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Re: Searching with Boolean Expressions

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  • diodeom
    ... Possibly for many tasks the good old findstr could be a straightforward alternative, where any needed filtering is either piped to another cmd or delegated
    Message 1 of 14 , May 16, 2011
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      Flo wrote:
      >
      > (...) Say, we want to find all files (names only) matching
      > the Boolean expression
      >
      > 'apples NOT (oranges OR bananas)'
      >

      Possibly for many tasks the good old findstr could be a straightforward alternative, where any needed filtering is either piped to another cmd or delegated to cozy string manipulations of NoteTab/PCRE.

      To address the given Boolean case (that I have a really hard time imagining in practical application :), here's a sample compromise (with superfluous refinements left out for clarity):

      ^!ChDir E:\Notetab\Documents
      ^!InsertSelect ^$GetOutput(cmd.exe /c findstr "apples" *.txt |findstr /v "oranges bananas")$
      ^$GetDocListAll("^[^:]++";$0\r\n)$

      BTW, findstr is no slouch when it comes to basic RegEx searches through piles of files -- and it's not limited to plain text either.
    • flo.gehrke
      ... diodeom, Thanks for your pointing out FINDSTR and your clip! In the past, we discussed many aspects of FINDSTR as an alternative to Search Disk. In my
      Message 2 of 14 , May 17, 2011
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        --- In ntb-clips@yahoogroups.com, "diodeom" <diomir@...> wrote:
        >
        > Possibly for many tasks the good old findstr could be a
        > straightforward alternative...

        diodeom,

        Thanks for your pointing out FINDSTR and your clip!

        In the past, we discussed many aspects of FINDSTR as an alternative to Search Disk. In my database, the oldest record is from Jane, 7/31/2007, #16823. In case you are interested to follow those discussions you may start with #19253 for example.

        As an DOS-alternative to FINDSTR we also tested BFIND (#19276).

        But, finally, I think Agent Ransack has proved itself the most efficient tool for tasks like that.

        Testing your clip I get no correct result. I created six short files (name / contents, using 'aaaaa' etc not to mix it up with other files in that directory):

        anthony.txt / aaaaa
        bertha.txt / ooooo
        carla.txt / bbbbb
        elsa.txt / aaaaa ooooo
        fred.txt / ooooo bbbbb
        george.txt / aaaaa bbbbb

        According with those contents, I changed your clip to...

        ^!ChDir E:\Notetab\Documents
        ^!InsertSelect ^$GetOutput(cmd.exe /c findstr "aaaaa" *.txt |findstr /v "ooooo bbbbb")$
        ^$GetDocListAll("^[^:]++";$0\r\n)$

        This ends up in an empty document. Without the third line the output is...

        notetab.txt: (aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa()
        pcre.txt: aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
        pcre.txt: (aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa()

        What's wrong with that?

        Moreover -- as far as I can see -- FINDSTR offers no Boolean NOT and no parentheses. So how could you define an exclusion like 'x NOT (y OR z)'?

        Flo
      • flo.gehrke
        ... I have to add... A long aaaa... string is occurring in the two files that are being output (notetab.txt, pcre.txt). When moving those two files to
        Message 3 of 14 , May 17, 2011
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          --- In ntb-clips@yahoogroups.com, "flo.gehrke" <flo.gehrke@...> wrote:
          >
          > This ends up in an empty document. Without the third line the
          > output is...
          >
          > notetab.txt: (aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa()
          > pcre.txt: aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
          > pcre.txt: (aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa()

          I have to add...

          A long 'aaaa...' string is occurring in the two files that are being output (notetab.txt, pcre.txt). When moving those two files to another directory the output is completely empty. That is, no one of those six files is being selected whereas my Agent Ransack clips provide correct results.

