以下Perl脚本和正则表达式从给定文本文件中提取所有电子邮件地址。

示例文本：

This perl script extracts all email addresses
from an given text file. This email address
is valid: web@email.net and this email address
is not valid web@email. Same as what_ever@public.com 
is a valid email address and address test@test. is 
not valid !

使用Perl通过正则表达式提取电子邮件地址：

#!/usr/bin/perl
use strict;
my $email_count;
while (my $line = <>) { #read from file or STDIN
  foreach my $email (split /\s+/, $line) {
     if ( $email =~ /^[-\w.]+@([a-z0-9][a-z-0-9]+\.)+[a-z]{2,4}$/i ) {
 		print $email . "\n";
		$email_count++;

  }
}
}
print "Emails Extracted: $email_count\n";

执行：

$ ./extract_email.pl emails.txt
web@email.net
what_ever@public.com
emails Extracted: 2