调和的松树林

#!/usr/bin/perl

$tmp=”20080418a”;

$tmp2=`date +\%Y\%m\%d`;
print “$tmp2″;
print “$tmp2″;
print “$tmp\n”;

20080418
20080418
20080418a
此时$tmp2为 20080418（包含回车）

=================

#!/usr/bin/perl

$tmp=”20080418a”;

$tmp2=system(”date +\%Y\%m\%d”);
print “$tmp2″;
print “$tmp2″;
print “$tmp\n”;

20080418
0020080418a
此时$tmp2为0 20080418为date +\%Y\%m\%d显示