Perl - 中級者の基礎知識 - リスト演算子、grepによるフィルタリング、ファイルサイズ、mapによる変換、文字列

続・初めてのPerl 改訂第2版
楽天ブックス Yahoo!
原著: Intermediate Perl:
Beyond The Basics of Learning Perl

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 5.30 (プログラミング言語)

続・初めてのPerl 改訂第2版 (Randal L. Schwartz(著)、brian d foy(著)、Tom Phoenix(著)、伊藤 直也(監修)、長尾 高弘(翻訳)、オライリージャパン)の3章(中級者の基礎知識)、3.5(練習問題)1の解答を求めてみる。

コード

#!/usr/bin/env perl
use strict;
use warnings;
use v5.30;

say '1.';

print map { " " x 4 . $_ . "\n"} grep { -s $_ < 1000} @ARGV;

入出力結果(Zsh、PowerShell、Terminal)

% ./sample1.pl 
1.
% ./sample1.pl /etc/*
1.
    /etc/afpovertcp.cfg
    /etc/afpovertcp.cfg~orig
    /etc/apache2
    /etc/asl
    /etc/auto_home
    /etc/auto_master
    /etc/auto_master~orig
    /etc/bashrc
    /etc/bashrc~previous
    /etc/bootpd.plist
    /etc/com.apple.screensharing.agent.launchd
    /etc/csh.cshrc
    /etc/csh.cshrc~orig
    /etc/csh.login
    /etc/csh.login~orig
    /etc/csh.logout
    /etc/csh.logout~orig
    /etc/cups
    /etc/defaults
    /etc/emond.d
    /etc/find.codes
    /etc/find.codes~orig
    /etc/fstab.hd
    /etc/fstab.hd~previous
    /etc/ftpusers
    /etc/ftpusers~orig
    /etc/hosts
    /etc/hosts.equiv
    /etc/hosts~orig
    /etc/kern_loader.conf
    /etc/kern_loader.conf~previous
    /etc/localtime
    /etc/locate.rc
    /etc/mail.rc
    /etc/mail.rc~orig
    /etc/manpaths
    /etc/manpaths.d
    /etc/nanorc
    /etc/networks
    /etc/networks~orig
    /etc/newsyslog.d
    /etc/nfs.conf
    /etc/nfs.conf~orig
    /etc/notify.conf
    /etc/ntp.conf
    /etc/ntp_opendirectory.conf
    /etc/openldap
    /etc/pam.d
    /etc/paths
    /etc/paths.d
    /etc/paths~orig
    /etc/periodic
    /etc/pf.anchors
    /etc/php-fpm.d
    /etc/ppp
    /etc/profile
    /etc/profile~orig
    /etc/racoon
    /etc/resolv.conf
    /etc/rmtab
    /etc/rtadvd.conf
    /etc/rtadvd.conf~previous
    /etc/security
    /etc/shells
    /etc/shells~orig
    /etc/snmp
    /etc/ssh
    /etc/ssl
    /etc/sudo_lecture
    /etc/sudoers.d
    /etc/syslog.conf
    /etc/syslog.conf~previous
    /etc/thnuclnt
    /etc/wfs
    /etc/xtab
    /etc/zprofile
    /etc/zshrc_Apple_Terminal
% perl -w -e 'print map{"    $_\n"}grep{-s $_ <1000}@ARGV' /etc/*
    /etc/afpovertcp.cfg
    /etc/afpovertcp.cfg~orig
    /etc/apache2
    /etc/asl
    /etc/auto_home
    /etc/auto_master
    /etc/auto_master~orig
    /etc/bashrc
    /etc/bashrc~previous
    /etc/bootpd.plist
    /etc/com.apple.screensharing.agent.launchd
    /etc/csh.cshrc
    /etc/csh.cshrc~orig
    /etc/csh.login
    /etc/csh.login~orig
    /etc/csh.logout
    /etc/csh.logout~orig
    /etc/cups
    /etc/defaults
    /etc/emond.d
    /etc/find.codes
    /etc/find.codes~orig
    /etc/fstab.hd
    /etc/fstab.hd~previous
    /etc/ftpusers
    /etc/ftpusers~orig
    /etc/hosts
    /etc/hosts.equiv
    /etc/hosts~orig
    /etc/kern_loader.conf
    /etc/kern_loader.conf~previous
    /etc/localtime
    /etc/locate.rc
    /etc/mail.rc
    /etc/mail.rc~orig
    /etc/manpaths
    /etc/manpaths.d
    /etc/nanorc
    /etc/networks
    /etc/networks~orig
    /etc/newsyslog.d
    /etc/nfs.conf
    /etc/nfs.conf~orig
    /etc/notify.conf
    /etc/ntp.conf
    /etc/ntp_opendirectory.conf
    /etc/openldap
    /etc/pam.d
    /etc/paths
    /etc/paths.d
    /etc/paths~orig
    /etc/periodic
    /etc/pf.anchors
    /etc/php-fpm.d
    /etc/ppp
    /etc/profile
    /etc/profile~orig
    /etc/racoon
    /etc/resolv.conf
    /etc/rmtab
    /etc/rtadvd.conf
    /etc/rtadvd.conf~previous
    /etc/security
    /etc/shells
    /etc/shells~orig
    /etc/snmp
    /etc/ssh
    /etc/ssl
    /etc/sudo_lecture
    /etc/sudoers.d
    /etc/syslog.conf
    /etc/syslog.conf~previous
    /etc/thnuclnt
    /etc/wfs
    /etc/xtab
    /etc/zprofile
    /etc/zshrc_Apple_Terminal
%