server: Only write CSV headers when initially creating the log file

diff --git a/server/src/main.rs b/server/src/main.rs
index 62ef41ef40a71d5fd436739ef2e15f1b83c2dd01..573edc580a8a99fc1671e37cb9cb90f6df108c88 100644 (file)
--- a/server/src/main.rs
+++ b/server/src/main.rs
@@ -81,12 +81,15 @@ impl Range {
 }
 
 fn main() {
+    let log_file_exists = std::path::Path::new(LOGFILENAME).exists();
     let logfile = std::fs::OpenOptions::new()
-        .create(true)
+        .create_new(!log_file_exists)
         .append(true)
         .open(LOGFILENAME)
         .expect("Coudln't open log file");
-    let mut log = csv::Writer::from_writer(logfile);
+    let mut log = csv::WriterBuilder::new()
+        .has_headers(!log_file_exists)
+        .from_writer(logfile);
     let mut presses = HashMap::<MessageKey, Range>::new();
     let socket = UdpSocket::bind("0.0.0.0:29803").expect("couldn't bind to address");
     loop {