adds commands to xargs and moves to pages/common

- xargs is also native to OS X

pages/common/xargs.md

@@ -0,0 +1,19 @@
+# xargs
+
+> Execute a command with piped arguments.
+
+- Main use:
+
+`{{arguments}} | xargs {{command}}`
+
+- Handle whitespace in arguments:
+
+`{{arguments_null_terminated}} | xargs -0 {{command}}`
+
+- Example: list unneeded packages with deborphan and remove them with apt-get:
+
+`sudo deborphan | xargs sudo apt-get remove`
+
+- creating variables: copy all files that start with 'M' to the Desktop
+
+`ls M* | xargs -J % cp % ~/Desktop`