Perl语言入门-第八章-以正则表达式进行匹配-习题

1. 题目

   

   

2. 代码与输出

 1 #-----------------------------------------------------------#
 2 # Source: Learning Perl, chapter8,exercise-1
 3 # Date:   2012-01-18
 4 # Author: xiaodongrush
 5 #-----------------------------------------------------------#
 6 use 5.010;
 7 while(<>) {
 8   chomp;
 9   if($_ =~ m|match|) {
10     say "<$`><$&><$'>";
11   }
12 }
13 #-----------------------------------------------------------#
14 # 1. /match/ 是对 m/match/的简写
15 #    m/match/,m|match|,m<match>,m{match}这些都是等价的
16 # 2. =~可以匹配指定的变量 
17 #-----------------------------------------------------------#

 1 #-----------------------------------------------------------#
 2 # Source: Learning Perl, chapter8,exercise-2
 3 # Date:   2012-01-18
 4 # Author: xiaodongrush
 5 #-----------------------------------------------------------#
 6 use 5.010;
 7 while(<>) {
 8   chomp;
 9   if($_ =~ m|\b\w*a\b|) {
10     say "<$`><$&><$'>";
11   }
12 }
13 #-----------------------------------------------------------#
14 # 1. \w等价于[A-Za-z0-9_]，即字母、数字和下划线
15 # 2. \b是表示单词开始或结束位置
16 # 3. 不能匹配到Mrs._Wilma_Flintsone，因为下划线属于\w，为\b
17 #    匹配“非\w”的位置
18 #-----------------------------------------------------------#

 1 #-----------------------------------------------------------#
 2 # Source: Learning Perl, chapter8,exercise-3
 3 # Date:   2012-01-18
 4 # Author: xiaodongrush
 5 #-----------------------------------------------------------#
 6 use 5.010;
 7 while(<>) {
 8   chomp;
 9   if($_ =~ m|\b(\w*a)\b|) {
10     say "<$`><$&><$'>";
11     say '$1 contains ' . "\'$1\'";
12   }
13 }
14 #-----------------------------------------------------------#

 1 #-----------------------------------------------------------#
 2 # Source: Learning Perl, chapter8,exercise-4
 3 # Date:   2012-01-18
 4 # Author: xiaodongrush
 5 #-----------------------------------------------------------#
 6 use 5.010;
 7 while(<>) {
 8   chomp;
 9   if($_ =~ m|\b(?<word>\w*a)\b|) {
10     say "<$`><$&><$'>";
11     say 'word contains ' . "\'$+{word}\'";
12   }
13 }
14 #-----------------------------------------------------------#
15 # 1. 定义命名捕获 (?<命名>待捕获模式串)
16 #    使用命名捕获 $+{命名}
17 #-----------------------------------------------------------#

 1 #-----------------------------------------------------------#
 2 # Source: Learning Perl, chapter8,exercise-5
 3 # Date:   2012-01-18
 4 # Author: xiaodongrush
 5 #-----------------------------------------------------------#
 6 use 5.010;
 7 while(<>) {
 8   chomp;
 9   if($_ =~ m|\b\w*a\b(?<word>.{0,5})|) {
10     say "<$`><$&><$'>";
11     say '$1 contains ' . "\'$1\'";
12     say 'word contains ' . "\'$+{word}\'";
13   }
14 }
15 #-----------------------------------------------------------#
16 # 1. 通用量词，{0,5} 0次到5次，{0,}0次或者以上
17 #-----------------------------------------------------------#

 1 #-----------------------------------------------------------#
 2 # Source: Learning Perl, chapter8,exercise-6
 3 # Date:   2012-01-18
 4 # Author: xiaodongrush
 5 #-----------------------------------------------------------#
 6 use 5.010;
 7 while(<>) {
 8   chomp;
 9   if($_ =~ m|\s$|) {
10     say "|$`|$&|$'|";
11     say "|$_|";
12   }
13 }
14 #-----------------------------------------------------------#
15 # 如果匹配成功，那么$&将是字符串的最后一个空白，而$'是空串
16 # $`是除了最后一个空白的前面所有字符
17 #-----------------------------------------------------------#

3. 文件

    /Files/pangxiaodong/LearningPerl/ch8-answer.rar