start work on byte matching

src/main.rs

@@ -19,7 +19,7 @@ pub fn main() -> Result<(), Error> {
         .version(env!("CARGO_PKG_VERSION"))
         .author(env!("CARGO_PKG_AUTHORS"))
         .about(env!("CARGO_PKG_DESCRIPTION"))
-        .arg(arg!(--i <VALUE>).required(true))
+        .arg(arg!(--i <SBFfile>).required(true))
         .get_matches();
     let filepath: String = matches.get_one::<String>("i").unwrap().to_string();
     let rinexrec = sbf2rnxrec(filepath);
@@ -33,11 +33,7 @@ fn sbf2rnxrec(filepath: String) -> Rinex {
 
     let rrecord: Rinex = Rinex::default();
     match std::fs::read(Path::new(&filepath).as_os_str()) {
-        Ok(bytes) => {
-            for byte in bytes {
-                eprintln!("Read byte {}", byte);
-            }
-        }
+        Ok(bytes) => { process_sbfdata(bytes) }
         Err(e) => {
             if e.kind() == std::io::ErrorKind::NotFound {
                 eprintln!("Please check path {}", &filepath);
@@ -54,6 +50,15 @@ fn sbf2rnxrec(filepath: String) -> Rinex {
     rrecord
 }
 
+fn process_sbfdata(bytes: Vec<u8>) {
+    const SBF_SYNC1: u8 = 0x24;        /* SBF message header sync field 1 (correspond to $) */
+    const SBF_SYNC2: u8 = 0x40;        /* SBF message header sync field 2 (correspond to @)*/
+    // let's find SBF blocks by their sync bytes
+    for byte in bytes {
+        eprintln!("Read byte {}", byte);
+    }
+}
+
 fn write_rnx_file(rinexrec: Rinex) {
     rinexrec.to_file("test.rnx").expect("Error: RINEX writeout failed.");
 }