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Re: Using grep and glob to find directories containing file

by BrowserUk (Pope)
on Feb 03, 2013 at 14:52 UTC ( #1016827=note: print w/ replies, xml ) Need Help??


in reply to Using grep and glob to find directories containing file

grep will return the input (eg."dir1", "dir2", "dir3"), if the glob returns true. Perhaps you want map.


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Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
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Comment on Re: Using grep and glob to find directories containing file
Re^2: Using grep and glob to find directories containing file
by Anonymous Monk on Feb 03, 2013 at 15:09 UTC
    I thought grep will *only* return the elements of the array for which the first expression is true. Since the first expression glob("$_/f*") is only true for 'dir1', it should only return that element of the directory list (even though glob returns 3 files in that directory). The glob finds no elements in the other 2 directories, so it should be undefined which would evaluate as false.

    I don't understand why the elements of glob("$_/f*") returned for the first directory entry seemingly spill over to subsequent directories in the (implicit) grep iteration.
      Since the first expression glob("$_/f*") is only true for 'dir1', it should only return that element of the directory list (even though glob returns 3 files in that directory).

      You are missing the fact that grep puts the glob in a scalar context, and that makes it act as an iterator:

      In scalar context, glob iterates through such filename expansions, returning undef when the list is exhausted.

      With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'
      Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
      "Science is about questioning the status quo. Questioning authority".
      In the absence of evidence, opinion is indistinguishable from prejudice.

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