Perl - 正規表現によるマッチ(マッチグループ、キャプチャ変数)

初めてのPerl 第6版
Randal L. Schwartz,
Tom Phoenix, brian d foy 共著
近藤 嘉雪 翻訳

開発環境

• OS X Lion - Apple(OS)
• TextWrangler(Text Editor) (BBEditの機能制限無料版、light版)
• Script言語:Perl

『初めてのPerl 第6版』(Randal L. Schwartz, Tom Phoenix, brian d foy 共著、近藤 嘉雪 訳、オライリー・ジャパン、2012年、ISBN978-4-87311-567-2) の8章(正規表現によるマッチ)、8.10(練習問題)3を解いてみる。

その他参考書籍

• プログラミングPerl〈VOLUME1〉
• プログラミングPerl〈VOLUME2〉
• Perlクックブック〈VOLUME1〉
• Perlクックブック〈VOLUME2〉

3.

コード(TextWrangler)

sample.pl

#!/usr/bin/env perl
use strict;
use warnings;
use utf8;
use 5.016;
binmode STDIN, ':utf8';
binmode STDOUT, ':utf8';

while(<>){
  chomp;
  if(/\b(\w*a)\b/){
    print "Matched: |$`|<$&>$'|\n";
    print "  \$1 contains '$1'\n";
  } else {
    print "No match: |$_|\n";
  }
}

入出力結果(Terminal)

$ ./sample.pl test.txt
No match: |A|
Matched: ||<a>|
  $1 contains 'a'
Matched: ||<kamimura>'s blog|
  $1 contains 'kamimura'
Matched: |http://|<sitekamimura>.blogspot.com|
  $1 contains 'sitekamimura'
No match: |KMI|
Matched: |http://www.|<mkamimura>.com   |
  $1 contains 'mkamimura'
No match: |Fred|
No match: |FRED|
No match: |fred|
No match: |frederick|
No match: |Alfred|
No match: |fred flintstone|
No match: |Mr. Slate     |
No match: |Mississippi|
No match: |Bamm-Bamm    |
Matched: ||<wilama>|
  $1 contains 'wilama'
No match: |barney|
Matched: ||<wilma> and fred|
  $1 contains 'wilma'
Matched: |fred and |<wilma>|
  $1 contains 'wilma'
Matched: ||<Wilma> and Fred      |
  $1 contains 'Wilma'
Matched: |Fred and |<Wilma>|
  $1 contains 'Wilma'
Matched: ||<wilma>&fred|
  $1 contains 'wilma'
Matched: |Mrs. |<Wilma> Flintstone   |
  $1 contains 'Wilma'
Matched: |I saw |<Wilma> yesterday|
  $1 contains 'Wilma'
Matched: |I, |<Wilma>!|
  $1 contains 'Wilma'
No match: |Z|
Matched: ||<llama>|
  $1 contains 'llama'
$ cat test.txt
A
a
kamimura's blog
http://sitekamimura.blogspot.com
KMI
http://www.mkamimura.com   
Fred
FRED
fred
frederick
Alfred
fred flintstone
Mr. Slate     
Mississippi
Bamm-Bamm    
wilama
barney
wilma and fred
fred and wilma
Wilma and Fred      
Fred and Wilma
wilma&fred
Mrs. Wilma Flintstone   
I saw Wilma yesterday
I, Wilma!
Z
llama
$

ちなみにJavaScriptの場合。

コード(TextWrangler)

var result = "";
var str = "A\na\nkamimura's blog\nhttp://sitekamimura.blogspot.com\nKMI\nhttp://www.mkamimura.com   \nFred\nFRED\nfred\nfrederick\nAlfred\nfred flintstone\nMr. Slate     \nMississippi\nBamm-Bamm    \nwilama\nbarney\nwilma and fred\nfred and wilma\nWilma and Fred      \nFred and Wilma\nwilma&fred\nMrs. Wilma Flintstone   \nI saw Wilma yesterday\nI, Wilma!\nZ\nllama\n";
var lines = str.split("\n");
for(var i = 0; i < lines.length; i++){
  if(lines[i].match(/\b(\w*a)\b/)){
    result += lines[i] + "\n" +
      "    " + RegExp.$1 + "\n";
  }
}
$('#pre0').text(result);

pythonの場合。

sample.py

コード(TextWrangler)

#!/usr/bin/env python3.3
#-*- coding:utf-8 -*-

import sys, re

for line in open(sys.argv[1]):
    a = re.search(r"\b\w*a\b", line)
    if a:
        print(line, end="")
        print("    " + a.group())

入出力結果(Terminal)

$ ./sample.py test.txt
a
    a
kamimura's blog
    kamimura
http://sitekamimura.blogspot.com
    sitekamimura
http://www.mkamimura.com   
    mkamimura
wilama
    wilama
wilma and fred
    wilma
fred and wilma
    wilma
Wilma and Fred      
    Wilma
Fred and Wilma
    Wilma
wilma&fred
    wilma
Mrs. Wilma Flintstone   
    Wilma
I saw Wilma yesterday
    Wilma
I, Wilma!
    Wilma
llama
    llama
$