Search with content exclusion

  • I am a casual user of N++ and, definitely, not familiar with all of its functionality.
    One way I would like to use N++ is search for patterns, but excluding sub-results.
    An example would be to look for, let’s say, a “RESULTVALUE=” in a logfile, but wanting to ONLY see non-zero results.
    In grep this would look something like:
    grep “RESULTVALUE=” | grep -v “RESULTVALUE=0”
    Is this possible in N++ and, if so, how?

  • Hi @Peter-Cohen

    Sure is possible. In order to accomplish your wish, search or mark with the following regular expressión


    Put the caret at the very beginning of the document, select the Regular Expression mode and click on Find Next, Find All in Current Document or Mark All as appropriated.

    Take care and have fun!

  • Hello astrofista,
    Thanks for putting me on the path to a solution.
    However, using your expression, I did not get the result I want.
    Using the table below, I ONLY want to find line 2 & 4.
    Using RESULTVALUE=(?=") gets me nothing.
    Using RESULTVALUE=(?=0) gets me all the zero (0) values.
    Is there a way to specify (?=Not 0)


  • @Peter-Cohen

    For “not zero”, try (?!0), so RESULTVALUE=(?!0) for your need.

  • Hi @Peter-Cohen

    You’re welcome. My regex says: match every RESULTVALUE= that is followed by a quote ", as I read your example. However it seems that I misunderstood your needs.

    Try this other regex instead:


    It will match every ‘RESULTVALUE=’ that is not followed by 0".

    Hope it’s fine now.

  • @astrosofista

    I really don’t think that " enter into the OP’s need at all.
    He was just using the quotes because he’s familiar with doing it when using grep, I think.

  • @Alan-Kilborn

    Good point :)


    Remove the quote from my regex if not needed.

  • @astrosofista said in Search with content exclusion:

    Remove the quote from my regex if not needed.

    At which point, doesn’t it become the same as MY regex? ;-)

  • Gentlemen,
    Thank you very much, RESULTVALUE=(?!0) did the trick.
    Sorry if I confused you - I was even more confused.
    This is definitely very powerful and useful (and tricky).

  • BTW - would it be impertinent from me to ask WHY/HOW this works?
    I am trying to decipher (?!0) and - admittedly - don’t understand what it actually stands for.
    Interestingly, I changed one of the lines to:
    RESULTVALUE=090 and now the search doesn’t find it, I suspect because it starts with a 0.

  • @Peter-Cohen said in Search with content exclusion:

    would it be impertinent from me to ask WHY/HOW this works?

    Of course not.

    The construct (?!) is a negative lookahead assertion.
    It means that at the current position, for there to be a composite match, whatever ... is, cannot be a match for the data (or the overall match fails).

    Traditionally, in computer science, ! means “not”.

    So in an Englishy way, the expression RESULTVALUE=(?!0) means:

    match RESULTVALUE= literally, and then insist that the next character is not 0 for a match to be possible.

    But the way (?!0) is used here, it precludes 090 from matching (the search stops trying to match at the first 0).

    If something is unclear, post again.

    You can find many more details about the concepts begun here, in THIS thread.

  • Hello @Alan-Kilborn - going through a crash course here.
    BTW - I used to be a computer programmer in a previous life, but this, definitely, is new territory for me :-|
    I will definitely have to read up on this - thanks for the link.

  • @Peter-Cohen said in Search with content exclusion:

    RESULTVALUE=090 and now the search doesn’t find it, I suspect because it starts with a 0.

    You got it, that’s correct.

    However that doesn’t mean that you cannot match a number that starts with a 0. The following regex will match RESULTVALUE=090 but not RESULTVALUE=0 or RESULTVALUE=", that is, when RESULTVALUE= is followed by any other symbol than a number:


    Hope this helps.

  • Holy cow - let me play with this - thanks.

  • Hi, @peter-cohen, @astrosofista, @alan-kilborn and All,

    Let’s imagine that we want to search for any integer or floating decimal number, different of any zero syntax, when it follows the RESULTVALUE= string, with this exact case. Then a possible regex, expressed with the free-spacing mode ( (?x) ) could be :

    (?x-i)  RESULTVALUE=  \K  [+-]?  (  (?! 0 \. 0? \D | 0 [^\d.] )  \d+  ( \. \d* )?  |  \.  (?! 0 \D ) \d+  )

