Print numbers, upper-lower case letters separately in perl - regex

Question

I have a list like:
DD2aaQQmmm
AA34DDmm
And i want to print the upper case, the lower case and the numbers separately, so it would be like:
DDQQ aammm 2
AADD mm 34
How should I do this in perl, using regex?
I have tried for the upper case this:
#!/usr/bin/perl
my #array = <>;
chomp(#array);
foreach (#array){
if ($_ = ~ /([A-Z][a-z])/){
print $_ "\n"
}
}
But this only prints out the words starts with upper case.

Answer 1

The task is quite simple -- separate the wheat from the chaff
use strict;
use warnings;
use feature 'say';
while(my $line = <DATA>) {
my #out;
$out[0] = $line =~ s/[^A-Z]//gr;
$out[1] = $line =~ s/[^a-z]//gr;
$out[2] = $line =~ s/[^0-9]//gr;
say join(' ', #out);
}
__DATA__
DD2aaQQmmm
AA34DDmm
Output
DDQQ aammm 2
AADD mm 34
Of cause the final script can read from pipe or file given on command line
use strict;
use warnings;
use feature 'say';
while(<>) {
my #out;
$out[0] = s/[^A-Z]//gr;
$out[1] = s/[^a-z]//gr;
$out[2] = s/[^0-9]//gr;
say join(' ', #out);
}

Answer 2

Another way to go is to use tr operator.
use Modern::Perl;
while(my $str = <DATA>) {
chomp $str;
my #out;
push #out, $str =~ tr/A-Z//cdr;
push #out, $str =~ tr/a-z//cdr;
push #out, $str =~ tr/0-9//cdr;
say "#out";
}
__DATA__
DD2aaQQmmm
AA34DDmm
Output:
DDQQ aammm 2
AADD mm 34
tr is about 6 times quicker than s///, here is a benchmarck:
use Modern::Perl;
use Benchmark qw(:all);
my $str = "DD2aaQQmmm";
my $count = -3;
cmpthese($count, {
'tr' => sub {
my #out;
push #out, $str =~ tr/A-Z//cdr;
push #out, $str =~ tr/a-z//cdr;
push #out, $str =~ tr/0-9//cdr;
},
'subst' => sub {
my #out;
$out[0] = $str =~ s/[^A-Z]//gr;
$out[1] = $str =~ s/[^a-z]//gr;
$out[2] = $str =~ s/[^0-9]//gr;
},
});
Output:
Rate subst tr
subst 58165/s -- -84%
tr 357629/s 515% --

Answer 3

Polar Bears solution is absolutely correct - but needs perl 5.14+ Here is a simple workaround for older perl versions.
use strict;
use warnings;
while(my $line = <DATA>) {
my #out = ($line, $line, $line);
$out[0] =~ s/[^A-Z]//g;
$out[1] =~ s/[^a-z]//g;
$out[2] =~ s/[^0-9]//g;
print join(' ', #out) . "\n";
}
__DATA__
DD2aaQQmmm
AA34DDmm