Reprint: A very useful summary of PHP common functions

Keywords: PHP encoding Database SQL

1. PHP Encryption and Decryption

PHP encryption and decryption function can be used to encrypt some useful strings stored in the database, and through reversible decryption of strings, the function uses base64 and MD5 encryption and decryption.

function encryptDecrypt($key, $string, $decrypt){ 
    if($decrypt){ 
        $decrypted = rtrim(mcrypt_decrypt(MCRYPT_RIJNDAEL_256, md5($key), base64_decode($string), MCRYPT_MODE_CBC, md5(md5($key))), "12"); 
        return $decrypted; 
    }else{ 
        $encrypted = base64_encode(mcrypt_encrypt(MCRYPT_RIJNDAEL_256, md5($key), $string, MCRYPT_MODE_CBC, md5(md5($key)))); 
        return $encrypted; 
    } 
}

The method of use is as follows:

//The following is to encrypt and decrypt the string "Helloweba Welcome You" separately 
//Encryption: 
echo encryptDecrypt('password', 'Helloweba Welcome',0); 
//Decrypt: 
echo encryptDecrypt('password', 'z0JAx4qMwcF+db5TNbp/xwdUM84snRsXvvpXuaCa4Bk=',1);

2. PHP Generates Random Strings

When we need to generate a random name, temporary password and other strings, we can use the following functions:

function generateRandomString($length = 10) { 
    $characters = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ'; 
    $randomString = ''; 
    for ($i = 0; $i < $length; $i++) { 
        $randomString .= $characters[rand(0, strlen($characters) - 1)]; 
    } 
    return $randomString; 
}

The method of use is as follows:

echo generateRandomString(20);

3. PHP Gets File Extensions (Suffixes)
The following functions can quickly obtain the file extension, or suffix.

function getExtension($filename){ 
  $myext = substr($filename, strrpos($filename, '.')); 
  return str_replace('.','',$myext); 
}

The method of use is as follows:

$filename = 'My documents.doc'; 
echo getExtension($filename);

4. PHP Gets File Size and Formats
The following functions can be used to get the size of the file and convert it into readable formats such as KB, MB, etc.

function formatSize($size) { 
    $sizes = array(" Bytes", " KB", " MB", " GB", " TB", " PB", " EB", " ZB", " YB"); 
    if ($size == 0) {  
        return('n/a');  
    } else { 
      return (round($size/pow(1024, ($i = floor(log($size, 1024)))), 2) . $sizes[$i]);  
    } 
}

The method of use is as follows:

$thefile = filesize('test_file.mp3'); 
echo formatSize($thefile);

5. PHP Replacement Label Characters
Sometimes we need to replace the string and template tag with the specified content. We can use the following functions:

function stringParser($string,$replacer){ 
    $result = str_replace(array_keys($replacer), array_values($replacer),$string); 
    return $result; 
}

The method of use is as follows:

$string = 'The {b}anchor text{/b} is the {b}actual word{/b} or words used {br}to describe the link {br}itself'; 
$replace_array = array('{b}' => '<b>','{/b}' => '</b>','{br}' => '<br />'); 
 
echo stringParser($string,$replace_array);

6. PHP lists file names in directories
If you want to list all the files in the directory, use the following code:

function listDirFiles($DirPath){ 
    if($dir = opendir($DirPath)){ 
         while(($file = readdir($dir))!== false){ 
                if(!is_dir($DirPath.$file)) 
                { 
                    echo "filename: $file<br />"; 
                } 
         } 
    } 
}

The method of use is as follows:

listDirFiles('home/some_folder/');

7. PHP Gets the Current Page URL
The following functions get the URL of the current page, whether http or https.

function curPageURL() { 
    $pageURL = 'http'; 
    if (!empty($_SERVER['HTTPS'])) {$pageURL .= "s";} 
    $pageURL .= "://"; 
    if ($_SERVER["SERVER_PORT"] != "80") { 
        $pageURL .= $_SERVER["SERVER_NAME"].":".$_SERVER["SERVER_PORT"].$_SERVER["REQUEST_URI"]; 
    } else { 
        $pageURL .= $_SERVER["SERVER_NAME"].$_SERVER["REQUEST_URI"]; 
    } 
    return $pageURL; 
}

