#! /usr/bin/perl use strict; my $limit = $ARGV[0] || 10; my $index = 0; my $result = "I am glad."; $result = ( "I am", "you are" )[ $index = not $index ] . " glad " . $result foreach ( 1..$limit ); print $result, "\n"; #### c:/Data $ perl fn.pl 20 I am glad you are glad I am glad you are glad I am glad you are glad I am glad you are glad I am glad you are glad I am glad you are glad I am glad you are glad I am glad you are glad I am glad you are glad I am glad you are glad I am glad. #### #! /usr/bin/perl use strict; my $limit = $ARGV[0] || 10; my $result = "jeg er glad."; while( my $head = &swap ) { $result = $head. " er glad " . $result; } print $result, "\n"; BEGIN { my @oss = qw( jeg du ); my ( $index, $count ); sub swap{ ( $limit > $count++ ) ? return $oss[ $index = not $index ] : return; } } #### $result = $head. " er glad " . $result while( my $head = &swap );