diff --git a/scripts/commit-msg.crs b/scripts/commit-msg.crs
index 35271df..cbf28d7 100755
--- a/scripts/commit-msg.crs
+++ b/scripts/commit-msg.crs
@@ -4,6 +4,15 @@ use std::{ env, fs, process };
 use std::path::PathBuf;
 use std::os::unix::fs::PermissionsExt;
 
+const RED: &str    = "\x1B[91m";
+const GREEN: &str  = "\x1B[92m";
+const YELLOW: &str = "\x1B[93m";
+const BOLD: &str   = "\x1B[1m";
+const UNDER: &str  = "\x1B[4m";
+const END: &str    = "\x1B[0m";
+
+const DEFAULT_COMMIT_MSG_REGEXP: &str = "^(feat|fix|docs|style|refactor|test|chore)(\\([\\w\\-_.]+\\))?:\\s*.*";
+
 /// Git commit message format check util
 ///
 /// Commit format MUST be <type>(<scope>): subject
@@ -50,18 +59,10 @@ fn main() {
     }
 }
 
-const RED: &str    = "\x1B[91m";
-const GREEN: &str  = "\x1B[92m";
-const YELLOW: &str = "\x1B[93m";
-const BOLD: &str   = "\x1B[1m";
-const UNDER: &str  = "\x1B[4m";
-const END: &str    = "\x1B[0m";
-
-const DEFAULT_COMMIT_MSG_REGEXP: &str = "^(feat|fix|docs|style|refactor|test|chore)(\\([\\w\\-_.]+\\))?:\\s*.*";
-
 fn print_usage() {
-    let usage = get_commit_msg_usage();
-    if !usage.is_empty() { print_info(&usage); return; }
+    if let Some(usage) = get_commit_msg_usage() {
+        print_info(&usage); return;
+    }
     print_info(&format!(r#"Please follow the commit spec:
 Format: {b}<type>{e}(<scope>){b}: <subject>{e}
                <scope> is optional
@@ -94,9 +95,7 @@ fn search_git_root_path() -> Option<PathBuf> {
         if p.join(".git").is_dir() {
             return Some(p);
         }
-        if !p.pop() {
-            return None;
-        }
+        if !p.pop() { return None; }
     }
 }
 
@@ -105,48 +104,48 @@ fn search_git_root_path_e() -> PathBuf {
 }
 
 fn get_home_e() -> PathBuf {
-    PathBuf::from(env::var("HOME").unwrap_or_else(|e| {
-        exit_with_error_message(&format!("Get env HOME failed: {}!", e));
-    }))
+    PathBuf::from(env::var("HOME").unwrap_or_else(|e|
+        exit_with_error_message(&format!("Get env HOME failed: {}!", e))
+    ))
 }
 
-fn get_commit_msg_file(file: &str, default_content: &str) -> String {
+fn get_commit_msg_file(file: &str) -> Option<String> {
     let settings_regexp = search_git_root_path_e().join("settings").join(file);
     if settings_regexp.exists() {
         print_info(&format!("Found file: {:?}", settings_regexp));
-        return fs::read_to_string(settings_regexp).unwrap();
+        return Some(fs::read_to_string(settings_regexp).unwrap());
     }
 
     let path_regexp = search_git_root_path_e().join(".git").join("hooks").join(file);
     if path_regexp.exists() {
         print_info(&format!("Found file: {:?}", path_regexp));
-        return fs::read_to_string(path_regexp).unwrap();
+        return Some(fs::read_to_string(path_regexp).unwrap());
     }
 
     let home_path_regexp = get_home_e().join(&(".".to_owned() + file));
     if home_path_regexp.exists() {
         print_info(&format!("Found file: {:?}", home_path_regexp));
-        return fs::read_to_string(home_path_regexp).unwrap();
+        return Some(fs::read_to_string(home_path_regexp).unwrap());
     }
 
-    default_content.to_owned()
+    None
 }
 
 fn get_commit_msg_regexp() -> String {
-    get_commit_msg_file("commit-msg-regexp", DEFAULT_COMMIT_MSG_REGEXP)
+    get_commit_msg_file("commit-msg-regexp").unwrap_or_else(|| DEFAULT_COMMIT_MSG_REGEXP.to_owned())
 }
 
-fn get_commit_msg_usage() -> String {
-    get_commit_msg_file("commit-msg-regexp-usage", "")
+fn get_commit_msg_usage() -> Option<String> {
+    get_commit_msg_file("commit-msg-regexp-usage")
 }
 
 fn install_commit_msg(force: bool) {
     let commit_msg_crs = get_home_e().join("bin").join("commit-msg.crs");
-    let commig_msg_exec_file = if !commit_msg_crs.exists() {
+    let commig_msg_exec_file = if commit_msg_crs.exists() {
+        commit_msg_crs
+    } else {
         print_warn(&format!("File {:?} NOT exists!", commit_msg_crs));
         PathBuf::from(env::args().next().unwrap())
-    } else {
-        commit_msg_crs
     };
 
     let git_hooks = search_git_root_path_e().join(".git").join("hooks");
@@ -175,7 +174,7 @@ fn install_commit_msg(force: bool) {
 fn exit_with_error() -> ! { process::exit(1) }
 fn exit_with_error_message(msg: &str) -> ! { print_error(msg); exit_with_error() }
 
-fn print_info(msg: &str)  { println!("{b}[INFO ]{e} {m}", b = BOLD, e = END, m = msg); }
-fn print_ok(msg: &str)    { println!("{g}{b}[OK   ]{e} {g}{m}{e}", g = GREEN, b = BOLD, e = END, m = msg); }
+fn print_info(msg: &str)  { println!("{b}[INFO ]{e} {m}",                      b = BOLD, e = END, m = msg); }
+fn print_ok(msg: &str)    { println!("{g}{b}[OK   ]{e} {g}{m}{e}", g = GREEN,  b = BOLD, e = END, m = msg); }
 fn print_warn(msg: &str)  { println!("{y}{b}[WARN ]{e} {y}{m}{e}", y = YELLOW, b = BOLD, e = END, m = msg); }
-fn print_error(msg: &str) { println!("{r}{b}[ERROR]{e} {r}{m}{e}", r = RED, b = BOLD, e = END, m = msg); }
+fn print_error(msg: &str) { println!("{r}{b}[ERROR]{e} {r}{m}{e}", r = RED,    b = BOLD, e = END, m = msg); }