The method of use is as follows:

echo curPageURL();

8. PHP Mandatory Download Files
Sometimes we don't want browsers to open files directly, such as PDF files, but to download files directly. Then the following functions can force the download of files. The function uses the application/octet-stream header type.

function download($filename){ 
    if ((isset($filename))&&(file_exists($filename))){ 
       header("Content-length: ".filesize($filename)); 
       header('Content-Type: application/octet-stream'); 
       header('Content-Disposition: attachment; filename="' . $filename . '"'); 
       readfile("$filename"); 
    } else { 
       echo "Looks like file does not exist!"; 
    } 
}

The method of use is as follows:

download('/down/test_45f73e852.zip');

9. PHP Interception String Length
We often encounter the need to intercept the length of strings (including Chinese characters), such as the title display can not exceed how many characters, the length of the excess is expressed in..., the following functions can meet your needs.

/* 
 Utf-8,gb2312 Chinese character interception function supported by both 
 cut_str(String, Interception Length, Start Length, Coding; 
 Coding defaults to utf-8 
 Start length defaults to 0 
*/ 
function cutStr($string, $sublen, $start = 0, $code = 'UTF-8'){ 
    if($code == 'UTF-8'){ 
        $pa = "/[x01-x7f]|[xc2-xdf][x80-xbf]|xe0[xa0-xbf][x80-xbf]|[xe1-xef][x80-xbf][x80-xbf]|xf0[x90-xbf][x80-xbf][x80-xbf]|[xf1-xf7][x80-xbf][x80-xbf][x80-xbf]/"; 
        preg_match_all($pa, $string, $t_string); 
 
        if(count($t_string[0]) - $start > $sublen) return join('', array_slice($t_string[0], $start, $sublen))."..."; 
        return join('', array_slice($t_string[0], $start, $sublen)); 
    }else{ 
        $start = $start*2; 
        $sublen = $sublen*2; 
        $strlen = strlen($string); 
        $tmpstr = ''; 
 
        for($i=0; $i<$strlen; $i++){ 
            if($i>=$start && $i<($start+$sublen)){ 
                if(ord(substr($string, $i, 1))>129){ 
                    $tmpstr.= substr($string, $i, 2); 
                }else{ 
                    $tmpstr.= substr($string, $i, 1); 
                } 
            } 
            if(ord(substr($string, $i, 1))>129) $i++; 
        } 
        if(strlen($tmpstr)<$strlen ) $tmpstr.= "..."; 
        return $tmpstr; 
    } 
}

The method of use is as follows:

$str = "jQuery Plug-in Implementation of Loading Pictures and Page Effects"; 
echo cutStr($str,16);

10. PHP Gets Real IP of Client
We often record the user's IP with the database. The following code can obtain the client's real IP:

//Getting User Real IP 
function getIp() { 
    if (getenv("HTTP_CLIENT_IP") && strcasecmp(getenv("HTTP_CLIENT_IP"), "unknown")) 
        $ip = getenv("HTTP_CLIENT_IP"); 
    else 
        if (getenv("HTTP_X_FORWARDED_FOR") && strcasecmp(getenv("HTTP_X_FORWARDED_FOR"), "unknown")) 
            $ip = getenv("HTTP_X_FORWARDED_FOR"); 
        else 
            if (getenv("REMOTE_ADDR") && strcasecmp(getenv("REMOTE_ADDR"), "unknown")) 
                $ip = getenv("REMOTE_ADDR"); 
            else 
                if (isset ($_SERVER['REMOTE_ADDR']) && $_SERVER['REMOTE_ADDR'] && strcasecmp($_SERVER['REMOTE_ADDR'], "unknown")) 
                    $ip = $_SERVER['REMOTE_ADDR']; 
                else 
                    $ip = "unknown"; 
    return ($ip); 
}

