----- Original Message -----
From: "Dermot" <paik...@googlemail.com>
Newsgroups: perl.beginners
To: "John W. Krahn" <jwkr...@shaw.ca>
Cc: "Perl Beginners" <beginners@perl.org>
Sent: Friday, November 27, 2009 12:29 PM
Subject: Re: a simple question about the line
2009/11/27 John W. Krahn <jwkr...@shaw.ca>:
Hello,
$ echo "12
23
34
45
56
67
78" | perl -lpe'$\=--$|?$,:$/'
1223
3445
5667
78
For the benefit of this Luddite, please explain?
Dp.
--$| toggles between 1 and 0. It is this variable's behavior when (--$| or
$|--)
$| is initially 0. (NOTE: this behavior doesn't happen with ++$| or
$|++).
-l chomps the line input and, for when --$| == 1, prints with $\ = $,
($, is by default the empty string). When --$| == 0, prints with $\
= $/
($/ is by default = "\n").
-p applies 'print()' as the last statement in the implicit 'while(
... )' loop
So. in effect, on the first line in, chomps the line. Then, since $|==1 in
the first
iteration, prints with a line end equal to $, (by default, the empty
string).
In the next line, $| will equal 0, so the print will end with $/ (default
value of "\n")
Chris
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