Re^3: Break one liner command line script after first match

Hi,
Be aware of the subtle difference between:

perl -ne'/(data)/ && print $1 and last' file.txt

perl -ne'/(data)/ && print $1 && last' file.txt
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Of course, I saw the subtle difference, and how you used

.. print ($1) ...
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the parentheses which is effectively the same thing if "and" is used instead of "&&"
check this:

Using

perl -MO=Deparse -ne'/(data)/ && print $1 && last' file.txt
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you gets:

LINE: while (defined($_ = <ARGV>)) {
    print $1 && last if /(data)/;
}
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but using

perl -MO=Deparse -ne'/(data)/ && print ($1) && last' file.txt
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gives:

LINE: while (defined($_ = <ARGV>)) {
    last if /(data)/ and print $1;
}
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Which is same as this:

perl -MO=Deparse -ne'/(data)/ && print $1 and last' file.txt
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LINE: while (defined($_ = <ARGV>)) {
    last if /(data)/ and print $1;
}
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If you tell me, I'll forget.
If you show me, I'll remember.
if you involve me, I'll understand.
--- Author unknown to me

Comment on Re^3: Break one liner command line script after first match Select or Download Code

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Re^4: Break one liner command line script after first match by McA (Priest) on Oct 30, 2013 at 13:32 UTC
I was sure that you know the difference. ;) I just wanted to point it out for the interested readers. And in the result we get just much more interesting stuff from you. ++ for that. Thank you. Best regards McA	[reply]