use stderr when error

src/file.rs

@@ -21,7 +21,7 @@ pub fn write_readme(r: &mut Vec<Resp>) {
 
     match std::fs::write("README.md", s) {
         Ok(_) => (),
-        Err(e) => println!("写入 README.md 失败，err{}", e.to_string())
+        Err(e) => eprintln!("写入 README.md 失败，err{}", e.to_string())
     }
 }
 
@@ -41,7 +41,7 @@ pub fn get_all_bin_file() -> Vec<String> {
 pub fn write_question(resp: Resp) {
     let file = format!("src/bin/{}.rs", resp.data.question.title_slug);
     if std::path::Path::new(file.as_str()).exists() {
-        println!("{} exists", file);
+        eprintln!("{} exists", file);
         return;
     }
 

src/lib.rs

@@ -7,6 +7,8 @@ mod all;
 
 use clap::{App, Arg};
 
+use std::process;
+
 pub fn run() {
     let matches = App::new("leetcode")
         .version("0.0.1")
@@ -24,7 +26,10 @@ pub fn run() {
     if let Some(matches) = matches.subcommand_matches("new") {
         match matches.value_of_t::<String>("question_name") {
             Ok(x) => new::new(x),
-            Err(_) => println!("please input the name of question")
+            Err(_) => {
+                eprintln!("please input the name of question");
+                process::exit(1);
+            }
         }
     } else if matches.subcommand_matches("all").is_some() {
         all::all();

src/main.rs

@@ -1,3 +1,3 @@
 fn main() {
-    leetcode::run()
+    leetcode::run();
 }