span class="op">(</span></span>
<span>  <span class="va">string</span>,</span>
<span>  intern <span class="op">=</span> <span class="cn">NULL</span>,</span>
<span>  ignore.stderr <span class="op">=</span> <span class="cn">NULL</span>,</span>
<span>  Sys_ignore.stdout <span class="op">=</span> <span class="cn">FALSE</span>,</span>
<span>  Sys_wait <span class="op">=</span> <span class="cn">TRUE</span>,</span>
<span>  Sys_input <span class="op">=</span> <span class="cn">NULL</span>,</span>
<span>  Sys_show.ou