          Flo
        • diodeom
          ... Try placing at least a carriage return at each end of your sample content. Without a wholesome line to work on findstr aaaaa by itself produces
          Message 4 of 14 , May 17, 2011
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            Flo wrote:
            >
            > Testing your clip I get no correct result. I created six short files (name / contents, using 'aaaaa' etc not to mix it up with other files in that directory):
            >
            > anthony.txt / aaaaa
            > bertha.txt / ooooo
            > carla.txt / bbbbb
            > elsa.txt / aaaaa ooooo
            > fred.txt / ooooo bbbbb
            > george.txt / aaaaa bbbbb
            >

            Try placing at least a carriage return at each end of your sample content. Without a wholesome line to work on findstr "aaaaa" by itself produces bunched-up results in one line (anthony.txt:aaaaaelsa.txt:aaaaa ooooogeorge.txt:aaaaa bbbbb). The subsequent findstr /v "ooooo bbbbb" attempts to locate a line that *does not* contain either "ooooo" or "bbbbb" -- and obviously fails.
          • Art Kocsis
            ... Ditto diodeom,. My development was interrupted at DOS and I was not even aware of FINDSTR. I have just used FIND and tried to work around its limitations.
            Message 5 of 14 , May 17, 2011
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              At 05/17/2011 04:29, you wrote:
              >--- In <mailto:ntb-clips%40yahoogroups.com>ntb-clips@yahoogroups.com,
              >"diodeom" <diomir@...> wrote:
              > > Possibly for many tasks the good old findstr could be a
              > > straightforward alternative...
              >diodeom,
              >
              >Thanks for your pointing out FINDSTR and your clip!
              Ditto diodeom,. My development was interrupted at DOS and I was not even aware
              of FINDSTR. I have just used FIND and tried to work around its limitations.
              I really
              need to spend some time looking over the XP commands!


              >Moreover -- as far as I can see -- FINDSTR offers no Boolean NOT and no
              >parentheses. So how could you define an exclusion like 'x NOT (y OR z)'?
              >Flo

              Flo, the answer your question re exclusions is logical equivalences.

              Your expression is actually: x AND (NOT (y OR z))

              The logical equivalent of "NOT (y OR z)" is "(NOT y) AND (NOT z)" so your
              expression becomes "x AND (NOT y) AND (NOT z)"

              So to accomplish your expression use FINDSTR three times - once to
              extract all "x"s, then to exclude all "y"s and finally to exclude all "z"s
              piping the output each time to the next step. Each pipe is like an AND.

              findstr x | findstr /v y | findstr /v z

              Namaste', Art
            • diodeom
              ... One can find lines not containing y s or z s in one shot by findstr /v y z where the space serves as OR in this notation. (By contrast, the following
              Message 6 of 14 , May 17, 2011
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                Art wrote:
                >
                > So to accomplish your expression use FINDSTR three times - once to
                > extract all "x"s, then to exclude all "y"s and finally to exclude all "z"s
                > piping the output each time to the next step. Each pipe is like an AND.
                >
                > findstr x | findstr /v y | findstr /v z
                >

                One can find lines not containing y's or z's in one shot by findstr /v "y z" where the space serves as OR in this notation. (By contrast, the following locates any lines without the literal "y z" string: findstr /v /c:"y z")
              • flo.gehrke
                ... diodeom, Yes, it s working with an additional CRNL. Also I can see the excluding effect now. May I tax your patience with another question? Does FINDSTR
                Message 7 of 14 , May 17, 2011
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                  --- In ntb-clips@yahoogroups.com, "diodeom" <diomir@...> wrote:

                  > Try placing at least a carriage return at each end of your
                  > sample content.

                  diodeom,

                  Yes, it's working with an additional CRNL. Also I can see the excluding effect now.

                  May I tax your patience with another question? Does FINDSTR allow even more complex Boolean expressions? A next stage would be to add a third criterion and to exclude combined criteria. Given another file henry.txt...

                  aaaaa
                  bbbbb
                  ccccc

                  Now we want to find 'aaaaa' but exclude files containing 'bbbbb' and 'ccccc'. With Agent Ransack, it works with...

                  'aaaaa NOT (bbbbb AND ccccc)'

                  The correct output will be anthony.txt, elsa.txt, and george.txt.

