C:\tmp\files>perl -nE" $first=/PATTERN1/; $last=/PATTERN3/; if ( $first..$last) { @o=() if $first; push @o,$_; say @o if $last }" input2
PATTERN1 SOME INFO

TEXT4

TEXT5

TEXT6 PATTERN3 SOME INFO

PATTERN1 SOME INFO

TEXT4

TEXT5

TEXT6 PATTERN3 SOME INFO