Perl 特殊字符

^和$只能定位在字串的开始和结束处，它们并不匹配嵌入的换行符，这种情况等同于A和Z，否则不仅仅匹配字串的开始和结束，也匹配刚好处在嵌入换行符前后的一个位置


v-lhb-db01:/root/perl# cat t1.pl 
$_='a123a';

if ($_ =~ /Ad+z/){print "111n"};

v-lhb-db01:/root/perl# perl t1.pl 
v-lhb-db01:/root/perl# 


v-lhb-db01:/root/perl# cat t1.pl 
$_='123a';

if ($_ =~ /Ad+z/){print "111n"};
v-lhb-db01:/root/perl# perl t1.pl 
v-lhb-db01:/root/perl# 


v-lhb-db01:/root/perl# cat t1.pl 
$_='123';

if ($_ =~ /Ad+z/){print "111n"};
v-lhb-db01:/root/perl# perl t1.pl 
11