirmation prompts:

if dialog --title "Confirm" --yesno "Proceed with installation?" 8 50; then
    # User said yes
fi

Dialog Output Handling​

Dialog writes selections to stderr (not stdout), so we redirect:

# Capture selection
choice=$(dialog ... 2>&1 >/dev/tty)

# Check exit code
if [[ $? -ne 0 ]]; then
    # User pressed ESC or Cancel
    return
fi

Dialog Dimensions​

Standard dimensions used in dev-setup.sh:

DIALOG_HEIGHT=20   # Total dialog height
DIALOG_WIDTH=80    # Total dialog width
MENU_HEIGHT=12     # Number of visible menu items

Status Icons in Menus​

The system uses Unicode/emoji for status display:

IconMeaning
✅Installed / Configured / Running
❌Not installed / Not configured / Stopped
⏸️Service stopped
[AI], [DEV]Category prefixes

References​