Added some flags usage & refactoring.

src/main.rs

@@ -2,7 +2,9 @@ extern crate clap;
 
 use clap::{App, Arg, crate_authors, crate_name, crate_version};
 
-use crate::shred::{Shredder, Verbosity};
+use crate::shred::{Shredder, Verbosity, ShredOptions};
+use std::process::exit;
+use std::str::FromStr;
 
 mod shred;
 
@@ -25,7 +27,14 @@ fn main() {
         .arg(Arg::with_name("i")
             .short("i")
             .long("interactive")
-            .help("Enables interactive mode")
+            .help("Enables interactive mode"))
+        .arg(Arg::with_name("k")
+            .short("k")
+            .long("keep")
+            .help("Don't delete files after shredding"))
+        .arg(Arg::with_name("n")
+            .short("n")
+            .help("How many times the file must be overridden")
         )
         .get_matches();
 
@@ -38,15 +47,41 @@ fn main() {
 
     let is_recursively = params.is_present("r");
     let is_interactive = params.is_present("i");
+    let keep_files = params.is_present("k");
+    let iterations_count = if params.is_present("n") {
+        let value_option = params.value_of("n");
+        match value_option {
+            None => {
+                println!("No argument passed to the 'n' option!");
+                exit(1);
+            }
+            Some(value) => {
+                match u8::from_str(value) {
+                    Ok(number) => {
+                        number
+                    }
+                    Err(error) => {
+                        println!("{}", error.to_string());
+                        exit(1);
+                    }
+                }
+            }
+        }
+    } else {
+        3
+    };
 
     // Calling .unwrap() is safe here because "INPUT" is required (if "INPUT" wasn't
     // required we could have used an 'if let' to conditionally get the value)
     let path = params.value_of("PATH").unwrap();
 
-    Shredder::new(
-        path.to_string(),
-        is_recursively,
-        is_interactive,
-        verbosity
+    Shredder::with_options(
+        ShredOptions::new(path.to_string())
+            .set_is_interactive(is_interactive)
+            .set_is_recursive(is_recursively)
+            .set_keep_files(keep_files)
+            .set_verbosity(verbosity)
+            .set_rewrite_iterations(iterations_count)
+            .build()
     ).run();
 }

src/shred/mod.rs

@@ -1,52 +1,48 @@
 use std::cmp::Ordering;
 use std::fs;
 use std::fs::File;
-use std::io::{BufWriter, Write};
+use std::io::{BufWriter, Write, Seek, SeekFrom};
 use std::io;
 use std::process::exit;
 
 pub struct Shredder {
-    path: String,
-    is_recursively: bool,
-    is_interactive: bool,
-    verbosity: Verbosity,
+    options: ShredOptions,
 }
 
 impl Shredder {
-    pub fn new(path: String, is_recursively: bool, is_interactive: bool, verbosity: Verbosity) -> Shredder {
+    pub fn with_options(options: ShredOptions) -> Shredder {
         Shredder {
-            path,
-            is_recursively,
-            is_interactive,
-            verbosity
+            options
         }
     }
 
     pub fn run(&self) {
-        match fs::metadata(&self.path) {
+        let verbosity = &self.options.verbosity;
+        let metadata_result = fs::metadata(&self.options.path);
+        match &metadata_result {
             Ok(metadata) => {
-                if self.verbosity >= Verbosity::Average {
+                if *verbosity >= Verbosity::Average {
                     println!("Is directory: {}", metadata.is_dir());
                     println!("Is file: {}", metadata.is_file());
-                    if self.verbosity == Verbosity::High {
-                        println!("Is recursively: {}", self.is_recursively);
-                        println!("Is interactive: {}", self.is_interactive);
-                        println!("Verbosity: {:?}", &self.verbosity);
+                    if *verbosity == Verbosity::High {
+                        println!("Is recursively: {}", self.options.is_recursive);
+                        println!("Is interactive: {}", self.options.is_interactive);
+                        println!("Verbosity: {:?}", &self.options.verbosity);
                     }
                 }
             }
             Err(_) => {
-                println!("Provided path is invalid!");
+                println!("No such file or directory.");
                 exit(1);
             }
         }
-        if self.verbosity > Verbosity::None {
-            println!("Using input file: {}", &self.path);
+        if *verbosity > Verbosity::None {
+            println!("Using input file: {}", &self.options.path);
         }
 
