# HG changeset patch
# User Laurens Holst <laurens@grauw.nl>
# Date 1644719622 -3600
#      Sun Feb 13 03:33:42 2022 +0100
# Node ID 9365e9ac1134ab6969526901ad87f61fb2af6dd2
# Parent  1dcce6cbc0c695cf8160166e48c446931abeac6e
Assembler: Show version information when run without arguments.

diff --git a/CHANGES.md b/CHANGES.md
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -11,6 +11,7 @@
   * The `"` character can now be written as `""` in string literals.
   * Documented the `end` directive, supported since the initial release.
   * The source file encoding is changed from ISO-8859-1 to UTF-8.
+  * Glass now shows version information when run without arguments.
 
 Glass 0.5 — 2017-01-18
 ----------------------
diff --git a/pom.xml b/pom.xml
--- a/pom.xml
+++ b/pom.xml
@@ -60,6 +60,22 @@
 				</configuration>
 			</plugin>
 			<plugin>
+				<groupId>org.codehaus.mojo</groupId>
+				<artifactId>buildnumber-maven-plugin</artifactId>
+				<version>3.0.0</version>
+				<executions>
+					<execution>
+					<phase>validate</phase>
+					<goals>
+						<goal>create</goal>
+					</goals>
+					</execution>
+				</executions>
+				<configuration>
+					<revisionOnScmFailure>${maven.build.timestamp}</revisionOnScmFailure>
+				</configuration>
+			</plugin>
+			<plugin>
 				<groupId>org.apache.maven.plugins</groupId>
 				<artifactId>maven-jar-plugin</artifactId>
 				<version>3.2.2</version>
@@ -67,7 +83,11 @@
 					<archive>
 						<manifest>
 							<mainClass>${mainClass}</mainClass>
+							<addDefaultImplementationEntries>true</addDefaultImplementationEntries>
 						</manifest>
+						<manifestEntries>
+							<Implementation-Version>${project.version} (${buildNumber})</Implementation-Version>
+						</manifestEntries>
 					</archive>
 				</configuration>
 			</plugin>
diff --git a/src/main/java/nl/grauw/glass/Assembler.java b/src/main/java/nl/grauw/glass/Assembler.java
--- a/src/main/java/nl/grauw/glass/Assembler.java
+++ b/src/main/java/nl/grauw/glass/Assembler.java
@@ -20,6 +20,12 @@
 	 */
 	public static void main(String[] args) {
 		if (args.length == 0) {
+			System.out.println(String.format("%s %s by %s",
+				Assembler.class.getPackage().getImplementationTitle(),
+				Assembler.class.getPackage().getImplementationVersion(),
+				Assembler.class.getPackage().getImplementationVendor()
+			));
+			System.out.println();
 			System.out.println("Usage: java -jar glass.jar [OPTION] SOURCE [OBJECT] [SYMBOL]");
 			System.exit(1);
 		}