add print_version

src/main.rs

@@ -124,6 +124,8 @@ fn do_with_buildin_args(args: &Vec<String>) {
      let first_arg = args.get(1).unwrap();
     if first_arg == ":::" || first_arg == ":::help" {
         print_usage();
+    } else if first_arg == ":::version" {
+        print_version();
     } else if first_arg == ":::create" {
         create_build_json(&args);
     } else if first_arg.starts_with(":::java") {

src/misc.rs

@@ -9,6 +9,7 @@ pub fn print_usage() {
     print!(r#"
 buildj :::                                           - print this message
 buildj :::help                                       - print this message
+buildj :::version                                    - print version
 buildj :::create --java<version> --maven<version>    - create java + maven project
   e.g. buildj :::create --java1.8 --maven3.5.2
 buildj :::create --java<version> --gradle<version>   - create java + gradle project
@@ -23,6 +24,15 @@ buildj                                               - run build, run assigned v
 "#);
 }
 
+pub fn print_version() {
+  print!(r#"buildj {} - {}
+Copyright (C) 2019 Hatter Jiang.
+License MIT <https://opensource.org/licenses/MIT>
+
+Written by Hatter Jiang
+"#, super::BUDERJ_VER, &super::GIT_HASH[0..7]);
+}
+
 pub fn is_verbose() -> bool {
     match env::var("BUILDJ_VERBOSE") {
         Err(_) => false,