Question

#! /usr/bin/perl

$str = "ab_cde,efg_gh,drg_fgt,main_xx,sum(abc),avg(def)";

或

$str = "ab_cde,bc_bn,gy_ihf,efg_gh,drg_fgt,main_xx,sum(abc),avg(def‌)";

伙计们，main_xx之前的字符串是动态的，意味着可以有更多使用此格式的元素，例如xx_xx或xxx_xx或xx_xxx或xxx_xxxx或它可以是“下划线”之前和之后的多个字符。因此，在main_xx之前，可以使用上述格式的许多元素。我想匹配字符串UP TO main_xx because even fetching dynamically, this "main_xx" will be the last element and want to ignore elements after main_xx`。请帮助创建一个正则表达式。

Answer 1

#!/usr/bin/perl -w
use strict;

my $str = "ab_cde,efg_gh,drg_fgt,main_xx,sum(abc),avg(def)";
(my $result) = ($str =~ m/(.*main_xx)/);
print $result;

输出将是main_xx之前的所有内容（给定xx只是由x组成的字符串）。

Answer 2

试试这个

my $str = "ab_cde,efg_gh,drg_fgt,main_xx,sum(abc),avg(def)";
my ($match)= $str =~m/(.+main_xx)/;
print $match;

需要正则表达式的下列表达式？

2 个答案: