That gives warnings and extra <br>s when there aren't five lines yet. 

>perl -we"@lines = qw( a b c ); print join '<br>', @lines[0..4];
Use of uninitialized value in join or string at -e line 1.
Use of uninitialized value in join or string at -e line 1.
a<br>b<br>c<br><br>

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Also, given $html_doc = "a new set - line 1 {br} $html_doc", you're short a br when there are five lines.

In reply to Re^2: truncating a text file by ikegami
in thread truncating a text file by dankichi

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