The method of use is as follows:

echo getIp();

11. PHP Prevents SQL Injection
When we query the database, we need to filter some illegal characters to prevent malicious injection of SQL for security reasons. Look at the function:

function injCheck($sql_str) {  
    $check = preg_match('/select|insert|update|delete|'|/*|*|../|./|union|into|load_file|outfile/', $sql_str);
    if ($check) { 
        echo 'Illegal characters!!'; 
        exit; 
    } else { 
        return $sql_str; 
    } 
}

The method of use is as follows:

echo injCheck('1 or 1=1');

12. PHP Page Tips and Jump
When we do form operations, sometimes we need to prompt the user for friendly results and jump to related pages. See the following functions:

function message($msgTitle,$message,$jumpUrl){ 
    $str = '<!DOCTYPE HTML>'; 
    $str .= '<html>'; 
    $str .= '<head>'; 
    $str .= '<meta charset="utf-8">'; 
    $str .= '<title>Page prompt</title>'; 
    $str .= '<style type="text/css">'; 
    $str .= '*{margin:0; padding:0}a{color:#369; text-decoration:none;}a:hover{text-decoration:underline}body{height:100%; font:12px/18px Tahoma, Arial,  sans-serif; color:#424242; background:#fff}.message{width:450px; height:120px; margin:16% auto; border:1px solid #99b1c4; background:#ecf7fb}.message h3{height:28px; line-height:28px; background:#2c91c6; text-align:center; color:#fff; font-size:14px}.msg_txt{padding:10px; margin-top:8px}.msg_txt h4{line-height:26px; font-size:14px}.msg_txt h4.red{color:#f30}.msg_txt p{line-height:22px}'; 
    $str .= '</style>'; 
    $str .= '</head>'; 
    $str .= '<body>'; 
    $str .= '<div class="message">'; 
    $str .= '<h3>'.$msgTitle.'</h3>'; 
    $str .= '<div class="msg_txt">'; 
    $str .= '<h4 class="red">'.$message.'</h4>'; 
    $str .= '<p>System will be in <span style="color:blue;font-weight:bold">3</span> Automatic jump in seconds,If you don't want to wait,Direct click <a href="{$jumpUrl}">Here</a> Jump</p>'; 
    $str .= "<script>setTimeout('location.replace('".$jumpUrl."')',2000)</script>"; 
    $str .= '</div>'; 
    $str .= '</div>'; 
    $str .= '</body>'; 
    $str .= '</html>'; 
    echo $str; 
}

The method of use is as follows:

message('Operation hint','Successful operation!','https://segmentfault.com/');

13. PHP Computing Time
When we process time, we need to calculate the current time distance from a certain point of time, such as computing the client run time, usually expressed in hh:mm:ss.

function changeTimeType($seconds) { 
    if ($seconds > 3600) { 
        $hours = intval($seconds / 3600); 
        $minutes = $seconds % 3600; 
        $time = $hours . ":" . gmstrftime('%M:%S', $minutes); 
    } else { 
        $time = gmstrftime('%H:%M:%S', $seconds); 
    } 
    return $time; 
}

The method of use is as follows:

$seconds = 3712; 
echo changeTimeType($seconds);

I hope this article will be helpful to everyone's PHP program design.
Below, I would like to add some information for you. I hope you like it.
This article summarizes commonly used PHP functions, including acquiring client IP, string interception, download, etc. For details, please see the following code:

<?php
/**
 * Get client IP
 * @return [string] [description]
 */
function getClientIp() {
 $ip = NULL;
 if (isset($_SERVER['HTTP_X_FORWARDED_FOR'])) {
  $arr = explode(',', $_SERVER['HTTP_X_FORWARDED_FOR']);
  $pos = array_search('unknown',$arr);
  if(false !== $pos) unset($arr[$pos]);
  $ip = trim($arr[0]);
 }elseif (isset($_SERVER['HTTP_CLIENT_IP'])) {
  $ip = $_SERVER['HTTP_CLIENT_IP'];
 }elseif (isset($_SERVER['REMOTE_ADDR'])) {
  $ip = $_SERVER['REMOTE_ADDR'];
 }
 // IP address validation
 $ip = (false !== ip2long($ip)) ? $ip : '0.0.0.0';
 return $ip;
}
 
