Start work on basic CLI features

+ Add basic logic for detecting conflicting configs, prompt to abort or
  continue
+ Create symlinks to configs
+ Basic usage is `kot path/to/dotfiles/`
+ Add `--backup-dir` option for setting directory for backing up configs
+ Default backup-dir to `backups/kapper` until finished testing
+ Add `--home-dir` option for setting location to install configs
+ Default home-dir setting to `dry-runs/kapper` until finished testing

src/kot.rs

@@ -0,0 +1,41 @@
+/*##############################################################################
+## Author: Shaun Reed                                                         ##
+## Legal: All Content (c) 2021 Shaun Reed, all rights reserved                ##
+## About: Root module for Linux configuration manager kot                     ##
+##                                                                            ##
+## Contact: shaunrd0@gmail.com  | URL: www.shaunreed.com | GitHub: shaunrd0   ##
+##############################################################################*/
+
+pub mod cli;
+pub mod fs;
+pub mod io;
+
+// =============================================================================
+// IMPLEMENTATION
+// =============================================================================
+
+// -----------------------------------------------------------------------------
+
+pub fn install_configs(args: & cli::Cli) -> std::io::Result<()> {
+    // Get the configurations and their target installation paths
+    // + Checks for conflicts and prompts user to abort or continue
+    let config_map = fs::get_target_paths(&args)?;
+
+    // At this point there are either no conflicts or the user agreed to them
+    for (config_path, target_path) in &config_map {
+        println!("Installing config: {:?}\n+ At location: {:?}\n", config_path, target_path);
+
+        match std::os::unix::fs::symlink(config_path, target_path) {
+            Ok(()) => (),
+            Err(_e) => {
+                match target_path.is_dir() {
+                    true => fs_extra::dir::remove(target_path),
+                    false => fs_extra::file::remove(target_path),
+                };
+                std::os::unix::fs::symlink(config_path, target_path)
+                    .expect(&format!("Unable to symlink config: {:?}", config_path));
+            },
+        }
+    }
+    Ok(())
+}

src/kot/cli.rs

@@ -0,0 +1,69 @@
+/*##############################################################################
+## Author: Shaun Reed                                                         ##
+## Legal: All Content (c) 2021 Shaun Reed, all rights reserved                ##
+## About: Wrapper for StructOpt crate functionality used by kot               ##
+##                                                                            ##
+## Contact: shaunrd0@gmail.com  | URL: www.shaunreed.com | GitHub: shaunrd0   ##
+##############################################################################*/
+
+use structopt::StructOpt;
+
+// =============================================================================
+// STRUCTS
+// =============================================================================
+
+// -----------------------------------------------------------------------------
+
+#[derive(Debug, StructOpt)]
+#[structopt(
+    name="kot",
+    about="CLI for managing Linux user configurations"
+)]
+pub struct Cli {
+    #[structopt(
+        help="Local or full path to user configurations to install",
+        parse(from_os_str)
+    )]
+    pub configs_dir: std::path::PathBuf,
+
+    #[structopt(
+        help="The location to attempt installation of user configurations",
+        default_value="dry-runs/kapper", // TODO: Remove temp default value after tests
+        // env = "HOME", // Default value to env variable $HOME
+        long="home-dir",
+        parse(from_os_str)
+    )]
+    pub install_dir: std::path::PathBuf,
+
+    #[structopt(
+        help="The location to store backups for this user",
+        default_value="backups/kapper",
+        long="backup-dir",
+        parse(from_os_str)
+    )]
+    pub backup_dir: std::path::PathBuf,
+}
+
+// =============================================================================
+// IMPLEMENTATION
+// =============================================================================
+
+// -----------------------------------------------------------------------------
+
+// Augment implementation of from_args to limit scope of StructOpt
+// + Also enforces use of Cli::normalize()
+// https://docs.rs/structopt/0.3.23/src/structopt/lib.rs.html#1121-1126
+pub fn from_args() -> Cli {
+    let s = Cli::from_clap(&Cli::clap().get_matches());
+    s.normalize()
+}
+
+impl Cli {
+    // Helper function to normalize arguments passed to program
+    pub fn normalize(mut self) -> Self {
+        self.configs_dir = self.configs_dir.canonicalize().unwrap();
+        self.install_dir = self.install_dir.canonicalize().unwrap();
+        self.backup_dir = self.backup_dir.canonicalize().unwrap();
+        self
+    }
+}

