Re: Splitting up a string by lengths

The most efficient solution is:

my ($y, $m, $d) = unpack('a4a2a2', $str);
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But the following solutions also work:

my $y = substr($str, 0, 4);
my $m = substr($str, 4, 2);
my $d = substr($str, 6, 2);
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my ($y, $m, $d) = $str =~ /(.{4})(.{2})(.{2})/;
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(Update:)

or the sillier

$str =~ /(.{4})/g;  my $y = $1;
$str =~ /(.{2})/g;  my $m = $1;
$str =~ /(.{2})/g;  my $d = $1;
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To convert the returned strings into numbers (which removes the leading 0s), prepend map { 0+$_ }. For example,

my ($y, $m, $d) = map { 0+$_ } unpack('a4a2a2', $str);
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You can always pad with 0s later:

printf("%04d/%02d/%02d\n", $y, $m, $d);
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$formatted = sprintf("%04d/%02d/%02d", $y, $m, $d);
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Comment on Re: Splitting up a string by lengths Select or Download Code

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Re^2: Splitting up a string by lengths by polettix (Vicar) on Jul 25, 2005 at 17:41 UTC
I'd avoid the sillier approach, it may fail miserably for badly formatted input strings: `#!/usr/bin/perl use strict; use warnings; my $str = '2004'; $str =~ /(.{4})/g; my $y = $1; $str =~ /(.{2})/g; my $m = $1; $str =~ /(.{2})/g; my $d = $1; print "$y-$m-$d\n"; __END__ 2004-2004-20` [download] Flavio perl -ple'$_=reverse' <<<ti.xittelop@oivalf Don't fool yourself.	[reply] [d/l]