/**
 * Getting Online IP
 * @return String
 */
function getOnlineIp($format=0) {
 global $S_GLOBAL;
 if(empty($S_GLOBAL['onlineip'])) {
  if(getenv('HTTP_CLIENT_IP') && strcasecmp(getenv('HTTP_CLIENT_IP'), 'unknown')) {
   $onlineip = getenv('HTTP_CLIENT_IP');
  } elseif(getenv('HTTP_X_FORWARDED_FOR') && strcasecmp(getenv('HTTP_X_FORWARDED_FOR'), 'unknown')) {
   $onlineip = getenv('HTTP_X_FORWARDED_FOR');
  } elseif(getenv('REMOTE_ADDR') && strcasecmp(getenv('REMOTE_ADDR'), 'unknown')) {
   $onlineip = getenv('REMOTE_ADDR');
  } elseif(isset($_SERVER['REMOTE_ADDR']) && $_SERVER['REMOTE_ADDR'] && strcasecmp($_SERVER['REMOTE_ADDR'], 'unknown')) {
   $onlineip = $_SERVER['REMOTE_ADDR'];
  }
  preg_match("/[\d\.]{7,15}/", $onlineip, $onlineipmatches);
  $S_GLOBAL['onlineip'] = $onlineipmatches[0] ? $onlineipmatches[0] : 'unknown';
 }
 
 if($format) {
  $ips = explode('.', $S_GLOBAL['onlineip']);
  for($i=0;$i<3;$i++) {
   $ips[$i] = intval($ips[$i]);
  }
  return sprintf('%03d%03d%03d', $ips[0], $ips[1], $ips[2]);
 } else {
  return $S_GLOBAL['onlineip'];
 }
}
 
 
 
/**
 * Get url
 * @return [type] [description]
 */
function getUrl(){
 $pageURL = 'http';
 if (isset($_SERVER["HTTPS"]) && $_SERVER["HTTPS"] == "on") {
 $pageURL .= "s";
 }
 $pageURL .= "://";
 if ($_SERVER["SERVER_PORT"] != "80") {
 $pageURL .= $_SERVER["HTTP_HOST"] . ":" . $_SERVER["SERVER_PORT"] . $_SERVER["REQUEST_URI"];
 } else {
 $pageURL .= $_SERVER["HTTP_HOST"] . $_SERVER["REQUEST_URI"];
 }
 return $pageURL;
}
 
/**
 * Get the root directory of the access path for the current site
 * @return [type] [description]
 */
function getSiteUrl() {
 $uri = $_SERVER['REQUEST_URI']?$_SERVER['REQUEST_URI']:($_SERVER['PHP_SELF']?$_SERVER['PHP_SELF']:$_SERVER['SCRIPT_NAME']);
 return 'http://'.$_SERVER['HTTP_HOST'].substr($uri, 0, strrpos($uri, '/')+1);
}
 
 
 
