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Re^3: More complicated regular expression?

by jaldama (Acolyte)
on Jan 26, 2012 at 18:21 UTC ( #950186=note: print w/ replies, xml ) Need Help??


in reply to Re^2: More complicated regular expression?
in thread More complicated regular expression?

Last question. What if the output instead of

Using domain server: Name: 8.8.8.8 Address: 8.8.8.8#53 Aliases: google.com has address 74.125.113.147
Comes out on one line like this:
$ host google.com 8.8.8.8 google.com A 74.125.113.99
My previous matching idea still cuts off the last digit. I thought using javafan's and searching for A
/A (\S+)/ and do_something($1);
Might work but it doesn't seem to. Is there an issue because of the spacing?


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Re^4: More complicated regular expression?
by Xiong (Hermit) on Jan 26, 2012 at 20:00 UTC

    If you change the game, you change the win. Tell us all of the contexts in which you hope to find your desired string.

    JavaFan's regex worked for your first example because you showed a short, unambiguous introduction to your goal string. /\S/ matches on non-whitespace; there's no whitespace in your first example between /has address / and your goal string. Note that the single space following the last 's' is included in the regex.

    Matching on /A/ doesn't work in your second example because the introduction to your goal string is not /A/; it's /A\s+/. This would not be real smart; it's not likely to be unique.

    Formulate your problem clearly. Prepare a short list of all the various forms of input data you expect to see; and for each form, desired output. Then it is easy, even possible, to construct a solution.

    I'm not the guy you kill, I'm the guy you buy. —Michael Clayton
Re^4: More complicated regular expression?
by polettix (Vicar) on Jan 28, 2012 at 12:34 UTC
    my ($address) = m{\s+ (?: address | A) \s+ (\S+)}x;

    I still wonder why host should change its output format, anyway.

    perl -ple'$_=reverse' <<<ti.xittelop@oivalf

    Io ho capito... ma tu che hai detto?

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