PHP user registration Information validation regular expression _php tips

The following method of verifying username is that the username must consist of a letter with a number of dashes, let's take a look at the example below.

1. Check that the user name is in accordance with the provisions of "more than two letters, numbers, or underline", the code is as follows:

/** 
 * Check User name compliance * * 
 @param STRING $username user name to check 
 * @return TRUE or FALSE/ 
function Is_ Username ($username) 
{ 
$strlen = strlen ($username); 
if (!preg_match ("/^[a-za-z0-9_\x7f-\xff][a-za-z0-9_\x7f-\xff]+$/", 
$username))//Open source software: phpfensi.com 
{ return 
false; 
} ElseIf (< $strlen | | | $strlen < 2) 
{return 
false; 
} 
return true; 

Two-digit letters, numbers, or underscores : ^[a-za-z0-9_\x7f-\xff][a-za-z0-9_\x7f-\xff]+$.

Note: Here, the letters are a-z,a-z, and the ASCII characters from 127 to 255 (0X7F-0XFF)

2, Password:6-20 digits, composed of letters, numbers, code as follows:

function Ispwd ($value, $minLen =5, $maxLen =16) { 
$match = '/^[\\~!@#$%^&* ()-_=+|{} \[\],.? \/:;\ ' \d\w]{'. $minLen. ', '. $maxLen. '} $/'; 
$v = Trim ($value); 
if (Emptyempty ($v)) return 
false; 
Return Preg_match ($match, $v); 

3, email verification , the code is as follows:

function Isemail ($value, $match = '/^[\w\d]+[\wd-.] *@[w\d-.] +\. [\w\d] {2,10}$/i ')

{ 
$v = trim ($value); 
if (Emptyempty ($v)) return 
false; 
Return Preg_match ($match, $v); 
} 

This article for everyone to share the user registration information: User name, password and the regular expression of the mailbox verification, I hope you seriously learn this "PHP user registration information validation Regular expression", will be harvested.