pl - Swiss Army Knife of Perl One-Liners

Just one small script extends "perl -E" with many bells & whistles: Various
one-letter commands & magic variables (with meaningful aliases too) and more
nifty loop options take Perl programming to the command line.  List::Util is
fully imported.  Unless you pass a program on the command line, starts a
simple Perl Shell.

E(cho) 3 values, including 2 from "@A(RGV)".  And same for difficult values:

    pl 'e "Perl", @A' one liner
    pl 'e \"Perl", \@A, undef' one liner

Print up to 3 matching lines, resetting count (and "$.") for each file:

    pl -rP3 '/Perl.*one.*liner/' file1 file2 file3

Loop over args, printing each with line ending.  And same, shouting:

    pl -opl '' Perl one liner
    pl -opl '$_ = uc' Perl one liner

Count hits in magic statistics hash "%n(umber)":

    pl -n '++$n{$1} while /(Perl|one|liner)/g' file1 file2 file3