                  Thanks also to Art Kocsis! Possibly, Art has explained this already but I can't see how to formulate it with FINDSTR.

                  So far, I didn't test it with a greater amount of files. But I'm sure that FINDSTR would be faster -- at least for simple evaluations. On the other hand, Agent Ransack might provide an easier solution.

                  Flo
                • John Shotsky
                  It s funny, I never thought much about Findstr before I learned regex. Now, when I see what all it can do, I think there are a lot of possibilities in my
                  Message 8 of 14 , May 17, 2011
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                    It's funny, I never thought much about Findstr before I learned regex. Now, when I see what all it can do, I think there
                    are a lot of possibilities in my clips. Here's Microsoft's reference page:

                    http://technet.microsoft.com/en-us/library/bb490907.aspx



                    Regards,

                    John



                    From: ntb-clips@yahoogroups.com [mailto:ntb-clips@yahoogroups.com] On Behalf Of diodeom
                    Sent: Tuesday, May 17, 2011 07:50
                    To: ntb-clips@yahoogroups.com
                    Subject: [Clip] Re: Searching with Boolean Expressions





                    Art wrote:
                    >
                    > So to accomplish your expression use FINDSTR three times - once to
                    > extract all "x"s, then to exclude all "y"s and finally to exclude all "z"s
                    > piping the output each time to the next step. Each pipe is like an AND.
                    >
                    > findstr x | findstr /v y | findstr /v z
                    >

                    One can find lines not containing y's or z's in one shot by findstr /v "y z" where the space serves as OR in this
                    notation. (By contrast, the following locates any lines without the literal "y z" string: findstr /v /c:"y z")





                    [Non-text portions of this message have been removed]
                  • diodeom
                    ... Findstr operates in the context of individual lines within files, so to implement aaaaa NOT (bbbbb AND ccccc) for entire files, I d probably (at first
                    Message 9 of 14 , May 17, 2011
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                      Flo wrote:
                      >
                      > Now we want to find 'aaaaa' but exclude files containing 'bbbbb' and 'ccccc'. With Agent Ransack, it works with...
                      >
                      > 'aaaaa NOT (bbbbb AND ccccc)'
                      >

                      Findstr operates in the context of individual lines within files, so to implement "aaaaa NOT (bbbbb AND ccccc)" for entire files, I'd probably (at first glance) build the list of files containing "aaaaa" first:

                      findstr /m aaaaa

                      Then remove dupes, preserve the remnants for the last step and look among them for the first condition of exclusion:

                      findstr /m bbbbb

                      And then among the resulting list of files for the second condition:

                      findstr /m cccccc

                      Where I'd simply end up with any filenames to remove from the first list.

                      Achieving it with a single fancy long-winded call to cmd is probably not for the faint of heart, so I'd either make a .bat or just let Clip manipulate variables and act as glue between the blazing searches.

                      To answer your question, Flo, I don't see an AND provision within the Findstr itself, but command redirection operators (&, &&, | and ||) afford plenty of Boolean logic.
                    • Art Kocsis
                      Duh! I need more sleep. Or need to grow younger. I had just read that an hour earlier. In one eye and out the hole in my head!!! Art
                      Message 10 of 14 , May 17, 2011
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                        Duh! I need more sleep. Or need to grow younger.
                        I had just read that an hour earlier.
                        In one eye and out the hole in my head!!!

                        Art

                        At 05/17/2011 07:49, diodeom wrote:
                        >Art wrote:
                        > > So to accomplish your expression use FINDSTR three times - once to
                        > > extract all "x"s, then to exclude all "y"s and finally to exclude all "z"s
                        > > piping the output each time to the next step. Each pipe is like an AND.
                        > >
                        > > findstr x | findstr /v y | findstr /v z
                        >
                        >One can find lines not containing y's or z's in one shot by findstr /v "y
                        >z" where the space serves as OR in this notation. (By contrast, the
                        >following locates any lines without the literal "y z" string: findstr /v
                        >/c:"y z")
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