#1788: Created a commandlet to simulate the behaviour of ln -s

.editorconfig

@@ -18,7 +18,7 @@ ij_wrap_on_typing = false
 
 [*.properties]
 ij_properties_align_group_field_declarations = false
-ij_properties_keep_blank_lines = true
+ij_properties_keep_blank_lines = false
 ij_properties_key_value_delimiter = equals
 ij_properties_spaces_around_key_value_delimiter = false
 
@@ -354,4 +354,4 @@ ij_yaml_keep_line_breaks = true
 ij_yaml_sequence_on_new_line = false
 ij_yaml_space_before_colon = false
 ij_yaml_spaces_within_braces = true
-ij_yaml_spaces_within_brackets = true
+ij_yaml_spaces_within_brackets = true

CHANGELOG.adoc

@@ -13,6 +13,8 @@ Release with new features and bugfixes:
 * https://github.com/devonfw/IDEasy/issues/1174[#1174]: Add UrlUpdater for Java Azul edition
 * https://github.com/devonfw/IDEasy/issues/451[#451]: Automatically remove macOS quarantine attribute after tool extraction
 * https://github.com/devonfw/IDEasy/issues/1823[#1823]: Fix IDEasy creates duplicate entries in .gitconfig
+* https://github.com/devonfw/IDEasy/issues/1788[#1788]: Add Commandlet to create links
+
 
 The full list of changes for this release can be found in https://github.com/devonfw/IDEasy/milestone/44?closed=1[milestone 2026.05.001].
 

cli/src/main/java/com/devonfw/tools/ide/commandlet/CommandletManagerImpl.java

@@ -103,6 +103,7 @@ public CommandletManagerImpl(IdeContext context) {
     add(new StatusCommandlet(context));
     add(new RepositoryCommandlet(context));
     add(new UninstallCommandlet(context));
+    add(new LnCommandlet(context));
     add(new UpdateCommandlet(context));
     add(new UpgradeSettingsCommandlet(context));
     add(new CreateCommandlet(context));

