Add proper logging

Cargo.toml

@@ -12,4 +12,12 @@ license = "CECILL-B"
 include = ["src/**/*", "Cargo.toml", "Licence_*.txt"]
 
 [dependencies]
-nom = "^4.1"
+log = "0.4"
+nom = "4.1"
+
+[[example]]
+name = "dummy"
+path = "examples/dummy.rs"
+
+[dev-dependencies]
+env_logger = "0.6"

examples/dummy.rs

@@ -1,3 +1,6 @@
+use env_logger::{Builder, Env};
+
 fn main() {
+    Builder::from_env(Env::default().default_filter_or("debug")).init();
     opensmtpd::run();
 }

src/errors.rs

@@ -1,4 +1,5 @@
 use crate::entry::Entry;
+use std::fmt;
 
 pub struct Error {
     message: String,
@@ -10,9 +11,11 @@ impl Error {
             message: msg.to_string(),
         }
     }
+}
 
-    pub fn display(&self) {
-        eprintln!("Error: {}", self.message);
+impl fmt::Display for Error {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "{}", self.message)
     }
 }
 

src/lib.rs

@@ -3,6 +3,7 @@ mod errors;
 
 use crate::entry::Entry;
 use crate::errors::Error;
+use log::{debug, error, warn};
 use std::collections::HashMap;
 use std::io;
 use std::sync::mpsc;
@@ -32,13 +33,12 @@ fn dispatch(
             let (tx, rx) = mpsc::channel();
             let name = entry.session_id.to_string();
             let handle = thread::Builder::new().name(name).spawn(move || {
-                println!("New thread: {}", thread::current().name().unwrap());
+                debug!(
+                    "New thread for session {}",
+                    thread::current().name().unwrap()
+                );
                 for e in rx.iter() {
-                    println!(
-                        "Debug: thread {}: {:?}",
-                        thread::current().name().unwrap(),
-                        e
-                    );
+                    debug!("thread {}: {:?}", thread::current().name().unwrap(), e);
                 }
             })?;
             sessions.insert(entry.session_id, (tx, handle));
@@ -74,13 +74,13 @@ pub fn run() {
             Ok(l) => l,
             Err(e) => {
                 graceful_exit_children(&mut sessions);
-                e.display();
+                error!("{}", e);
                 std::process::exit(1);
             }
         };
         match dispatch(&mut sessions, &line) {
             Ok(_) => {}
-            Err(e) => e.display(),
+            Err(e) => warn!("{}", e),
         }
     }
 }