Deleting files before overwriting them

CHANGELOG.md

@@ -10,6 +10,7 @@ This project follows [semantic versioning](http://semver.org).
 - [changed] Set keepalive to 120 secs when NAT is detected
 - [fixed] Added parameter keepalive to manpage
 - [fixed] Fixed problems on stats file when dropping permissions
+- [fixed] Deleting files before overwriting them
 
 ### v1.1.0 (2019-12-04)
 

src/beacon.rs

@@ -213,9 +213,13 @@ impl<TS: TimeSource> BeaconSerializer<TS> {
     pub fn write_to_file<P: AsRef<Path>>(&self, peers: &[SocketAddr], path: P) -> Result<(), io::Error> {
         let beacon = self.encode(peers);
         debug!("Beacon: {}", beacon);
-        let mut f = File::create(&path)?;
+        let path = path.as_ref();
+        if path.exists() {
+            fs::remove_file(path)?
+        }
+        let mut f = File::create(path)?;
         writeln!(&mut f, "{}", beacon)?;
-        fs::set_permissions(&path, Permissions::from_mode(0o644))?;
+        fs::set_permissions(path, Permissions::from_mode(0o444))?;
         Ok(())
     }
 

src/main.rs

@@ -103,6 +103,10 @@ struct DualLogger {
 impl DualLogger {
     pub fn new<P: AsRef<Path>>(path: Option<P>) -> Result<Self, io::Error> {
         if let Some(path) = path {
+            let path = path.as_ref();
+            if path.exists() {
+                fs::remove_file(path)?
+            }
             let file = File::create(path)?;
             Ok(DualLogger { file: Mutex::new(Some(file)) })
         } else {
@@ -269,6 +273,10 @@ fn run<P: Protocol>(config: Config) {
     let stats_file = match config.stats_file {
         None => None,
         Some(ref name) => {
+            let path = Path::new(name);
+            if path.exists() {
+                try_fail!(fs::remove_file(path), "Failed to remove file {}: {}", name);
+            }
             let file = try_fail!(File::create(name), "Failed to create stats file: {}");
             try_fail!(
                 fs::set_permissions(name, Permissions::from_mode(0o644)),