Perl - 正規表現によるテキスト処理 - 重複の回避、ダイヤモンド演算子、コマンドライン引数、リスト(ARGV)、コピーライト表示の追加、置換、バックアップ、書き戻し編集

初めてのPerl 第7版
原著: Learning Perl:
Making Easy Things Easy
and Hard Things Possible
楽天ブックス Yahoo!

開発環境

• macOS Mojave - Apple (OS)
• Emacs (Text Editor)
• Windows 10 Pro (OS)
• Strawberry Perl (WindowsのPerlの言語処理系)
• Visual Studio Code (Text Editor)
• Perl 5.28 (プログラミング言語)

初めてのPerl 第7版 (Randal L. Schwartz(著)、brian d foy(著)、Tom Phoenix(著)、近藤 嘉雪(翻訳)、嶋田 健志(翻訳)、オライリージャパン)の9章(正規表現によるテキスト処理)、9.6(練習問題)5の解答を求めてみる。

コード

#!/usr/bin/env perl
use strict;
use warnings;
use v5.28;

say '5.';

my %files;
for (@ARGV) {
    $files{$_} = 1;
}

while (<>) {
    if (/\A## Copyright/) {
        delete $files{$ARGV};
    }
}

@ARGV = keys %files;

$^I = ".bak";
while (<>) {
    if (/\A#!/) {
        $_ .= '## Copyright (C) 2020 by kamimura\n'
    }
    print;
}

入出力結果(Zsh、PowerShell、Terminal)

% ls dir5         
./  sample1.pl* sample3.pl* sample5.pl*
../  sample2.pl* sample4.pl*
% head dir5/* 
==> dir5/sample1.pl <==
#!/usr/bin/env perl
use strict;
use warnings;
use v5.28;

say '1.';

my $what = shift @ARGV;

while (<>) {

==> dir5/sample2.pl <==
#!/usr/bin/env perl
## Copyright ©️ 2020 by kamimura
use strict;
use warnings;
use v5.28;

say '2.';

my $filename = shift @ARGV;


==> dir5/sample3.pl <==
#!/usr/bin/env perl
use strict;
use warnings;
use v5.28;

say '3.';

my $filename = shift @ARGV;

open my $in_fh, '<', $filename or die $!;

==> dir5/sample4.pl <==
#!/usr/bin/env perl
## Copyright (C) 2020 by kamimura
use strict;
use warnings;
use v5.28;

say '4.';

$^I = '.bak';


==> dir5/sample5.pl <==
#!/usr/bin/env perl
use strict;
use warnings;
use v5.28;

say '5.';

my %files;
for (@ARGV) {
    $files{$_} = 1;
% ./sample5.pl dir5/*
5.
% ls dir5   
./  sample1.pl* sample2.pl* sample3.pl.bak* sample5.pl*
../  sample1.pl.bak* sample3.pl* sample4.pl* sample5.pl.bak*
% head dir5/*.pl
==> dir5/sample1.pl <==
#!/usr/bin/env perl
## Copyright (C) 2020 by kamimura\nuse strict;
use warnings;
use v5.28;

say '1.';

my $what = shift @ARGV;

while (<>) {

==> dir5/sample2.pl <==
#!/usr/bin/env perl
## Copyright ©️ 2020 by kamimura
use strict;
use warnings;
use v5.28;

say '2.';

my $filename = shift @ARGV;


==> dir5/sample3.pl <==
#!/usr/bin/env perl
## Copyright (C) 2020 by kamimura\nuse strict;
use warnings;
use v5.28;

say '3.';

my $filename = shift @ARGV;

open my $in_fh, '<', $filename or die $!;

==> dir5/sample4.pl <==
#!/usr/bin/env perl
## Copyright (C) 2020 by kamimura
use strict;
use warnings;
use v5.28;

say '4.';

$^I = '.bak';


==> dir5/sample5.pl <==
#!/usr/bin/env perl
## Copyright (C) 2020 by kamimura\nuse strict;
use warnings;
use v5.28;

say '5.';

my %files;
for (@ARGV) {
    $files{$_} = 1;
% head dir5/*.bak
==> dir5/sample1.pl.bak <==
#!/usr/bin/env perl
use strict;
use warnings;
use v5.28;

say '1.';

my $what = shift @ARGV;

while (<>) {

==> dir5/sample3.pl.bak <==
#!/usr/bin/env perl
use strict;
use warnings;
use v5.28;

say '3.';

my $filename = shift @ARGV;

open my $in_fh, '<', $filename or die $!;

==> dir5/sample5.pl.bak <==
#!/usr/bin/env perl
use strict;
use warnings;
use v5.28;

say '5.';

my %files;
for (@ARGV) {
    $files{$_} = 1;
%