Use bitmask and bitwise boolean operations. 
fisher% perl -e 'my $byte=129; my $first5=$byte&0xf8; printf "%08b, %d
+\n", $byte, $first5;'
10000001, 128

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In reply to Re: first 5 bits and last 3 bits by fisher
in thread first 5 bits and last 3 bits by pashanoid

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