cli/src/main/java/com/devonfw/tools/ide/commandlet/LnCommandlet.java

@@ -0,0 +1,186 @@
+package com.devonfw.tools.ide.commandlet;
+
+import java.nio.file.AccessDeniedException;
+import java.nio.file.FileStore;
+import java.nio.file.FileSystemException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.devonfw.tools.ide.cli.CliException;
+import com.devonfw.tools.ide.context.IdeContext;
+import com.devonfw.tools.ide.property.KeywordProperty;
+import com.devonfw.tools.ide.property.StringProperty;
+
+/**
+ * // * Link creation {@link Commandlet} similar to {@code ln -s}.
+ * <p>
+ * It tries to create a true symbolic link first. On Windows, symlink creation may be restricted due to missing privileges. In that case, IDEasy will create a
+ * hard link as an alternative (file-only, same volume) to avoid the Git-Bash behavior of silently copying files.
+ */
+public final class LnCommandlet extends Commandlet {
+
+  private static final Logger LOG = LoggerFactory.getLogger(LnCommandlet.class);
+
+  /** Grammar token {@code -s} (required). */
+  public final KeywordProperty symbolic;
+
+  /** The source path to link to. */
+  public final StringProperty source;
+
+  /** The target path (the created link). */
+  public final StringProperty target;
+
+  /**
+   * The constructor.
+   *
+   * @param context the {@link IdeContext}.
+   */
+  public LnCommandlet(IdeContext context) {
+
+    super(context);
+    addKeyword(getName());
+
+    // Treat -s as grammar token
+    this.symbolic = add(new KeywordProperty("-s", true, null));
+
+    this.source = add(new StringProperty("", true, "source"));
+    this.target = add(new StringProperty("", true, "target"));
+  }
+
+  @Override
+  public String getName() {
+
+    return "ln";
+  }
+
+  @Override
+  public boolean isIdeRootRequired() {
+
+    return false;
+  }
+
+  @Override
+  public boolean isIdeHomeRequired() {
+
+    return false;
+  }
+
+  @Override
+  public boolean isWriteLogFile() {
+
+    return false;
+  }
+
+  @Override
+  protected void doRun() {
+
+    Path cwd = this.context.getCwd();
+    if (cwd == null) {
+      throw new CliException("Missing current working directory!");
+    }
+
+    Path sourcePath = cwd.resolve(this.source.getValue()).normalize().toAbsolutePath();
+    Path targetPath = cwd.resolve(this.target.getValue()).normalize().toAbsolutePath();
+
+    if (!Files.exists(sourcePath)) {
+      throw new CliException("Source does not exist: " + sourcePath);
+    }
+    if (Files.exists(targetPath)) {
+      throw new CliException("Target already exists: " + targetPath);
+    }
+
+    // 1) Try true symlink first (desired behavior).
+    try {
+      Files.createSymbolicLink(targetPath, sourcePath);
+      LOG.info("Created symbolic link {} -> {}", targetPath, sourcePath);
+    } catch (Exception symlinkError) {
+
+      // 2) If Windows blocks symlink creation due to missing privileges:
+      //    create hard link as an alternative (never copy).
+      if (this.context.getSystemInfo().isWindows() && isWindowsSymlinkPrivilegeProblem(symlinkError)) {
+        createHardLink(sourcePath, targetPath, symlinkError);
+        return;
+      }
+
+      // Otherwise: real failure
+      throw new CliException("Failed to create symbolic link " + targetPath + " -> " + sourcePath, symlinkError);
+    }
+  }
+
+  /**
+   * Detects common Windows privilege failures for symlink creation.
+   */
+  private boolean isWindowsSymlinkPrivilegeProblem(Exception e) {
+
+    if (e instanceof AccessDeniedException) {
+      return true;
+    }
+    if (e instanceof FileSystemException fse) {
+      String msg = fse.getMessage();
+      if (msg != null) {
+        String m = msg.toLowerCase();
+        return m.contains("required privilege")
+            || m.contains("privilege is not held")
+            || m.contains("access is denied");
+      }
+    }
+    Throwable c = e.getCause();
+    while (c != null) {
+      if (c instanceof AccessDeniedException) {
+        return true;
+      }
+      c = c.getCause();
+    }
+    return false;
+  }
+
+  /**
+   * Creates a hard link as an alternative when symbolic link creation is blocked on Windows.
+   * <p>
+   * Hard links work only for files and only within the same volume.
+   */
+  private void createHardLink(Path sourcePath, Path targetPath, Exception originalSymlinkError) {
+
+    if (Files.isDirectory(sourcePath)) {
+      throw new CliException(
+          "Windows blocked symbolic link creation (missing privileges).\n"
+              + "Hard link alternative is not possible because the source is a directory.",
+          originalSymlinkError);
+    }
+
+    ensureSameVolume(sourcePath, targetPath);
+
+    try {
+      Files.createLink(targetPath, sourcePath);
+      LOG.info("Created hard link {} => {}", targetPath, sourcePath);
+      LOG.warn("NOTE: Created hard link as an alternative because Windows blocked symbolic link creation.");
+    } catch (Exception e) {
+      throw new CliException(
+          "Hard link creation failed. Source and target must be on the same volume and filesystem must support hard links.\n"
+              + "Source: " + sourcePath + "\nTarget: " + targetPath,
+          e);
+    }
+  }
+
+  private void ensureSameVolume(Path sourcePath, Path targetPath) {
+
+    try {
+      FileStore src = Files.getFileStore(sourcePath);
+      Path parent = (targetPath.getParent() != null) ? targetPath.getParent() : targetPath;
+      FileStore tgt = Files.getFileStore(parent);
+      if (!src.equals(tgt)) {
+        throw new CliException(
+            "Hard link alternative not possible: source and target are on different volumes.\n"
+                + "Source: " + sourcePath + "\nTarget: " + targetPath);
+      }
+    } catch (CliException e) {
+      throw e;
+    } catch (Exception e) {
+      throw new CliException("Failed to check volume for hard link alternative.", e);
+    }
+  }
+
+}

cli/src/main/resources/nls/Help.properties

@@ -75,6 +75,8 @@ cmd.list-editions=List the available editions of the selected tool.
 cmd.list-editions.detail=To list all available editions of e.g. 'intellij' simply type: 'ide list-editions intellij'.
 cmd.list-versions=List the available versions of the selected tool.
 cmd.list-versions.detail=To list all available versions of e.g. 'intellij' simply type: 'ide list-versions intellij'.
+cmd.ln=Create a link (ln -s).
+cmd.ln.detail=Creates a link similar to "ln -s". If symbolic links are restricted on Windows, IDEasy creates a hard link as an alternative (file-only, same volume). No copying is performed.
 cmd.mvn=Tool commandlet for Maven (Build-Tool).
 cmd.mvn.detail=Apache Maven is a build automation and dependency management tool for Java projects. Detailed documentation can be found at https://maven.apache.org/guides/index.html
 cmd.ng=Tool commandlet for Angular CLI.
@@ -169,6 +171,8 @@ val.commandlet=The selected commandlet (use 'ide help' to list all commandlets).
 val.edition=The tool edition.
 val.plugin=The plugin to select
 val.settingsRepository=The settings git repository with the IDEasy configuration for the project.
+val.source=Source
+val.target=Target
 val.tool=The tool commandlet to select.
 val.version=The tool version.
 values=Values:

