Append s-meter value to file with placeholders for time, lat, long.

src/main.rs

@@ -1,11 +1,12 @@
 use serialport::DataBits;
 use serialport::Parity;
 use serialport::StopBits;
+use std::fs::OpenOptions;
 use std::io::ErrorKind;
 use std::io::Write;
 use std::thread::sleep;
 use std::time::Duration;
-use core::iter::repeat;
+use std::{error::Error};
 
 fn get_smeter(comport: &str) -> String {
     let mut port = serialport::new(comport, 4800)
@@ -53,16 +54,55 @@ fn get_smeter(comport: &str) -> String {
     }
 }
 
+// Write row to a file
+fn write_row(str_arr: [String; 4], file: &str) -> Result<(), Box<dyn Error>> {
+    // From https://docs.rs/csv/latest/csv/tutorial/index.html#writing-csv
+    let file = OpenOptions::new()
+        .write(true)
+        .create(true)
+        .append(true)
+        .open(file)
+        .unwrap();
+    let mut wtr = csv::Writer::from_writer(file);
+
+    // Since we're writing records manually, we must explicitly write our
+    // header record. A header record is written the same way that other
+    // records are written.
+    // wtr.write_record(["City", "State", "Population", "Latitude", "Longitude"])?;
+    // wtr.write_record(["Davidsons Landing", "AK", "", "65.2419444", "-165.2716667"])?;
+    // wtr.write_record(["Kenai", "AK", "7610", "60.5544444", "-151.2583333"])?;
+    // wtr.write_record(["Oakman", "AL", "", "33.7133333", "-87.3886111"])?;
+    wtr.write_record(str_arr);
+
+    // A CSV writer maintains an internal buffer, so it's important
+    // to flush the buffer when you're done.
+    wtr.flush()?;
+    Ok(())
+}
+
 fn main() {
     let port: &str = "/dev/tty.usbmodem1101";
 
     // Simple test loop to make sure we are getting values each time
-    for _i in 1..101 {
-        let a = get_smeter(port);
+    for _i in 1..11 {
+        let s_val = get_smeter(port);
         //println!("{a}");
-        match a.parse::<i32>() {
-            Ok(n) => println!("{} {}", a, "#".repeat(n.try_into().unwrap())),
-            Err(e) => todo!(),
-            }
+        match s_val.parse::<i32>() {
+            Ok(n) => println!("{} {}", s_val, "#".repeat(n.try_into().unwrap())),
+            Err(_e) => todo!(),
+        }
+
+        if let Err(err) = write_row(
+            [
+                "time".to_string(),
+                "lat".to_string(),
+                "lon".to_string(),
+                s_val.to_string(),
+            ],
+            "out/test.csv",
+        ) {
+            println!("{}", err);
+            // process::exit(1);
+        }
     }
 }