Try 

perl -wne 'BEGIN {$b= "";} if (/\47[1-4]\47/) {$b= $_.$b;} elsif (/\47
+[5]\47/) {print $b, $_; $b= "";} else {print;}'

[download]

I'm not sure if it does what you want.

In reply to Re: sed to perl conversion by ambrus
in thread sed to perl conversion by NovMonk

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