sub print_message { print "\n", "-" x 50, "\n$_[0]\n", "-" x 50, "\n" }
复制代码
输出:
--------------------------------------------------
Before I do anything
--------------------------------------------------
Size is 24
--------------------------------------------------
After I assign a string
--------------------------------------------------
Size is 56
--------------------------------------------------
After I use it as a number
--------------------------------------------------
Size is 64
因为好几个地方都用到print_message,每次复制粘贴比较麻烦,就把它作成一个小的模块
#Print.pm
package Print;
require Exporter;
our @ISA = qw(Exporter);
our @EXPORT = qw(print_message);
our @EXPORT_OK = qw();
our $VERSION = 1.00;
sub print_message {
print STDERR "\n", "-" x 50,
"\n$_[0]\n", "-" x 50, "\n";
}
1
#size.plx
#!/usr/bin/perl
use strict;
use warnings;
use Devel::Size qw/size/;
use Print;
my $n;
print_message("Before I do anything");
print "Size is ", size(\$n);
print_message("After I do something");
$n = '1';
print "Size is ", size(\$n);
print_message("After I do anything");
my $m = $n + 1;
print "Size is ", size(\$n);
复制代码
输出变成这样了:
--------------------------------------------------
Before I do anything
--------------------------------------------------
--------------------------------------------------
After I do something
--------------------------------------------------
--------------------------------------------------
After I do anything
--------------------------------------------------
Size is 24Size is 56Size is 64