How to find two or more non-consecutive tabs in a line?
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Hi, @glossar, @alan-kilborn, @meta-chuh, @peterjones and All,
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 :
Alan :
(?-s)^((?!\t).)+$Guy :
(?-s)(?!.*\t)^.+
However, note that the logic, underlying these
2regular expressions, is a bit different :-
In the Alan’s regex, from beginning of line (
^), the regex engine matches for one or more standard characters, till the end of line ($), ONLY IF each standard character encountered is not a tabulation character, due to the negative look-ahead(?!\t), located right before the.regex character -
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(?!.*\t)
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 of5mnfor my version )BR
guy038
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