Text Processing using regular expression

Specification

given a file like this,there are three field divided by

abc-efg012.123. |one|two
second-of WGF|two|three
second-of||three
forth-of|one|

write a perl script,

for the first field, extract from the beginning untill a . or space.
exchange the place of the second the third part

Solution 1

use v5.14;
my @input;

while(<DATA>) {
    chomp;
    my @fields = split /\|/;
    $fields[0] =~ /([^\.\s]+)/;
    $fields[0] = $1;
    push @input, \@fields
}
say "$_->[0]|$_->[2]|$_->[1]" for (reverse @input);
 __DATA__
abc-efg012.123. |one|two
second-of WGF|two|three
second-of||three
forth-of|one|

Solution 2

use regular expression

my @input;
while(<DATA>) {
    s/([^\.\s]+).*?(?=\|)/$1/;
    s/\|(.*)\|(.*)\Z/\|$2\|$1/;
    push @input, $_;
}
print for (reverse @input);
__DATA__
abc-efg012.123. |one|two
second-of WGF|two|three
second-of||three
forth-of|one|