Re: A little regex help please!

More of the same, but

Lookahead not needed.
I think /(.*?)\n/ is slower than /([^\n]*)/.
local $/; is safer than undef $/;.
It's probably safer to search for "mailbox" followed by a number than for just a number.
Hardcoding the number's length is probably undesirable.

local $/;
my $text = <DATA>;

my ($number, $from) = $text =~ /mailbox (\d+).*?From:\s*([^\n]+)/;
[download]

It might be more efficient to replace the .*? with .*. Both will work.

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Re^2: A little regex help please! by japhy (Canon) on Jan 31, 2006 at 22:03 UTC
`/.?\n/` isn't really any slower, since it jumps to the closest newline it finds. The silly thing is the `?` in that regex. The `.?` in your regex WON'T match over the newlines, so you're missing an `/s` modifier I think. And since `[^\n]` IS `.`, I'd just write: `{ local $/; my ($num, $from) = <FILE> =~ m{ mailbox \s+ (\d+): \s+ From: \s* (.) }x; }` [download] Untested, but it seems to me that it should work properly, given the data from the OP. Jeff `japhy` Pinyan, P.L., P.M., P.O.D, X.S.: Perl, regex, and `perl` hacker How can we ever be the sold short or the cheated, we who for every service have long ago been overpaid? ~~ Meister Eckhart*	[reply] [d/l] [select]

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Re^2: A little regex help please!
by japhy (Canon) on Jan 31, 2006 at 22:03 UTC

/.*?\n/

?

.*?

/s

[^\n]

.

{
  local $/;
  my ($num, $from) = <FILE> =~ m{
    mailbox \s+ (\d+): \s+
    From: \s* (.*)
  }x;
}
[download]

Jeff japhy Pinyan, P.L., P.M., P.O.D, X.S.: Perl, regex, and perl hacker
How can we ever be the sold short or the cheated, we who for every service have long ago been overpaid? ~~ Meister Eckhart

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