# ud

A clean, minimalist, robust C utility designed to automate Debian-based Linux system maintenance tasks. It manages `apt` package list updates, performs conditional upgrades, purges orphaned dependencies, clears package caches, and cleans local user thumbnail and screenshot caches.

## Features

- **Automated APT Maintenance:** Updates repository indices, checks for upgradeable packages, and runs `apt full-upgrade` only when updates exist.
- **Dependency & Cache Cleanup:** Automatically purges unused dependencies and lingering configuration files (`apt autoremove --purge`) and empties cached installer packages (`apt clean`).
- **User Cache Housekeeping:** Safely cleans desktop thumbnail caches and user screenshot directories without failing if the directories are empty.
- **Robust POSIX C Implementation:** Built using strict standard C (`-std=c11`, POSIX 2008) with explicit bounds checking on formatted buffers and POSIX exit status inspection (`WIFEXITED`, `WEXITSTATUS`).
- **Hardened & Optimized Build:** Compiled with `-O3`, `-flto`, `-march=native`, stack protection (`-fstack-protector-strong`), runtime buffer fortification (`-D_FORTIFY_SOURCE=2`), and strict warning checks (`-Wall -Wextra -Wpedantic -Werror`).
- **Clean Terminal Output:** Indents subprocess output using `sed` for a clear, readable terminal log.

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## Prerequisites & Dependencies

This utility requires a **Debian-based distribution** (Debian, Ubuntu, Linux Mint, Pop!_OS, etc.) with the following installed:

- `gcc` or `clang`
- `make`
- `apt`
- `sed`
- `sudo` privileges for package management operations

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## Repository Access & Cloning

Clone the repository directly from the cgit web frontend:

```bash
git clone [https://git.davo.co/ud.git](https://git.davo.co/ud.git)
```

---

## Build Instructions

To compile the executable using `make`:

```bash
# Build the utility with maximum optimization and hardening flags
make

# Install the binary to ~/.local/bin
make install

# Clean build artifacts
make clean

# Uninstall the binary from ~/.local/bin
make uninstall
```

---

## Execution Instructions

Run the utility directly from your terminal:

```bash
# Run directly from the source directory
./ud

# Or run from anywhere if ~/.local/bin is in your $PATH
ud
```