本文实例总结了一些在php应用开发中常用到的函数,这些函数有字符操作,文件操作及其它的一些操作了,分享给大家供大家参考。具体如下:
1、PHP加密解密
PHP加密和解密函数可以用来加密一些有用的字符串存放在数据库里,并且通过可逆解密字符串,该函数使用了base64和MD5加密和解密。
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;
}
}
使用方法如下:
//加密:
echo encryptDecrypt('password', 'Helloweba欢迎您',0);
//解密:
echo encryptDecrypt('password', 'z0JAx4qMwcF+db5TNbp/xwdUM84snRsXvvpXuaCa4Bk=',1);
2、PHP生成随机字符串
当我们需要生成一个随机名字,临时密码等字符串时可以用到下面的函数:
$characters = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
$randomString = '';
for ($i = 0; $i < $length; $i++) {
$randomString .= $characters[rand(0, strlen($characters) - 1)];
}
return $randomString;
}
使用方法如下:
3、PHP获取文件扩展名(后缀)
以下函数可以快速获取文件的扩展名即后缀。
$myext = substr($filename, strrpos($filename, '.'));
return str_replace('.','',$myext);
}
使用方法如下:
echo getExtension($filename);
4、PHP获取文件大小并格式化
以下使用的函数可以获取文件的大小,并且转换成便于阅读的KB,MB等格式。
$sizes = array(" Bytes", " KB", " MB", " GB", " TB", " PB", " EB", " ZB", " YB");
if ($size == 0) {
return('n/a');
} else {
return (round($size/pow(1024, ($i = floor(log($size, 1024)))), 2) . $sizes[$i]);
}
}
使用方法如下:
echo formatSize($thefile);
5、PHP替换标签字符
有时我们需要将字符串、模板标签替换成指定的内容,可以用到下面的函数:
$result = str_replace(array_keys($replacer), array_values($replacer),$string);
return $result;
}
使用方法如下:
$replace_array = array('{b}' => '<b>','{/b}' => '</b>','{br}' => '<br />');
echo stringParser($string,$replace_array);
6、PHP列出目录下的文件名
如果你想列出目录下的所有文件,使用以下代码即可:
if($dir = opendir($DirPath)){
while(($file = readdir($dir))!== false){
if(!is_dir($DirPath.$file))
{
echo "filename: $file<br />";
}
}
}
}
使用方法如下:
7、PHP获取当前页面URL
以下函数可以获取当前页面的URL,不管是http还是https。
$pageURL = 'http';
if (!empty($_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 $pageURL;
}
使用方法如下:
8、PHP强制下载文件
有时我们不想让浏览器直接打开文件,如PDF文件,而是要直接下载文件,那么以下函数可以强制下载文件,函数中使用了application/octet-stream头类型。
if ((isset($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!";
}
}
使用方法如下:
9、PHP截取字符串长度
我们经常会遇到需要截取字符串(含中文汉字)长度的情况,比如标题显示不能超过多少字符,超出的长度用...表示,以下函数可以满足你的需求。
Utf-8、gb2312都支持的汉字截取函数
cut_str(字符串, 截取长度, 开始长度, 编码);
编码默认为 utf-8
开始长度默认为 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 $tmpstr;
}
}
使用方法如下:
echo cutStr($str,16);
10、PHP获取客户端真实IP
我们经常要用数据库记录用户的IP,以下代码可以获取客户端真实的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);
}
使用方法如下:
11、PHP防止SQL注入
我们在查询数据库时,出于安全考虑,需要过滤一些非法字符防止SQL恶意注入,请看一下函数:
$check = preg_match('/select|insert|update|delete|'|/*|*|../|./|union|into|load_file|outfile/', $sql_str);
if ($check) {
echo '非法字符!!';
exit;
} else {
return $sql_str;
}
}
使用方法如下:
12、PHP页面提示与跳转
我们在进行表单操作时,有时为了友好需要提示用户操作结果,并跳转到相关页面,请看以下函数:
$str = '<!DOCTYPE HTML>';
$str .= '<html>';
$str .= '<head>';
$str .= '<meta charset="utf-8">';
$str .= '<title>页面提示</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>';
$str .= '<p>系统将在 <span style="color:blue;font-weight:bold">3</span> 秒后自动跳转,如果不想等待,直接点击 <a href="{$jumpUrl}">这里</a> 跳转</p>';
$str .= "<script>setTimeout('location.replace('".$jumpUrl."')',2000)</script>";
$str .= '</div>';
$str .= '</div>';
$str .= '</body>';
$str .= '</html>';
echo $str;
}
使用方法如下:
13、PHP计算时长
我们在处理时间时,需要计算当前时间距离某个时间点的时长,如计算客户端运行时长,通常用hh:mm:ss表示。
if ($seconds > 3600) {
$hours = intval($seconds / 3600);
$minutes = $seconds % 3600;
$time = $hours . ":" . gmstrftime('%M:%S', $minutes);
} else {
$time = gmstrftime('%H:%M:%S', $seconds);
}
return $time;
}
使用方法如下:
echo changeTimeType($seconds);
希望本文所述对大家的PHP程序设计有所帮助。
下面特为大家加点料希望大家能喜欢:
本文汇总了常用的PHP函数,包括获取客户端IP,字符串截取,下载等,详情请查看如下代码:
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<?php /** * 获取客户端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地址合法验证 $ip = (false !== ip2long ( $ip )) ? $ip : '0.0.0.0' ; return $ip ; } /** * 获取在线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' ]; } } /** * 获取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 ; } /** * 获取当前站点的访问路径根目录 * @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); } /** * 字符串截取,支持中文和其他编码 * @param [string] $str [字符串] * @param integer $start [起始位置] * @param integer $length [截取长度] * @param string $charset [字符串编码] * @param boolean $suffix [是否有省略号] * @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 实现js escape 函数 * @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) { // 多字节字符 $return .= "%u" . strtoupper (bin2hex(mb_convert_encoding( $str , 'UCS-2' , $encoding ))); } else { $return .= "%" . strtoupper (bin2hex( $str )); } } return $return ; } /** * php 实现 js unescape函数 * @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 ); } /** * 数字转人名币 * @param [type] $num [description] * @return [type] [description] */ function num2rmb ( $num ) { $c1 = "零壹贰叁肆伍陆柒捌玖" ; $c2 = "分角元拾佰仟万拾佰仟亿" ; $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 == '亿' || $p2 == '万' || $p2 == '元' ))) { $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 == '零元' || $m == '零万' || $m == '零亿' || $m == '零零' ) { $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) == '零' ) { $c = substr ( $c , 0, strlen ( $c )-3); } // if there is a '0' on the end , chop it out return $c . "整" ; } /** * 特殊的字符 * @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 ); } /** * 下载 * @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 ); } } /** * 创建一个目录树 * @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; } |