Merge pull request #623 from rubenvereecken/master

Added dpkg-query to linux

pages/linux/dpkg-query.md

@@ -0,0 +1,19 @@
+# dpkg-query
+
+> A tool that shows information about installed packages.
+
+- List all installed packages.
+
+`dpkg-query -l`
+
+- List installed packages matching a pattern.
+
+`dpkg-query -l '{{pattern}}'`
+
+- List all files installed by a package.
+
+`dpkg-query -L {{package_name}}`
+
+- Show information about a package.
+
+`dpkg-query -s {{package_name}}`