PHP generated short URL method summary _php tips

The normal URL with the parameters of the kind may be very long, in particular, we are printed on paper products such as corporate brochure to print a long URL is very ugly, and few people will be to remember this site, although now can be used to scan two-dimensional code to open a long web site. But people can use short URLs to achieve beautiful links, especially with word-limiting applications such as microblogs.

The principle of the short URL is that there is a data table will be the configuration file will be a short URL and the actual URL for the corresponding, when the request for a short URL, the program to jump to the corresponding actual URL up, so as to achieve access to the Web site.

Scheme 1:php+mysql to realize the generation and reading of short URLs

The regular program we will generate a good short URL and the original URL to a data table, and then for reading use. Let's take a look at how to generate a unique short URL.

Generate short URL 
function code62 ($x) { 
  $show = '; 
  while ($x >0) { 
    $s = $x%; 
    if ($s >35) { 
      $s =chr ($s +61); 
    } ElseIf ($s >9&& $s <=35) { 
      $s =chr ($s +55); 
    } 
    $show. = $s; 
    $x =floor ($x/62); 
  return $show; 
} 
function Shorturl ($url) { 
  $url =crc32 ($url); 
  $result =sprintf ("%u", $url); 
  Return code62 ($result); 
echo shorturl (' http://www.jb51.net/'); 
1eeiv2 

Using the above PHP code can generate a unique 6-bit short URL, and then we will generate a short URL with the original URL to write to the MySQL table, insert the code of the database here I do not write, this is the basis of PHP.
Next, we have a link.php to receive the read URL and implement a real jump.

Include_once (' connect.php '); Connection database 
$url = $_get[' url ']; 
if (Isset ($url) &&!empty ($url)) { 
  $sql = "Select URL from shorturl where codeid= ' $url '"; 
  $query = mysql_query ($sql); 
  if ($row =mysql_fetch_array ($query)) { 
    $real _url = $row [' url ']; 
    Header (' Location: '. $real _url); 
  else{ 
    header (' http/1.0 404 Not Found '); 
    Echo ' Unknown link. '} 
} else{ 
  header (' http/1.0 404 Not Found '); 
  Echo ' Unknown link. '; 
} 

Code, if you get a short URL corresponding to the real URL, will use header to jump to the real page, otherwise return 404 code. This allows us to use such as: http://yourdomain/link.php?url=xxx to achieve short URL access.

Continue, we use the URL rewrite that overrides the function to implement such as can be accessed via address: http://yourdomain/xxx.

The following are the rewrite rules:

#Apache规则: 
rewriterule ^/(. *) $/link.php?url=$1 [L] 
 
#如果使用nginx, the rule writes: 
rewrite ^/(. *) $/link.php?url= $ last; 

Scheme 2:php+ini implement short URL technology

For Scenario 1, the advantage of using a database is ease of operation, and a large number of short URL queries need to be optimized. and Scheme 2 discard the database, use the INI configuration, we will short URLs and real URL configuration in the INI file, PHP directly through Parse_ini_file () read INI file, a few lines of code can achieve a short URL jump.
Links.ini files are configured like this:

Baidu  = https://www.baidu.com/ 
qq    = http://www.qq.com/ 
HW    = http://www.hw.com/ 
DM    = Http://www.dm.com/view-blog-362.html 

And index.php's code can write this:

$links = Parse_ini_file (' Links.ini '); 
 
if (Isset ($_get[' l ')) && array_key_exists ($_get[' l '], $links)) { 
  header (' Location: '. $links [$_get[' L ']] ); 
} 
else{ 
  header (' http/1.0 404 Not Found '); 
  Echo ' Unknown link. '; 
} 

Of course, we also need to configure the rewrite rules.

#Apache规则: 
rewriterule ^/(. *) $/index.php?l=$1 [L] 
 
#如果使用nginx, the rule writes: 
rewrite ^/(. *) $/index.php?l=$1 Last 

OK, we now visit the URL: HTTP://DEMO.JB51.NET/DM, it directly to the actual URL: http://www.jb51.net/view-blog-362.html.
In contrast, the second scheme is suitable for small applications, you can also save the URL as an array, you can do a management interface dedicated to maintain these short URLs.

The third option: the short link of the PHP version of the delivery method

<?php
function Shorturl ($input) {
$base = array (
' A ', ' B ', ' C ', ' d ', ' e ', ' f ', ' g ', ' h ', '
i ', ' j ', ') ', ' K ', ' l ', ' m ', ' n ', ' o ', ' P ',
' Q ', ' R ', ' s ', ' t ', ' u ', ' V ', ' w ', ' x ',
' y ', ' z ', ' 0 ', ' 1 ', ' 2 ', ' 3 ', ' 4 ', ' 5 '
);
 
$hex = MD5 ($input);
$hexLen = strlen ($hex);
$subHexLen = $hexLen/8;
$output = Array ();
 
for ($i = 0; $i < $subHexLen; $i + +) {
//Encrypt characters in 8-bit group 16 and 0X3FFFFFFF (30-bit 1) bitwise AND operation
$subHex = substr ($hex, $i * 8 , 8);
$int = 0X3FFFFFFF & (1 * (' 0x '. $subHex));
$out = ';
 
for ($j = 0; $j < 6; $j + +) {
 
//chars The resulting value to the 0x0000001f bitwise AND operation, obtain the character array index
$val = 0x0000001f & $int;
$out. = $base 32[$val];
$int = $int >> 5;
}
 
$output [] = $out;
}
 
return $output;
>

Summarize:

User access to short URL process:

1, browser access to the short URL http://short.cn/Xvdf23, after DNS resolution will point to the http://short.cn server.
2, the server based on the short URL of the ID field to find a database, return to the original URL.
3, redirect to the original URL returned above

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