add datetime

Cargo.toml

@@ -11,3 +11,4 @@ license = "MIT"
 
 [dependencies]
 clap = "2.33.1"
+chrono = "0.4.13"

src/main.rs

@@ -2,28 +2,47 @@ extern crate clap;
 use clap::{App};
 use std::fs::OpenOptions;
 use std::io::Write;
+use std::env;
+use chrono::Local;
 
 fn main() -> std::io::Result<()>{
+    let memofile = match env::var("MEMO_FILE") {
+        Ok(x) => x,
+        Err(_) => "note.txt".to_string(),
+    };
+    let date_format = match env::var("MEMO_DATE_FORMAT") {
+        Ok(x) => x,
+        Err(_) => "%Y/%m/%d %H:%M:%S".to_string(),
+    };
     let matches = App::new("memo")
         .about(clap::crate_description!())
         .version(clap::crate_version!())
         .author(clap::crate_authors!())
         .args_from_usage("<sentence> 'sentence you want to note'")
         .get_matches();
-
     let sentence = match matches.value_of("sentence") {
-        Some(x) => x,
+        Some(x) => x.to_string(),
         None => {
             eprintln!("empty sentence");
             std::process::exit(1);
         },
     };
+    let datetime = Local::now().format(&date_format).to_string();
+    let sentence = join_sentence(datetime, sentence);
+    memo(memofile, sentence)?;
+    Ok(())
+}
 
+fn memo(memofile: String, sentence: String) -> std::io::Result<()> {
     let mut file = OpenOptions::new()
         .append(true)
         .create(true)
-        .open("note.txt")?;
+        .open(memofile)?;
     write!(file, "{}\n", sentence)?;
     file.flush()?;
-    Ok(())
+    return Ok(());
+}
+
+fn join_sentence(sentence1: String, sentence2: String) -> String {
+    format!("{} {}", sentence1, sentence2)
 }