string 从另一个字符串 -Perl 中提取所需的子字符串
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Extract the required substring from another string -Perl
提问by Amey
I want to extract a substring from a line in Perl. Let me explain giving an example:
我想从 Perl 的一行中提取一个子字符串。我举个例子来解释一下：
fhjgfghjk3456mm 735373653736
icasd 666666666666
111111111111
In the above lines, I only want to extract the 12 digit number. I tried using splitfunction:
在上面几行中，我只想提取 12 位数字。我尝试使用split功能：
my @cc = split(/[0-9]{12}/,$line);
print @cc;
But what it does is removes the matched part of the string and stores the residue in @cc. I want the part matching the pattern to be printed. How do I that?
但它所做的是删除字符串的匹配部分并将剩余部分存储在@cc. 我想要打印与图案匹配的部分。我怎么办？
采纳答案by PinkElephantsOnParade
The $1 built-in variable stores the last match from a regex. Also, if you perform a regex on a whole string, it will return the whole string. The best solution here is to put parentheses around your match then print $1.
$1 内置变量存储来自正则表达式的最后一个匹配项。此外，如果您对整个字符串执行正则表达式，它将返回整个字符串。这里最好的解决方案是在你的匹配项周围加上括号，然后打印 $1。
my $strn = "fhjgfghjk3456mm 735373653736\nicasd\n666666666666 111111111111";
$strn =~ m/([0-9]{12})/;
print ;
This makes our regex match JUST the twelve digit number and then we return that match with $1.
这使得我们的正则表达式只匹配 12 位数字，然后我们用 $1 返回匹配。
回答by simbabque
You can do it with regular expressions:
你可以用正则表达式做到这一点：
#!/usr/bin/perl
my $string = 'fhjgfghjk3456mm 735373653736 icasd 666666666666 111111111111';
while ($string =~ m/\b(\d{12})\b/g) {
say ;
}
Test the regex here: http://rubular.com/r/Puupx0zR9w
在这里测试正则表达式：http: //rubular.com/r/Puupx0zR9w
use YAPE::Regex::Explain;
print YAPE::Regex::Explain->new(qr/\b(\d+)\b/)->explain();
The regular expression:
(?-imsx:\b(\d+)\b)
matches as follows:
NODE EXPLANATION
----------------------------------------------------------------------
(?-imsx: group, but do not capture (case-sensitive)
(with ^ and $ matching normally) (with . not
matching \n) (matching whitespace and #
normally):
----------------------------------------------------------------------
\b the boundary between a word char (\w) and
something that is not a word char
----------------------------------------------------------------------
( group and capture to :
----------------------------------------------------------------------
\d+ digits (0-9) (1 or more times (matching
the most amount possible))
----------------------------------------------------------------------
) end of
----------------------------------------------------------------------
\b the boundary between a word char (\w) and
something that is not a word char
----------------------------------------------------------------------
) end of grouping
----------------------------------------------------------------------
回答by Rawkode
#!/bin/perl
my $var = 'fhjgfghjk3456mm 735373653736 icasd 666666666666 111111111111';
if($var =~ m/(\d{12})/) {
print "Twelve digits: .";
}
回答by cdtits
#!/usr/bin/env perl
undef $/;
$text = <DATA>;
@res = $text =~ /\b\d{12}\b/g;
print "@res\n";
__DATA__
fhjgfghjk3456mm 735373653736
icasd 666666666666
111111111111
