title: xmlstarlet failed to load external entity
body: <p>My script is a simple one-liner that uses curl to get a URL with xml output. I'm trying to output only the text in the following tag: </p>
  
  <pre><code>&lt;TEXT&gt;No Hosts Queued for Purging&lt;/TEXT&gt;
  </code></pre>
  
  <p>My script:</p>
  
  <pre><code>curl -u username:password -H 'X-Requested-With:QualysApiExplorer' 'https://qualysapi.qualys.com:443/api/2.0/fo/asset/host/' -d "action=purge&amp;ips=$1&amp;" | xmlstarlet sel -t -m '/BATCH_RETURN/RESPONSE/BATCH_LIST/BATCH/TEXT' -v "."
  </code></pre>
  
  <p>The curl output looks like this when not using xmlstarlet:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="UTF-8" ?&gt;
  &lt;!DOCTYPE BATCH_RETURN SYSTEM "https://qualysapi.qualys.com/api/2.0/batch_return.dtd"&gt;
  &lt;BATCH_RETURN&gt;
    &lt;RESPONSE&gt;
      &lt;DATETIME&gt;2017-04-20T20:27:15Z&lt;/DATETIME&gt;
      &lt;BATCH_LIST&gt;
        &lt;BATCH&gt;
          &lt;CODE&gt;1921&lt;/CODE&gt;
          &lt;TEXT&gt;No Hosts Queued for Purging&lt;/TEXT&gt;
        &lt;/BATCH&gt;
      &lt;/BATCH_LIST&gt;
    &lt;/RESPONSE&gt;
  &lt;/BATCH_RETURN&gt;
  </code></pre>
  
  <p>I get the following error when using xmlstarlet:</p>
  
  <pre><code>failed to load external entity "https://qualysapi.qualys.com/api/2.0/batch_return.dtd"
  TYPE BATCH_RETURN SYSTEM "https://qualysapi.qualys.com/api/2.0/batch_return.dtd"
                                                                                 ^
  </code></pre>