update-alternatives: add page (#1544)

pages/linux/update-alternatives.md

@@ -0,0 +1,19 @@
+# update-alternatives
+
+> A convenient tool for maintaining symbolic links to determine default commands.
+
+- Add a symbolic link:
+
+`sudo update-alternatives --install {{path/to/symlink}} {{command_name}} {{path/to/command_binary}} {{priority}}`
+
+- Configure a symbolic link for "java":
+
+`sudo update-alternatives --config {{java}}`
+
+- Remove a symbolic link:
+
+`sudo update-alternatives --remove {{java}} {{/opt/java/jdk1.8.0_102/bin/java}}`
+
+- Display information about a specified command:
+
+`update-alternatives --display {{java}}`