厳密な構文チェック

コマンドでチェック

perl -cw プログラムファイル

C:\Perl\src>perl -cw strict.pl
Name "main::num" used only once: possible typo at strict.pl line 3.
Name "main::nun" used only once: possible typo at strict.pl line 4.
strict.pl syntax OK

ソースでチェック

use warnings

C:\Perl\src>perl strict.pl
Name "main::num" used only once: possible typo at strict.pl line 3.
Name "main::nun" used only once: possible typo at strict.pl line 4.
Use of uninitialized value in print at strict.pl line 4.

use strict

C:\Perl\src>perl strict.pl
Global symbol "$num" requires explicit package name at strict.pl line 3.
Global symbol "$nun" requires explicit package name at strict.pl line 4.
Execution of strict.pl aborted due to compilation errors.

結果みて、なんとなくイメージがついた。