/**
 * String interception, supporting Chinese and other encoding
 * @param [string] $str  [String]
 * @param integer $start [Starting position]
 * @param integer $length [Interception length]
 * @param string $charset [String encoding]
 * @param boolean $suffix [Is there an ellipsis?
 * @return [type]   [description]
 */
function msubstr($str, $start=0, $length=15, $charset="utf-8", $suffix=true) {
 if(function_exists("mb_substr")) {
  return mb_substr($str, $start, $length, $charset);
 } elseif(function_exists('iconv_substr')) {
  return iconv_substr($str,$start,$length,$charset);
 }
 $re['utf-8'] = "/[\x01-\x7f]|[\xc2-\xdf][\x80-\xbf]|[\xe0-\xef][\x80-\xbf]{2}|[\xf0-\xff][\x80-\xbf]{3}/";
 $re['gb2312'] = "/[\x01-\x7f]|[\xb0-\xf7][\xa0-\xfe]/";
 $re['gbk'] = "/[\x01-\x7f]|[\x81-\xfe][\x40-\xfe]/";
 $re['big5'] = "/[\x01-\x7f]|[\x81-\xfe]([\x40-\x7e]|\xa1-\xfe])/";
 preg_match_all($re[$charset], $str, $match);
 $slice = join("",array_slice($match[0], $start, $length));
 if($suffix) {
  return $slice."…";
 }
 return $slice;
}
 
/**
 * php Implementing js escape function
 * @param [type] $string [description]
 * @param string $encoding [description]
 * @return [type]   [description]
 */
function escape($string, $encoding = 'UTF-8'){
 $return = null;
 for ($x = 0; $x < mb_strlen($string, $encoding);$x ++)
 {
 $str = mb_substr($string, $x, 1, $encoding);
 if (strlen($str) > 1) { // multiple-byte character
  $return .= "%u" . strtoupper(bin2hex(mb_convert_encoding($str, 'UCS-2', $encoding)));
 } else {
  $return .= "%" . strtoupper(bin2hex($str));
 }
 }
 return $return;
}
/**
 * php Implementing js unescape function
 * @param [type] $str [description]
 * @return [type]  [description]
 */
function unescape($str) {
 $str = rawurldecode($str);
 preg_match_all("/(?:%u.{4})|.{4};|&#\d+;|.+/U",$str,$r);
 $ar = $r[0];
 foreach($ar as $k=>$v) {
  if(substr($v,0,2) == "%u"){
   $ar[$k] = iconv("UCS-2","utf-8//IGNORE",pack("H4",substr($v,-4)));
  } elseif(substr($v,0,3) == "") {
   $ar[$k] = iconv("UCS-2","utf-8",pack("H4",substr($v,3,-1)));
  } elseif(substr($v,0,2) == "&#") {
   echo substr($v,2,-1)."";
   $ar[$k] = iconv("UCS-2","utf-8",pack("n",substr($v,2,-1)));
  }
 }
 return join("",$ar);
}
 
/**
 * Digital rename
 * @param [type] $num [description]
 * @return [type]  [description]
 */
function num2rmb ($num) {
 $c1 = "One hundred and fifty-five people were enlisted by Lu Xu.";
 $c2 = "Dividing the corners to collect hundreds of thousands and hundreds of millions";
 $num = round($num, 2);
 $num = $num * 100;
 if (strlen($num) > 10) {
  return "oh,sorry,the number is too long!";
 }
 $i = 0;
 $c = "";
 while (1) {
  if ($i == 0) {
   $n = substr($num, strlen($num)-1, 1);
  } else {
   $n = $num % 10;
  }
  $p1 = substr($c1, 3 * $n, 3);
  $p2 = substr($c2, 3 * $i, 3);
  if ($n != '0' || ($n == '0' && ($p2 == 'Billion' || $p2 == 'ten thousand' || $p2 == 'element'))) {
   $c = $p1 . $p2 . $c;
  } else {
   $c = $p1 . $c;
  }
  $i = $i + 1;
  $num = $num / 10;
  $num = (int)$num;
  if ($num == 0) {
   break;
  }
 }
 $j = 0;
 $slen = strlen($c);
 while ($j < $slen) {
  $m = substr($c, $j, 6);
  if ($m == 'Zero element' || $m == 'Zero' || $m == 'Zero' || $m == '00') {
   $left = substr($c, 0, $j);
   $right = substr($c, $j + 3);
   $c = $left . $right;
   $j = $j-3;
   $slen = $slen-3;
  }
  $j = $j + 3;
 }
 if (substr($c, strlen($c)-3, 3) == 'Zero') {
  $c = substr($c, 0, strlen($c)-3);
 } // if there is a '0' on the end , chop it out
 return $c . "whole";
}
 
