I can only guess that the grep is matching more than one line for some of the elements in @isos20

Why are you guessing? Don't you know? If you don't even know if the problem exists, how can we help you?

And if the problem does exist, the way to verify it is to check the data, which we don't have.

I don't know why that would happen

There are two possibilities (assuming your actual code is correct. How can you "lose" a pair of //s when copy&pasting? You didn't C&P? Why not?):

  1. The file contains more than one line with the same identifier.

    You are not anchoring your regex to the the start of the line. Is it possible for a different identifier to appear someplace other than the beginning of the line?

  2. The array contains two or more copies of the same identifier.

    Have you checked the contents of the array?

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.

In reply to Re: grep of readline matching more lines than elements in array by BrowserUk
in thread grep of readline matching more lines than elements in array by bdorsey

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