====== SED - File Spacing - Double space a file which already has blank lines in it ======

Output file should contain no more than one blank line between lines of text.

<code bash>
sed '/^$/d;G' filename
</code>

----

===== Example =====

Running that command again this file:

<file bash testfile>
aaa

bbb
ccc
</file>

returns:

<file bash testfile>
aaa

bbb

ccc

</file>