navcat

A terminal UI for inspecting Android logcat output from TomTom navigation SDK. Filters by navigation category, highlights by tag type, and lets you toggle filters at runtime without restarting.

Installation

cargo install --path .

Usage

# Live mode — streams from a connected device via adb
navcat

# File mode — loads a saved logcat file into the TUI
navcat -f logcat.txt

TUI Key Bindings

Key	Action
n	Toggle navigation logs (progress, tracking, waypoints)
g	Toggle guidance logs
r	Toggle routing logs
m	Toggle map-matching logs
/	Open search bar — filters visible lines as you type
Enter	Lock search query and close bar
Esc	Clear search query
↑ / k	Scroll up one line
↓ / j	Scroll down one line
PgUp / Ctrl+U	Scroll up half a page
PgDn / Ctrl+D	Scroll down half a page
f / End	Resume follow mode (tail)
?	Toggle key binding hint in status bar
q q	Quit (double-press)

Filter Categories

The four toggles are independent — only categories that are on contribute logs to the visible set. All four off means nothing is shown.

Toggle	Matches tags containing
n navigation	everything not in the other three categories
g guidance	Guidance, Warning
r routing	Planner, Replan
m map-matching	Match, Project

Search (/) stacks on top of the category filters — e.g. routing-only logs narrowed to lines containing "timeout".

Tag Colors

Color	Category
Blue	Navigation (default)
Magenta	Guidance
Bold red	Routing
Yellow	Map-matching

CLI Options

-f, --file <FILE>              Load a logcat file instead of live mode
-    --serial <SERIAL>         Target adb device serial for live mode
-l, --logcat-levels <LEVELS>   Log levels to show, comma-separated [default: I,D,E,W]
-t, --tags <TAGS>              Override the default tag filter list
-a, --add-tag <TAG>            Add tags on top of the default list
-n, --no-tag-filter            Show all tags (disable tag filtering)
-i, --highlighted-items <...>  Terms to highlight in yellow background
-s, --show-items <...>         Only show lines containing these terms
    --debug-level <LEVEL>       Internal logging: none/error/info/debug [default: none]

Shell Completion

mkdir -p ~/.zfunc
navcat --completions zsh > ~/.zfunc/_navcat

# Add to ~/.zshrc if not already there:
# fpath=(~/.zfunc $fpath)
# autoload -Uz compinit && compinit

After reloading your shell, navcat -f <tab> completes to .txt files only.

Alternatives

Android Studio logcat — good for correlating logs with stack traces and crash reports in one window. navcat adds runtime category toggles, stacked search, and a persistent buffer that survives device disconnects. If you're already in AS debugging a crash, stay there. If you're live on a device hunting a replan or map-matching event, navcat is faster.

Chipmunk — a full-featured desktop log analysis tool with DLT/SomeIP support, graphing, reusable filter sets, and no file size limits. Use Chipmunk for deep post-mortem analysis of large traces or when working with automotive formats. Use navcat for live adb sessions and quick TomTom nav SDK inspection without setup.

Requirements

• Rust 1.70+
• adb on PATH (live mode only)
• Android device or emulator in device state (live mode only)

License

MIT