    • Paste the text, below, in a N++ new tab
        RESULTVALUE=              No               ResultValue=              No                                      
        RESULTVALUE=.             No               ResultValue=.             No                 .               No   
        RESULTVALUE=,             No               ResultValue=,             No                 ,               No   
        RESULTVALUE=ABC           No               ResultValue=ABC           No                 ABC             No   
        RESULTVALUE=0             No               ResultValue=0             No                 0               No   
        RESULTVALUE=-0            No               ResultValue=-0            No                 -0              No   
        RESULTVALUE=+0            No               ResultValue=+0            No                 +0              No   
        RESULTVALUE=.0            No               ResultValue=.0            No                 .0              No   
        RESULTVALUE=-.0           No               ResultValue=-.0           No                 -.0             No   
        RESULTVALUE=+.0           No               ResultValue=+.0           No                 +.0             No   
        RESULTVALUE=0.            No               ResultValue=0.            No                 0.              No   
        RESULTVALUE=+0.           No               ResultValue=+0.           No                 +0.             No   
        RESULTVALUE=-0.           No               ResultValue=-0.           No                 -0.             No   
        RESULTVALUE=0.0           No               ResultValue=0.0           No                 0.0             No   
        RESULTVALUE=+0.0          No               ResultValue=+0.0          No                 +0.0            No   
        RESULTVALUE=-0.0          No               ResultValue=-0.0          No                 -0.0            No   
        RESULTVALUE=0.00120       Yes              ResultValue=0.00120       No / Yes           0.00120         No   
        RESULTVALUE=0.00123       Yes              ResultValue=0.00123       No / Yes           0.00123         No   
        RESULTVALUE=0.12300       Yes              ResultValue=0.12300       No / Yes           0.12300         No   
        RESULTVALUE=0.42          Yes              ResultValue=0.42          No / Yes           0.42            No   
        RESULTVALUE=.71           Yes              ResultValue=.71           No / Yes           .71             No   
        RESULTVALUE=2             Yes              ResultValue=2             No / Yes           2               No   
        RESULTVALUE=5.            Yes              ResultValue=5.            No / Yes           5.              No   
        RESULTVALUE=6.8           Yes              ResultValue=6.8           No / Yes           6.8             No   
        RESULTVALUE=007.1         Yes              ResultValue=007.1         No / Yes           007.1           No   
        RESULTVALUE=091           Yes              ResultValue=091           No / Yes           091             No   
        RESULTVALUE=+0.00120      Yes              ResultValue=+0.00120      No / Yes           +0.00120        No   
        RESULTVALUE=+0.00123      Yes              ResultValue=+0.00123      No / Yes           +0.00123        No   
        RESULTVALUE=+0.12300      Yes              ResultValue=+0.12300      No / Yes           +0.12300        No   
        RESULTVALUE=+0.42         Yes              ResultValue=+0.42         No / Yes           +0.42           No   
        RESULTVALUE=+.71          Yes              ResultValue=+.71          No / Yes           +.71            No   
        RESULTVALUE=+2            Yes              ResultValue=+2            No / Yes           +2              No   
        RESULTVALUE=+5.           Yes              ResultValue=+5.           No / Yes           +5.             No   
        RESULTVALUE=+6.8          Yes              ResultValue=+6.8          No / Yes           +6.8            No   
        RESULTVALUE=+007.1        Yes              ResultValue=+007.1        No / Yes           +007.1          No   
        RESULTVALUE=+091          Yes              ResultValue=+091          No / Yes           +091            No   
        RESULTVALUE=-0.00120      Yes              ResultValue=-0.00120      No / Yes           -0.00120        No   
        RESULTVALUE=-0.00123      Yes              ResultValue=-0.00123      No / Yes           -0.00123        No   
        RESULTVALUE=-0.12300      Yes              ResultValue=-0.12300      No / Yes           -0.12300        No   
        RESULTVALUE=-0.42         Yes              ResultValue=-0.42         No / Yes           -0.42           No   
        RESULTVALUE=-.71          Yes              ResultValue=-.71          No / Yes           -.71            No   
        RESULTVALUE=-2            Yes              ResultValue=-2            No / Yes           -2              No   
        RESULTVALUE=-5.           Yes              ResultValue=-5.           No / Yes           -5.             No   
        RESULTVALUE=-6.8          Yes              ResultValue=-6.8          No / Yes           -6.8            No   
        RESULTVALUE=-007.1        Yes              ResultValue=-007.1        No / Yes           -007.1          No   
        RESULTVALUE=-091          Yes              ResultValue=-091          No / Yes           -091            No   

    • Open the Mark dialog ( Ctrl + M )

      • SEARCH (?-i)RESULTVALUE=\K[+-]?((?!0\.0?\D|0[^\d.])\d+(\.\d*)?|\.(?!0\D)\d+)

      • Tick the Purge for each search option

      • Tick the Wrap around option

      • Select the Regular expression search mode

      • Click on the Mark All button

    => Only numbers, located after the RESULTVALUE= string, with this case, and strictly different from 0, should be highlighted in red

    Now, if you modify the regex as (?i)RESULTVALUE=\K[+-]?((?!0\.0?\D|0[^\d.])\d+(\.\d*)?|\.(?!0\D)\d+), the numbers, located after the string ResultValue= are also highlighted !

    Peter, this example is simply provided to show the powerful of regular expressions. Of course, you cannot fully understand that example, by now. Just execute the regexes to get the results and, from the @alan-kilborn’s link, try to learn the basic regex features !

    Best Regards,


  • Good afternoon @Folks,
    I am off to regex school, although, admittedly, these last expressions do make my head spin @Exorcist :-)

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