You are assuming the wrong association of operators, and possibly their meaning. Numbering your tests cases:
(1) $0 ~/[Ss]ystem/ checks if "$0 matches /RE/". The || /puls/ condition is not even tested: it is "short-circuited" because the overall condition is already known to be true.
(2) The && checks if both conditions are true, and matches only one line.
(3) The combined RE (two alternative cases with |) matches two lines.
(4) This matches both the stored lines that contain System.
(5) This matches nothing. It tests a stored line from the array, but the '/puls/' tests the value in $0 after you have run off the end of the file -- it does not refer to k1[i]. $0 would still contain the last line of the file, and I conjecture that the complete input file has no such line at the end. The && requires both conditions to be true, so no line matches.
(6) Is a duplicate of (5).
(7) is a duplicate of (2).
$0 ~/[Ss]ystem/checks if "$0 matches /RE/". The|| /puls/condition is not even tested: it is "short-circuited" because the overall condition is already known to be true.The
&&checks if both conditions are true, and matches only one line.The combined RE (two alternative cases with
|) matches two lines.This matches both the stored lines that contain
System.This matches nothing. It tests a stored line from the array, but the '/puls/' tests the value in $0 after you have run off the end of the file -- it does not refer to k1[i]. $0 would still contain the last line of the file, and I conjecture that the complete input file has no such line at the end. The
&&requires both conditions to be true, so no line matches.Is a duplicate of (5).
is a duplicate of (2).