-        if fs::metadata(&self.path).unwrap().is_file() {
-            Shredder::shred_file(&self.path, self.is_interactive);
-        } else if self.is_recursively {
+        if metadata_result.unwrap().is_file() {
+            Shredder::shred_file(&self.options);
+        } else if self.options.is_recursive {
 
         } else {
             println!("Target is a directory!");
@@ -54,37 +50,46 @@ impl Shredder {
         }
     }
 
-    fn shred_file(path: &String, is_interactive: bool) {
-        match std::fs::canonicalize(path) {
+    fn shred_file(options: &ShredOptions) {
+        match std::fs::canonicalize(&options.path) {
             Ok(path) => {
-                if is_interactive {
-                    let file_length = path.metadata().unwrap().len();
-                    let absolute_path = path.to_str().unwrap();
-                    println!("Do you really want to shred '{}'? [Y/n]", absolute_path);
+                let file_length = path.metadata().unwrap().len();
+                let absolute_path = path.to_str().unwrap();
+                if options.is_interactive {
+                    print!("Do you really want to shred '{}'? [Y/n] ", absolute_path);
+                    io::stdout().flush().unwrap();
 
                     let mut input = String::new();
                     io::stdin().read_line(&mut input).expect("Failed to read input.");
                     let input = input.trim();
 
-                    if input.len() == 1 && input.to_lowercase().eq("y") {
-                        match File::create(absolute_path) {
-                            Ok(file) => {
-                                println!("File's size: {}", file_length);
-                                let mut buffer = BufWriter::new(&file);
+                    if input.len() != 1 || !input.to_lowercase().eq("y") {
+                        return;
+                    }
+                }
 
-                                let random_bytes: Vec<u8> = (0..file_length).map(|_| {
-                                   rand::random::<u8>()
-                                }).collect();
-                                buffer.write(&random_bytes).unwrap();
+                match File::create(absolute_path) {
+                    Ok(file) => {
+                        println!("File's size: {}", file_length);
+                        let mut buffer = BufWriter::new(&file);
 
-                                buffer.flush().unwrap();
-                                file.sync_all().unwrap();
-                            }
-                            Err(error) => {
-                                println!("{}", error);
-                            }
+                        for _ in 0..options.rewrite_iterations {
+                            let random_bytes: Vec<u8> = (0..file_length).map(|_| {
+                                rand::random::<u8>()
+                            }).collect();
+                            buffer.write(&random_bytes).unwrap();
+
+                            buffer.flush().unwrap();
+                            file.sync_all().unwrap();
+                            buffer.seek(SeekFrom::Start(0)).unwrap();
                         }
 
+                        if !options.keep_files {
+                            fs::remove_file(absolute_path).unwrap();
+                        }
+                    }
+                    Err(error) => {
+                        println!("{}", error);
                     }
                 }
             }
@@ -95,6 +100,56 @@ impl Shredder {
     }
 }
 
+pub struct ShredOptions {
+    verbosity: Verbosity,
+    is_recursive: bool,
+    is_interactive: bool,
+    rewrite_iterations: u8,
+    keep_files: bool,
+    path: String,
+}
+
+impl ShredOptions {
+    pub fn new(path: String) -> ShredOptions {
+        ShredOptions {
+            path,
+            is_interactive: true,
+            is_recursive: false,
+            rewrite_iterations: 3,
+            keep_files: false,
+            verbosity: Verbosity::None,
+        }
+    }
+
+    pub fn set_verbosity(mut self, verbosity: Verbosity) -> ShredOptions {
+        self.verbosity = verbosity;
+        self
+    }
+
+    pub fn set_is_recursive(mut self, is_recursive: bool) -> ShredOptions {
+        self.is_recursive = is_recursive;
+        self
+    }
+
+    pub fn set_is_interactive(mut self, is_interactive: bool) -> ShredOptions {
+        self.is_interactive = is_interactive;
+        self
+    }
+
+    pub fn set_keep_files(mut self, is_keep_files: bool) -> ShredOptions {
+        self.keep_files = is_keep_files;
+        self
+    }
+
+    pub fn set_rewrite_iterations(mut self, count: u8) -> ShredOptions {
+        self.rewrite_iterations = count;
+        self
+    }
+
+    pub fn build(self) -> ShredOptions {
+        self
+    }
+}
 
 #[derive(Debug, Eq)]
 pub enum Verbosity {