add modules & file writing

src/args.rs

@@ -0,0 +1,11 @@
+use clap::Parser;
+
+#[derive(Parser, Debug)]
+pub struct Args {
+    #[arg(short)]
+    pub(crate) length: usize,
+    #[arg(short)]
+    pub write_to_file: bool,
+    #[arg(short, default_value_t = String::from("generated_pwd.txt"))]
+    pub file: String,
+}

src/main.rs

@@ -1,30 +1,27 @@
+use args::Args;
 use clap::Parser;
-use rand::{distributions::Alphanumeric, Rng};
+use core::panic;
+use randomstring::RandomString;
+use std::fs::File;
+use std::io::{Error, Write};
 
-#[derive(Parser, Debug)]
+mod args;
-struct Args {
+mod randomstring;
-    #[arg(short)]
-    length: usize,
-}
 
-#[derive(Debug)]
+fn main() -> Result<(), Error> {
-struct RandomString;
+    let args = Args::parse();
-
-impl RandomString {
-    fn generate_string(&self) -> String {
-        let args = Args::parse();
-        let s: String = rand::thread_rng()
-            .sample_iter(&Alphanumeric)
-            .take(args.length)
-            .map(char::from)
-            .collect();
-        s
-    }
-}
-
-fn main() {
     let random_string = RandomString;
     let string_output = random_string.generate_string();
 
-    println!("{}", string_output);
+    if args.write_to_file {
+        let f = &mut File::create(args.file);
+        let file = match f {
+            Ok(file) => file.write_all(string_output.as_bytes()),
+            Err(e) => panic!("cannot create file: {:?}", e),
+        };
+    } else {
+        println!("{}", string_output);
+    };
+
+    Ok(())
 }

src/randomstring.rs

@@ -0,0 +1,19 @@
+use clap::Parser;
+use rand::{distributions::Alphanumeric, Rng};
+
+use crate::Args;
+
+#[derive(Debug)]
+pub struct RandomString;
+
+impl RandomString {
+    pub fn generate_string(&self) -> String {
+        let args = Args::parse();
+        let s: String = rand::thread_rng()
+            .sample_iter(&Alphanumeric)
+            .take(args.length)
+            .map(char::from)
+            .collect();
+        s
+    }
+}