Home Backend Development PHP Tutorial Detailed explanation of functions that come with PHP to verify whether email, URL, and IP are legal

Detailed explanation of functions that come with PHP to verify whether email, URL, and IP are legal

May 31, 2018 am 09:22 AM
ip php url Mail verify

In the past, I used PHP to verify whether the email, URL, and IP were legal by writing regular rules myself. However, sometimes I was confused and might write a regular rule that was not completely correct, causing verification errors. Today I discovered that PHP itself automatically With functions to verify whether the email, URL, and IP are legal

The filter_var function is mainly used.

Syntax

filter_var(variable, filter, options)

Parameter description

variable Required. Specifies the variables to filter.

filter Optional. Specifies the ID of the filter to use.

options Specifies an array containing flags/options. Check the possible flags and options for each filter.

PHP Filters

HTML escape characters ‘”<>& and characters with ASCII values ​​less than 32.Delete all characters , except numbers and -Remove all characters except numbers, - and.,eE.Apply addslashes().
ID Name Description
FILTER_CALLBACK Call user-defined function to filter data.
FILTER_SANITIZE_STRING Remove tags, remove or encode special characters.
FILTER_SANITIZE_STRIPPED "string" Alias ​​for the filter.
FILTER_SANITIZE_ENCODED URL-encode string, remove or encode special characters.
##FILTER_SANITIZE_SPECIAL_CHARS
FILTER_SANITIZE_EMAIL Remove all characters except letters, numbers and !#$%&'* -/=?^_`{| }~@.[]
FILTER_SANITIZE_URL Remove all characters except letters, numbers and $-_. !*'(), {}|\\^~[]`<>#%”;/?:@&=
#FILTER_SANITIZE_NUMBER_INT
FILTER_SANITIZE_NUMBER_FLOAT
FILTER_SANITIZE_MAGIC_QUOTES
FILTER_UNSAFE_RAW Does not do any filtering, stripping or encoding of special characters.
FILTER_VALIDATE_INT Validates values ​​as integers in the specified range.
FILTER_VALIDATE_BOOLEAN If it is "1", "true", "on" and "yes", then return true, if it is " 0″, “false”, “off”, “no” and “”, then false is returned. Otherwise NULL is returned.
FILTER_VALIDATE_FLOAT Validate the value as a floating point number.
FILTER_VALIDATE_REGEXP Validates values ​​based on regexp, a Perl-compatible regular expression.
FILTER_VALIDATE_URL Validate the value as a URL.
FILTER_VALIDATE_EMAIL Validate the value as an e-mail.
FILTER_VALIDATE_IP Validate the value as an IP address.


Example #1 A filter_var() example

<?php
var_dump(filter_var(&#39;bob@example.com&#39;, FILTER_VALIDATE_EMAIL));
var_dump(filter_var(&#39;http://example.com&#39;, FILTER_VALIDATE_URL, FILTER_FLAG_PATH_REQUIRED));
?>
Copy after login

The above routine will output:

string(15) "bob@example.com"
bool(false)
Copy after login

The above is the content of this article All content, I hope it will be helpful to everyone's study.

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