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  • perl + 匹配前导模式一次或者多次

    Vsftp:/data01/mysqllog/binlog# cat a2.pl
    $_="aaaa@[2]sasas";
    if ($_ =~/.*?(@[[0-9]+]).*/){print "$id is $1
    "};
    
    Vsftp:/data01/mysqllog/binlog# perl a2.pl
    $id is @[2]
    
    
    
    Vsftp:/data01/mysqllog/binlog# cat a2.pl
    $_="aaaa@[23]sasas";
    if ($_ =~/.*?(@[[0-9]+]).*/){print "$id is $1
    "};
    
    Vsftp:/data01/mysqllog/binlog# perl a2.pl
    $id is @[23]
    
    d+ 匹配多个数字字符串,和 [0-9]+ 语法一样 
    +匹配前导模式一次或多次
    
    
    [oracle@oadb test]$ cat a3.pl 
    $_="aaaa@[3]sasas";
    if ($_ =~/.*?(@[[0-9]{1,3}]).*/){print "$id is $1
    "};
    
    [oracle@oadb test]$ perl a3.pl 
    $id is @[3]
    
    
    [oracle@oadb test]$ cat a3.pl 
    $_="aaaa@[30]sasas";
    if ($_ =~/.*?(@[[0-9]{1,3}]).*/){print "$id is $1
    "};
    [oracle@oadb test]$ perl a3.pl 
    $id is @[30]
    
    
    [oracle@oadb test]$ cat a3.pl 
    $_="aaaa@[301]sasas";
    if ($_ =~/.*?(@[[0-9]{1,3}]).*/){print "$id is $1
    "};
    
    [oracle@oadb test]$ perl a3.pl 
    $id is @[301]
    
    
    [oracle@oadb test]$ cat a3.pl 
    $_="aaaa@[3012]sasas";
    if ($_ =~/.*?(@[[0-9]{1,3}]).*/){print "$id is $1
    "};
    [oracle@oadb test]$ perl a3.pl 
    [oracle@oadb test]$ 
    
    [0-9]{1,3} 匹配1到3次
    
    {m} 匹配刚好是 m 个 的指定字符串 
    
    {m,n} 匹配在 m个 以上 n个 以下 的指定字符串 
    
    {m,} 匹配 m个 以上 的指定字符串 


    
       
    
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  • 原文地址:https://www.cnblogs.com/zhaoyangjian724/p/6198929.html
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