Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

how do I do a regex that adds a character in s tring every "x" number of characters.

ie: 

$string='abchijk';
while ($string =~ s/(\w{2})(.*)$/$1\|$2/) {
print "$string\n";
}

should print:
ab|chijk
ab|ch|ijk
ab|ch|ij|k

[download]

s/pre/code/ tags - dvergin 2002-04-29

Replies are listed 'Best First'.
Re: regex multiple times
by Zaxo (Archbishop) on Apr 30, 2002 at 02:09 UTC

    One way, with regexes, is:

    $string =~ s/(..)/$1|/g;

    [download]
    If the string is read from a handle, there is a neat trick using a reference to an integer for $/:
    my $string;
{
    local $/ = \2;
    my @pairs = <FOO>;
    $string = join '|',  @pairs;
}

    [download]
    It would be good if one of the modules tieing handles to strings honored $/ accurately enough to us this on a string, but afaik they don't.

    After Compline,
    Zaxo

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Re: regex multiple times
by Cyrnus (Monk) on Apr 30, 2002 at 02:30 UTC
    You were close. This will do what you intended. 
    $string='abchijk';
while ($string =~ s/(\w{2})(\w)/$1\|$2/) {
    print "$string\n";
}

    [download]
    When you were using (.*) it was matching the '|'

    John
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Re: regex multiple times
by abaxaba (Hermit) on Apr 30, 2002 at 03:07 UTC
    howabout -- 
    (@parts) = $string=~/(\w{2})/g;
print join ("|",@parts);

    [download]
    ÅßÅ×ÅßÅ
    "It is a very mixed blessing to be brought back from the dead." -- Kurt Vonnegut
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