如何在Perl中查找和替换正则表达式

Question

我有一个文本，想要将所有\\w\\( ，例如myword(替换为一个空格，所以应该是myword ( 。如何用s/// ？或有另一种方法来做到这一点）。 ？

Answer 1

Try this

$s = "myword( word2(";
$s =~s/(\w+)(\()/$1 $2/g;
print $s;

As from @ikegami command. My above regex \\w+ will backtrack this is needless. And no need to group the ( , because known one. So i changed my regex accordingly,

New RegEx

$s =~s/(\w)\(/$1 (/g;

Answer 2

Here is a way:

my $str = "myword(";
$str =~ s/(\w+)(\()/$1 $2/;
print $str, "\n";

Output:

myword (

Answer 3

Use look ahead:

$ perl -pe 's/(\w)(?=\()/$1 /' <<< 'word('
word (

Or look ahead together with look behind:

$ perl -pe 's/(?<=\w)(?=\()/ /' <<< 'word('
word (

Answer 4

Another way will be to use \\K ie forget what you matched before:

#!/usr/bin/perl
use strict;
use warnings;

my $string = q{myword( myword2(};
$string=~s/\w\K\(/ (/g;
print $string,"\n";

Answer 5

s/\w\K\(/ (/g   # 5.10+

or

s/(\w)\(/$1 (/g

or

s/(?<=\w)\(/ (/g

The first is much faster than the other two, but all are faster than the other correct solutions provided. (Not sure which is the fastest of the second and third.)