Use -1 as file descriptor "not open" value instead of 0

[debian/gnuradio] / gr-howto-write-a-block / grc / howto_square2_ff.xml

<?xml version="1.0"?>
<block>
  <name>Square2</name>
  <key>howto_square2_ff</key>
  <category>HOWTO</category>
  <import>import howto</import>
  <make>howto.square2_ff()</make>

  <sink>
    <name>in</name>
    <type>float</type>
  </sink>

  <source>
    <name>out</name>
    <type>float</type>
  </source>
</block>