Cleanup solana-genesis

src/bin/genesis.rs

@@ -6,31 +6,27 @@ extern crate solana;
 
 use atty::{is, Stream};
 use solana::mint::Mint;
-use std::io::{stdin, Read};
+use std::error;
+use std::io::{stdin, stdout, Read, Write};
 use std::process::exit;
 
-fn main() {
+fn main() -> Result<(), Box<error::Error>> {
     if is(Stream::Stdin) {
         eprintln!("nothing found on stdin, expected a json file");
         exit(1);
     }
 
     let mut buffer = String::new();
-    let num_bytes = stdin().read_to_string(&mut buffer).unwrap();
+    let num_bytes = stdin().read_to_string(&mut buffer)?;
     if num_bytes == 0 {
         eprintln!("empty file on stdin, expected a json file");
         exit(1);
     }
 
-    let mint: Mint = serde_json::from_str(&buffer).unwrap_or_else(|e| {
-        eprintln!("failed to parse json: {}", e);
-        exit(1);
-    });
+    let mint: Mint = serde_json::from_str(&buffer)?;
+    let mut writer = stdout();
     for x in mint.create_entries() {
-        let serialized = serde_json::to_string(&x).unwrap_or_else(|e| {
-            eprintln!("failed to serialize: {}", e);
-            exit(1);
-        });
-        println!("{}", serialized);
+        writeln!(writer, "{}", serde_json::to_string(&x)?)?;
     }
+    Ok(())
 }