How to find two or more non-consecutive tabs in a line?
guy038 last edited by
Fundamentally, the new Alan’s solution and mine give the same right results, i.e. to match any non-empty line which does not contain a tabulation character !
By the way, we, both, forget to add the leading in-line-modifier
(?-s)to be sure that, even you previously ticked the
. matches newlineoption, the regex engine will suppose that any
.char does match a single standard character, only !
So, our two solutions should be :
However, note that the logic, underlying these
2regular expressions, is a bit different :
In the Alan’s regex, from beginning of line (
^), the regex engine matches for one or more standard characters, till the end of line (
$), ONLY IF each standard character encountered is not a tabulation character, due to the negative look-ahead
(?!\t), located right before the
In the Guy’s regex, the regex engine matches for all the standard characters of a line, (
^.+), ONLY IF ( implicitly at beginning of line ) it cannot find a tabulation character further on, at any position of current line, due to the negative look-ahead
I did a test with a file of
2,500,000lines, half of which contained 1 tabulation character and, clearly, the Alan’s version is faster ! (
2 mn 15 sfor Alan instead of
5mnfor my version )