#! perl -slw use strict; use Data::Dump qw[ pp ]; sub hgrep (&\%) { my( $code, $href ) = @_; map{ local @_; $code->( @_ = each %$href ) ? @_ : () } 1 .. keys %$href; } sub hmap (&\%) { my( $code, $href ) = @_; map{ local @_; $code->( @_ = each %$href ) } 1 .. keys %$href; } my %h = 'a'..'z'; print join ' ', hgrep{ $_[0] =~ /[a-m]/ } %h; print join ' ', hmap{ "$_[0] => $_[1]" } %h; my %orig = ( cat => 22, dog => 23, category => 66, catalyst => 77, cataclysm => 88, dogma => 89, dogstar => 92, ); my %h2 = hgrep{ $_[0] =~ /^cat/ } %orig; pp\%h2; __END__ C:\test>hfp e f a b m n c d k l g h i j w => x e => f a => b m => n s => t y => z u => v c => d k => l q => r g => h i => j o => p { cat => 22, cataclysm => 88, catalyst => 77, category => 66 }