Perl의 아름다움에 빠져보아요. -.,-;

Perl vs. Python vs. Ruby

주어진 문제

다음과 같이 탭으로 구분되고 큰따옴표로 둘러싸인 컬럼들이 있다. 이 중에서 CONTACTME가 1인 줄만 뽑아서 SKUTITLE을 기준으로 정렬해서 출력하라. 각 컬럼값 자체에는 큰따옴표가 없다고 가정한다.

"EMAIL"	"CONTACTME"	"SKUTITLE"
"foo2@bar.com"	"1"	"Product3"
"foo@bar.com"	"0"	"Product1"
"foo1@bar.com"	"1"	"Product2"

다양한 Perl 코드

원저자의 코드는 좀 장황하다.

#!/usr/bin/perl -w

use strict;

my @records = ();

foreach my $line ( <> )
{
    my @record = map {s/"//g; $_} split("\t", $line);
    push(@records, \@record);
}

my $EMAIL = 0;
my $CONTACTME = 1;
my $SKUTITLE = 2;

my @contactRecords = ();
foreach my $r ( @records )
{
    push(@contactRecords, [$$r[$SKUTITLE], $$r[$CONTACTME], $$r[$EMAIL]]);
}

@contactRecords = sort {$$a[0] cmp $$b[0]} @contactRecords;
@contactRecords = grep($$_[1] eq "1", @contactRecords);

foreach my $r ( @contactRecords )
{
    print join("\t", @$r), "\n";
}

나도 한번 만들어 봤다.

#!/usr/bin/perl
use constant EMAIL => 0;
use constant CONTACTME => 1;
use constant SKUTITLE => 2;
my @dat;
while(<>){
	s/"//g;
	@_ = split /[\t\r\n]/;
	next unless($_[CONTACTME] eq "1");
	push @dat, "$_[SKUTITLE]\t$_[CONTACTME]\t$_[EMAIL]\n";
}
print sort @dat;

음.. 조금 더 내려가니 괜찮은 작품들이 보이기 시작한다.

#!/usr/bin/perl

use strict;
use warnings;

my @records;

push @records, [ (/"(.*?)"/g)[0,1,2] ] while <>;

($\,$,)=("\n","\t");

print "@$_" for
sort { $a->[0] cmp $b->[0] }
  grep $_->[1] eq '1', @records;

앗! 정신이 혼미해지는걸...

#!/usr/bin/perl
my @recs =  sort { $a->[0] cmp $b->[0] } grep { $_->[1] eq '1' }
	map { my @r = split /\t/; [map { s/"//g; $_ } @r[2, 1, 0]] } <>;
print join("\t", @$_), "\n" for @recs;

안 돌아가길래 조금 손 봤지만 이것도 비슷하다.

#!/usr/bin/perl
($,, $\) = ("\t", "\n");
print @$_ foreach
	sort { $a->[0] cmp $b->[0]   }
	grep { $_->[1] eq "1"        }
	map  { [@$_[2,1,0]]          }
	map  { s/"//g for @$_; [@$_] }
	map  { [split /[\t\r\n]/]    }
	<>;

그래서 나의 결론은 버킹검이다.

#!/usr/bin/perl
print join("\t", @$_), "\n" for
	sort { $a->[0] cmp $b->[0]   }
	grep { $_->[1] eq '1'        }
	map  { [@$_[2,1,0]]          }
	map  { s/"//g for @$_; [@$_] }
	map  { [split /[\t\r\n]/]    }
	<>;

한줄로 끝내기!

perl -e 'print join("\t", @$_), "\n" for sort { $a->[0] cmp $b->[0] } grep { $_->[1] eq '1' } map { [@$_[2,1,0]] } map { s/"//g for @$_; [@$_] } map { [split /[\t\r\n]/] } <>' < data.txt

이걸 단번에 한줄로 코딩하면 인간일까?

sed 's/"\([^"]*\)"	"\([^"]*\)"	"\([^"]*\)"/\3	\2	\1/; /	0	/d' data.txt | sort

gsed -n 's/"\([^"]*\)"\t"\([^"]*\)"\t"\([^"]*\)"/\3"\2"\1/
/"0"/d

################################################################################
# GNU sed sort by Greg Ubben http://sed.sourceforge.net/grabbag/scripts/sodelnum.sed
# Modified by Huidae Cho for GNU sed 4.0.9
H
$!b
s/.*/° !"#$%\&'"'"'()*+,-.\/0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~/
H
g

:sort
s/\(\n\([^°\n]*\)\([^°\n]\)[^°\n]*\)\(\n.*\)\?\(\n\2\([^°\n]\)[^°\n]*\)\(\n.*°.*\6.*\3\)/\5\1\4\7/
t sort
# end of sort
################################################################################

s/^\n\(.*\n\)°.*$/\1/
s/"/\t/g

:print
P
s/[^\n]*\n//
/./b print' data.txt

gsed -n 's/"\([^"]*\)"\t"\([^"]*\)"\t"\([^"]*\)"/\3"\2"\1/; /"0"/d; H; $!b; s/.*/° !"#$%\&'"'"'()*+,-.\/0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~/; H; g; :sort; s/\(\n\([^°\n]*\)\([^°\n]\)[^°\n]*\)\(\n.*\)\?\(\n\2\([^°\n]\)[^°\n]*\)\(\n.*°.*\6.*\3\)/\5\1\4\7/; t sort; s/^\n\(.*\n\)°.*$/\1/; s/"/\t/g; :print; P; s/[^\n]*\n//; /./b print' data.txt