cli/src/main/resources/nls/Help_de.properties

@@ -75,6 +75,8 @@ cmd.list-editions=Listet die verfügbaren Editionen des selektierten Werkzeugs a
 cmd.list-editions.detail=Um alle verfügbaren Editionen von z.B. 'intellij' aufzulisten, geben Sie einfach 'ide list-editions intellij' in die Konsole ein.
 cmd.list-versions=Listet die verfügbaren Versionen des selektierten Werkzeugs auf.
 cmd.list-versions.detail=Um alle verfügbaren Versionen von z.B. 'intellij' aufzulisten, geben Sie einfach 'ide list-versions intellij' in die Konsole ein.
+cmd.ln=Link erstellen (wie ln -s).
+cmd.ln.detail=Erstellt einen Link wie "ln -s". Wenn symbolische Links unter Windows eingeschraenkt sind, erstellt IDEasy alternativ einen Hardlink (nur Dateien, gleiches Laufwerk). Es wird nichts kopiert.
 cmd.mvn=Werkzeug Kommando für Maven (Build-Werkzeug).
 cmd.mvn.detail=Apache Maven ist ein Build-Automatisierungs- und Abhängigkeitsverwaltungstool für Java-Projekte. Detaillierte Dokumentation ist zu finden unter https://maven.apache.org/guides/index.html
 cmd.ng=Werkzeug Kommando für Angular CLI.
@@ -169,6 +171,8 @@ val.commandlet=Das ausgewählte Commandlet ("ide help" verwenden, um alle Comman
 val.edition=Die Werkzeug Edition.
 val.plugin=Die zu selektierende Erweiterung.
 val.settingsRepository=Das settings git Repository mit den IDEasy Einstellungen für das Projekt.
+val.source=Quelle
+val.target=Ziel
 val.tool=Das zu selektierende Werkzeug Kommando.
 val.version=Die Werkzeug Version.
 values=Werte:

cli/src/test/java/com/devonfw/tools/ide/commandlet/LnCommandletTest.java

@@ -0,0 +1,76 @@
+package com.devonfw.tools.ide.commandlet;
+
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.condition.EnabledOnOs;
+import org.junit.jupiter.api.condition.OS;
+
+import com.devonfw.tools.ide.context.AbstractIdeContextTest;
+import com.devonfw.tools.ide.context.IdeTestContext;
+
+/**
+ * Test of {@link LnCommandlet}.
+ */
+class LnCommandletTest extends AbstractIdeContextTest {
+
+  /**
+   * Tests a link creation on Windows.
+   */
+  @Test
+  @EnabledOnOs(OS.WINDOWS)
+  void testLnCreatesRealLinkAndReflectsChanges_Windows() throws Exception {
+    IdeTestContext context = newContext(PROJECT_BASIC);
+
+    Path testDir = context.getWorkspacePath().resolve("ln-test");
+    context.getFileAccess().mkdirs(testDir);
+    context.setCwd(testDir, context.getWorkspaceName(), context.getIdeHome());
+
+    Path source = testDir.resolve("source.txt");
+    Path link = testDir.resolve("link.txt");
+    Files.writeString(source, "A", StandardCharsets.UTF_8);
+
+    LnCommandlet cmd = new LnCommandlet(context);
+    cmd.symbolic.setValueAsString("-s", context);
+    cmd.source.setValueAsString("source.txt", context);
+    cmd.target.setValueAsString("link.txt", context);
+
+    cmd.run();
+
+    assertThat(link).exists();
+
+    Files.writeString(source, "B", StandardCharsets.UTF_8);
+    assertThat(Files.readString(link, StandardCharsets.UTF_8)).isEqualTo("B");
+  }
+
+  /**
+   * Tests a link creation on Unix.
+   */
+  @Test
+  @EnabledOnOs({ OS.LINUX, OS.MAC })
+  void testLnCreatesRealLinkAndReflectsChanges_Unix() throws Exception {
+    IdeTestContext context = newContext(PROJECT_BASIC);
+
+    Path testDir = context.getWorkspacePath().resolve("ln-test");
+    context.getFileAccess().mkdirs(testDir);
+    context.setCwd(testDir, context.getWorkspaceName(), context.getIdeHome());
+
+    Path source = testDir.resolve("source.txt");
+    Path link = testDir.resolve("link.txt");
+    Files.writeString(source, "A", StandardCharsets.UTF_8);
+
+    LnCommandlet cmd = new LnCommandlet(context);
+    cmd.symbolic.setValueAsString("-s", context);
+    cmd.source.setValueAsString("source.txt", context);
+    cmd.target.setValueAsString("link.txt", context);
+
+    cmd.run();
+
+    assertThat(link).exists();
+
+    Files.writeString(source, "B", StandardCharsets.UTF_8);
+    assertThat(Files.readString(link, StandardCharsets.UTF_8)).isEqualTo("B");
+  }
+}