src/kot/fs.rs

@@ -0,0 +1,67 @@
+/*##############################################################################
+## Author: Shaun Reed                                                         ##
+## Legal: All Content (c) 2021 Shaun Reed, all rights reserved                ##
+## About: Wrapper for std::fs functionality used by kot                       ##
+##                                                                            ##
+## Contact: shaunrd0@gmail.com  | URL: www.shaunreed.com | GitHub: shaunrd0   ##
+##############################################################################*/
+
+// Allow the use of kot::fs::Path and kot::fs::PathBuf from std::path::
+pub use std::path::{Path, PathBuf};
+pub use std::collections::HashMap;
+
+use std::fs;
+use fs_extra::dir;
+
+// =============================================================================
+// IMPLEMENTATION
+// =============================================================================
+
+// -----------------------------------------------------------------------------
+
+fn backup_config(config_path: & PathBuf, backup_dir: & PathBuf) -> super::io::Result<()> {
+    let mut backup_path = backup_dir.to_owned();
+    backup_path.push(config_path.file_name().unwrap());
+    match config_path.is_dir() {
+        true => {
+            let mut options = dir::CopyOptions::new();
+            options.copy_inside = true;
+            dir::move_dir(config_path, backup_path, &options)
+        },
+        false => {
+            let options = fs_extra::file::CopyOptions::new();
+            fs_extra::file::move_file(config_path, backup_path, &options)
+        },
+    };
+    Ok(())
+}
+
+// Initialize and return a HashMap<config_dir, config_install_location>
+// Later used to check each install location for conflicts before installing
+pub fn get_target_paths(args: & super::cli::Cli) -> super::io::Result<HashMap<PathBuf, PathBuf>> {
+    let mut config_map = HashMap::new();
+
+    let mut config_target = args.install_dir.to_owned();
+    for config_entry in fs::read_dir(&args.configs_dir)? {
+        match config_entry {
+            Err(err) => return Err(err),
+            Ok(entry) => {
+                config_target.push(entry.file_name());
+
+                if config_target.exists() {
+                    match super::io::prompt(format!("Configuration already exists: {:?}\nAbort? Enter y/n or Y/N: ", config_target)) {
+                        true => return Err(std::io::Error::from(std::io::ErrorKind::AlreadyExists)),//panic!("User abort"),
+                        false => backup_config(&config_target, &args.backup_dir).ok(), // TODO: Backup colliding configs
+                    };
+                };
+
+                config_map.entry(entry.path().to_owned())
+                    .or_insert(config_target.to_owned());
+
+                config_target.pop();
+            },
+        }
+
+    }
+    Ok(config_map)
+}

src/kot/io.rs

@@ -0,0 +1,30 @@
+/*##############################################################################
+## Author: Shaun Reed                                                         ##
+## Legal: All Content (c) 2021 Shaun Reed, all rights reserved                ##
+## About: Wrapper for std::io functionality used by kot                       ##
+##                                                                            ##
+## Contact: shaunrd0@gmail.com  | URL: www.shaunreed.com | GitHub: shaunrd0   ##
+##############################################################################*/
+
+// Allow use of kot::io::Result
+pub use std::io::Result;
+
+use std::io;
+
+// =============================================================================
+// IMPLEMENTATION
+// =============================================================================
+
+// -----------------------------------------------------------------------------
+
+pub fn prompt(msg: String) -> bool {
+    println!("{}", msg);
+    let mut reply = String::new();
+    io::stdin().read_line(&mut reply)
+        .expect("Failed to read user input");
+    match reply.trim() {
+        "y" | "Y" => true,
+        "n" | "N" => false,
+        _ => prompt("Please enter y/n or Y/N\n".to_owned()),
+    }
+}

src/main.rs

@@ -1,3 +1,26 @@
+/*##############################################################################
+## Author: Shaun Reed                                                         ##
+## Legal: All Content (c) 2021 Shaun Reed, all rights reserved                ##
+## About: Main entry point for Linux configuration manager kot                ##
+##                                                                            ##
+## Contact: shaunrd0@gmail.com  | URL: www.shaunreed.com | GitHub: shaunrd0   ##
+##############################################################################*/
+
+mod kot;
+
+// =============================================================================
+// MAIN ENTRY-POINT
+// =============================================================================
+
+// -----------------------------------------------------------------------------
+
 fn main() {
-    println!("Hello, world!");
+    let args = kot::cli::from_args();
+    println!("args: {:?}\n", args);
+
+    match kot::install_configs(&args) {
+        Err(e) => println!("Error: {:?}\n+ Configs used: {:?}\n+ Install directory: {:?}\n",
+                           e.kind(), args.configs_dir, args.install_dir),
+        Ok(()) => (),
+    }
 }