2009/05/24
Perlで書く 2009.05.24 Vol.234
===================================================================== Perlで書く 2009.05.24 Vol.234 [WAZA]詳細な警告文の出力 http://www2u.biglobe.ne.jp/~MAS/perl/ ===================================================================== ●詳細な警告文の出力 diagnosticsプラグマを使うとwarningsプラグマよりも詳しい説明文で警告を 表示するようになります。 --------------------------------------------------------------------- # diagnosticsプラグマを使ったスクリプト use strict; use diagnostics; my $value; print $value; --------------------------------------------------------------------- # diagnosticsプラグマを使ったスクリプトの警告文 Use of uninitialized value in print at diagnostics.pl line 6 (#1) (W uninitialized) An undefined value was used as if it were already defined. It was interpreted as a "" or a 0, but maybe it was a mistake. To suppress this warning assign a defined value to your variables. To help you figure out what was undefined, perl tells you what operation you used the undefined value in. Note, however, that perl optimizes your program and the operation displayed in the warning may not necessarily appear literally in your program. For example, "that $foo" is usually optimized into "that " . $foo, and the warning will refer to the concatenation (.) operator, even though there is no . in your program. --------------------------------------------------------------------- # warningsプラグマを使ったスクリプト use strict; use warnings; my $value; print $value; --------------------------------------------------------------------- # warningsプラグマを使ったスクリプトの警告文 Use of uninitialized value in print at warnings.pl line 6. --------------------------------------------------------------------- ●関連項目 ・warn関数 http://www2u.biglobe.ne.jp/~MAS/perl/ref/warn.html ・CGIのデバッグ http://www2u.biglobe.ne.jp/~MAS/perl/waza/cgidebug.html ・トレース表示 http://www2u.biglobe.ne.jp/~MAS/perl/waza/trace.html ===================================================================== ■雑記 特にありません。 ===================================================================== Perlで書く(マガジンID：0000109251) 配信数：840 発行者：MAS 本メールマガジンに関するご意見・お問い合わせは t-masuda@mvd.biglobe.ne.jp までお寄せ下さい。 解除 http://www2u.biglobe.ne.jp/~MAS/perl/magazine.html 検索 http://www2u.biglobe.ne.jp/~MAS/perl/search/index.html バックナンバー http://archive.mag2.com/0000109251/index.html RSS http://archive.mag2.com/0000109251/rss10.xml 本メールマガジンは「まぐまぐ」 http://www.mag2.com/ を利用して発行 しています。 =====================================================================
