プログラミング学習の記録 573.2 『初めてのPerl 第5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、2009年、ISBN978-4-87311-427-9)の7章(正規表現によるマッチ)の練習問題2

開発環境

• Mac OS X Snow Leopard (OS)
• TextWrangler(Text Editor) (いずれはBBEditを入手したい！)
• Script言語:Perl

『初めてのPerl 第5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、2009年、ISBN978-4-87311-427-9) の7章(正規表現によるマッチ), 7.4(練習問題)、2を解いてみる。

 

2.

やり方の1つ。(「やり方は何通りもある」(TIMTOWTDI(There Is More Than One Way To Do It.)))

コード(TextWrangler)

#!/usr/bin/perl
use strict;
use warnings;

while(<>){
  # 文字クラスを使用
  if(/[fF]red/){
    print "Matched: $_";
    }
}

入出力結果(Ternimal)

$ ./my_program Fred Matched: Fred frederick Matched: frederick Alfred Matched: Alfred

前問と違い、frederic, Alfredに加えてFredもマッチする。

次は"fred flinstone"と彼の友人の名前が入っている数行の小さなテキストファイルをプログラムに入力として与える。何行目でマッチしているか分かるように上記のコードを少し修正。

コード(TextWrangler)

#!/usr/bin/perl
use strict;
use warnings;

my $line=0;
while(<>){
  $line++;
  if(/[fF]red/){
    print "line $line: $_";
    }
}

入出力結果(Terminal)

$ ./my_program sample_text line 2: for fred and barney in lowercase, as we usually do. some lines line 3: mention a name like fred more than once so that you can search line 12: one evening, fred and barney were getting ready to go bowling. line 16: betty agreed. "barney and fred never think about us. we should line 23: so wilma found fred and told him, "hey, fred, you've been going line 27: "but wilma," said fred, "barney and i need to go tonight. this is line 31: that wasn't good enough for wilma. "fred flintstone, if you think line 39: discussion with betty. "i can't say no to you betty. but fred line 48: "well, this is why fred and i have been practicing all week. but line 49: you can't tell wilma what's going on, because fred made me line 61: you and fred can sneak over there." line 63: "i'll call fred and tell him our plan." line 67: fred had come up with a plan of his own. with his bowling ball in line 73: "nothing, nothing, dear," said fred, hurriedly hiding the bowling line 79: "no problem. i've caught it now," lied fred. "i'll just take it line 85: "uhm, black?" fred responded, holding the bowling ball behind his line 94: "fred flintstone, you let me see that mouse this minute!" cried line 97: the telephone rang. "you get that, wilma," said fred. "i'll be line 105: mister fred flintstone. is mister fred flintstone available to line 108: at that moment, fred rushed back into the house, having left the line 109: bowling ball in the car. "it's for you, fred," said wilma. line 112: "hello," fred said into the phone, not understanding. line 114: "heya, fred," said barney. "betty and i have figured out what to line 118: "yes, yes," said fred. wilma stood by, curious about this line 125: wilma was getting more curious. fred said, "well, that mineral, i line 128: "but fred," said barney, "it's a bowling ball, not a mineral." line 132: "fred, where do you keep your bowling ball? is it in the garage?" line 136: wilma interrupted him. "fred, give me the phone. i'll take care line 139: she pulled the phone away from fred in time to hear barney say,

前問と同じように以下からファイルのsample_textを入力として与えたけど、文章中に「Fred」が無く前問の入出力結果と同じに。。

ファイルの用意が必要な場合はO'Reilly Japan - 初めてのPerl 第5版の関連ファイルのプログラム例に含まれているものを使用しています。