omment>%&nbsp;Check&nbsp;if&nbsp;file&nbsp;of&nbsp;given&nbsp;name&nbsp;exists.&nbsp;If&nbsp;not&nbsp;then&nbsp;prints</span><br>
<span class=comment>%&nbsp;error.</span><br>
<span class=comment>%&nbsp;</span><br>
<br>
attempts=0;<br>
found&nbsp;=&nbsp;<span class=stack>exist</span>(fname);<br>
<span class=keyword>while</span>&nbsp;attempts&nbsp;&lt;&nbsp;5&nbsp;&&&nbsp;~found<br>
&nbsp;&nbsp;found&nbsp;=&nbsp;<span class=stack>exist</span>(fname);<br>
&nbsp;&nbsp;attempts&nbsp;=&nbsp;attempts+1;&nbsp;&nbsp