/**
 * Special Characters
 * @param [type] $str [description]
 * @return [type]  [description]
 */
function makeSemiangle($str) {
 $arr = array(
  '０' => '0', '１' => '1', '２' => '2', '３' => '3', '４' => '4',
  '５' => '5', '６' => '6', '７' => '7', '８' => '8', '９' => '9',
  'Ａ' => 'A', 'Ｂ' => 'B', 'Ｃ' => 'C', 'Ｄ' => 'D', 'Ｅ' => 'E',
  'Ｆ' => 'F', 'Ｇ' => 'G', 'Ｈ' => 'H', 'Ｉ' => 'I', 'Ｊ' => 'J',
  'Ｋ' => 'K', 'Ｌ' => 'L', 'Ｍ' => 'M', 'Ｎ' => 'N', 'Ｏ' => 'O',
  'Ｐ' => 'P', 'Ｑ' => 'Q', 'Ｒ' => 'R', 'Ｓ' => 'S', 'Ｔ' => 'T',
  'Ｕ' => 'U', 'Ｖ' => 'V', 'Ｗ' => 'W', 'Ｘ' => 'X', 'Ｙ' => 'Y',
  'Ｚ' => 'Z', 'ａ' => 'a', 'ｂ' => 'b', 'ｃ' => 'c', 'ｄ' => 'd',
  'ｅ' => 'e', 'ｆ' => 'f', 'ｇ' => 'g', 'ｈ' => 'h', 'ｉ' => 'i',
  'ｊ' => 'j', 'ｋ' => 'k', 'ｌ' => 'l', 'ｍ' => 'm', 'ｎ' => 'n',
  'ｏ' => 'o', 'ｐ' => 'p', 'ｑ' => 'q', 'ｒ' => 'r', 'ｓ' => 's',
  'ｔ' => 't', 'ｕ' => 'u', 'ｖ' => 'v', 'ｗ' => 'w', 'ｘ' => 'x',
  'ｙ' => 'y', 'ｚ' => 'z',
  '(' => '(', ')' => ')', '〔' => '[', '〕' => ']', '[' => '[',
  ']' => ']', '〖' => '[', '〗' => ']', '｛' => '{', '｝' => '}', '<' => '<',
  '>' => '>',
  '％' => '%', '＋' => '+', '—' => '-', '－' => '-', '～' => '-',
  ': ' => ':', '. ' => '.', ',' => ',', '，' => '.', ',' => '.',
  '；' => ';', '？' => '?', '!' => '!', '…' => '-', '‖' => '|',
  '"' => '"', '"' => '"', ''' => '`', ''' => '`', '｜' => '|', '〃' => '"',
  '　' => ' ','．' => '.');
 return strtr($str, $arr);
}
 
/**
 * download
 * @param [type] $filename [description]
 * @param string $dir  [description]
 * @return [type]   [description]
 */
function downloads($filename,$dir='./'){
 $filepath = $dir.$filename;
 if (!file_exists($filepath)){
  header("Content-type: text/html; charset=utf-8");
  echo "File not found!";
  exit;
 } else {
  $file = fopen($filepath,"r");
  Header("Content-type: application/octet-stream");
  Header("Accept-Ranges: bytes");
  Header("Accept-Length: ".filesize($filepath));
  Header("Content-Disposition: attachment; filename=".$filename);
  echo fread($file, filesize($filepath));
  fclose($file);
 }
}
 
/**
 * Create a directory tree
 * @param [type] $dir [description]
 * @param integer $mode [description]
 * @return [type]  [description]
 */
function mkdirs($dir, $mode = 0777) {
 if (!is_dir($dir)) {
  mkdirs(dirname($dir), $mode);
  return mkdir($dir, $mode);
 }
 return true;
}

Posted by captainplanet17 on Fri, 19 Apr 2019 22:18:33 -0700

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