从discuz里面拿来的东东[转phpx]

<?php
加解密函数

$encode = authocode('我要加密','ENCODE');

$decode = authocode('我要解密','DECODE');

$auth_key = 34577 ; //密钥
function authcode($string, $operation, $key = '') {

    $key = md5($key ? $key : $GLOBALS['auth_key']);
    $key_length = strlen($key);

    $string = $operation == 'DECODE' ? base64_decode($string) : substr(md5($string.$key), 0, 8).$string;
    $string_length = strlen($string);

    $rndkey = $box = array();
    $result = '';

    for($i = 0; $i <= 255; $i++) {
        $rndkey[$i] = ord($key[$i % $key_length]);
        $box[$i] = $i;
    }

    for($j = $i = 0; $i < 256; $i++) {
        $j = ($j + $box[$i] + $rndkey[$i]) % 256;
        $tmp = $box[$i];
        $box[$i] = $box[$j];
        $box[$j] = $tmp;
    }

    for($a = $j = $i = 0; $i < $string_length; $i++) {
        $a = ($a + 1) % 256;
        $j = ($j + $box[$a]) % 256;
        $tmp = $box[$a];
        $box[$a] = $box[$j];
        $box[$j] = $tmp;
        $result .= chr(ord($string[$i]) ^ ($box[($box[$a] + $box[$j]) % 256]));
    }

    if($operation == 'DECODE') {
        if(substr($result, 0, 8) == substr(md5(substr($result, 8).$key), 0, 8)) {
            return substr($result, 8);
        } else {
            return '';
        }
    } else {
        return str_replace('=', '', base64_encode($result));
    }

}

?>

<?php
字符串截取函数

$cutstr =  cutstr('截取我,hahahahahaaha','3');

function cutstr($string, $length, $dot = ' ...') {
    global $charset;

    if(strlen($string) <= $length) {
        return $string;
    }

    $string = str_replace(array('&', '"', '<', '>'), array('&', '"', '<', '>'), $string);

    $strcut = '';
    if(strtolower($charset) == 'utf-8') {

        $n = $tn = $noc = 0;
        while($n < strlen($string)) {

            $t = ord($string[$n]);
            if($t == 9 || $t == 10 || (32 <= $t && $t <= 126)) {
                $tn = 1; $n++; $noc++;
            } elseif(194 <= $t && $t <= 223) {
                $tn = 2; $n += 2; $noc += 2;
            } elseif(224 <= $t && $t < 239) {
                $tn = 3; $n += 3; $noc += 2;
            } elseif(240 <= $t && $t <= 247) {
                $tn = 4; $n += 4; $noc += 2;
            } elseif(248 <= $t && $t <= 251) {
                $tn = 5; $n += 5; $noc += 2;
            } elseif($t == 252 || $t == 253) {
                $tn = 6; $n += 6; $noc += 2;
            } else {
                $n++;
            }

            if($noc >= $length) {
                break;
            }

        }
        if($noc > $length) {
            $n -= $tn;
        }

        $strcut = substr($string, 0, $n);

    } else {
        for($i = 0; $i < $length - strlen($dot) - 1; $i++) {
            $strcut .= ord($string[$i]) > 127 ? $string[$i].$string[++$i] : $string[$i];
        }
    }

    $strcut = str_replace(array('&', '"', '<', '>'), array('&', '"', '<', '>'), $strcut);

    return $strcut.$dot;
}
function daddslashes($string, $force = 0) {
    !defined('MAGIC_QUOTES_GPC') && define('MAGIC_QUOTES_GPC', get_magic_quotes_gpc());
    if(!MAGIC_QUOTES_GPC || $force) {
        if(is_array($string)) {
            foreach($string as $key => $val) {
                $string[$key] = daddslashes($val, $force);
            }
        } else {
            $string = addslashes($string);
        }
    }
    return $string;
}
?>

<?php

生成随机数的函数
function random($length, $numeric = 0) {
    PHP_VERSION < '4.2.0' && mt_srand((double)microtime() * 1000000);
    if($numeric) {
        $hash = sprintf('%0'.$length.'d', mt_rand(0, pow(10, $length) - 1));
    } else {
        $hash = '';
        $chars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789abcdefghijklmnopqrstuvwxyz';
        $max = strlen($chars) - 1;
        for($i = 0; $i < $length; $i++) {
            $hash .= $chars[mt_rand(0, $max)];
        }
    }
    return $hash;
}

?>

<?php
// discuz 一个ip转换地址的函数 wry.dat 是ip数据库可以从纯真网下载最新的 [url]http://www.cz88.net/[/url]

function convertip($ip) {
    if(!preg_match("/^d{1,3}.d{1,3}.d{1,3}.d{1,3}$/", $ip)) {
        return '';
    }

    if($fd = @fopen(DISCUZ_ROOT.'./ipdata/wry.dat', 'rb')) {

        $ip = explode('.', $ip);
        $ipNum = $ip[0] * 16777216 + $ip[1] * 65536 + $ip[2] * 256 + $ip[3];

        $DataBegin = fread($fd, 4);
        $DataEnd = fread($fd, 4);
        $ipbegin = implode('', unpack('L', $DataBegin));
        if($ipbegin < 0) $ipbegin += pow(2, 32);
        $ipend = implode('', unpack('L', $DataEnd));
        if($ipend < 0) $ipend += pow(2, 32);
        $ipAllNum = ($ipend - $ipbegin) / 7 + 1;

        $BeginNum = 0;
        $EndNum = $ipAllNum;

        while($ip1num > $ipNum || $ip2num < $ipNum) {
            $Middle= intval(($EndNum + $BeginNum) / 2);

            fseek($fd, $ipbegin + 7 * $Middle);
            $ipData1 = fread($fd, 4);
            if(strlen($ipData1) < 4) {
                fclose($fd);
                return 'System Error';
            }
            $ip1num = implode('', unpack('L', $ipData1));
            if($ip1num < 0) $ip1num += pow(2, 32);

            if($ip1num > $ipNum) {
                $EndNum = $Middle;
                continue;
            }

            $DataSeek = fread($fd, 3);
            if(strlen($DataSeek) < 3) {
                fclose($fd);
                return 'System Error';
            }
            $DataSeek = implode('', unpack('L', $DataSeek.chr(0)));
            fseek($fd, $DataSeek);
            $ipData2 = fread($fd, 4);
            if(strlen($ipData2) < 4) {
                fclose($fd);
                return 'System Error';
            }
            $ip2num = implode('', unpack('L', $ipData2));
            if($ip2num < 0) $ip2num += pow(2, 32);

            if($ip2num < $ipNum) {
                if($Middle == $BeginNum) {
                    fclose($fd);
                    return 'Unknown';
                }
                $BeginNum = $Middle;
            }
        }

        $ipFlag = fread($fd, 1);
        if($ipFlag == chr(1)) {
            $ipSeek = fread($fd, 3);
            if(strlen($ipSeek) < 3) {
                fclose($fd);
                return 'System Error';
            }
            $ipSeek = implode('', unpack('L', $ipSeek.chr(0)));
            fseek($fd, $ipSeek);
            $ipFlag = fread($fd, 1);
        }

        if($ipFlag == chr(2)) {
            $AddrSeek = fread($fd, 3);
            if(strlen($AddrSeek) < 3) {
                fclose($fd);
                return 'System Error';
            }
            $ipFlag = fread($fd, 1);
            if($ipFlag == chr(2)) {
                $AddrSeek2 = fread($fd, 3);
                if(strlen($AddrSeek2) < 3) {
                    fclose($fd);
                    return 'System Error';
                }
                $AddrSeek2 = implode('', unpack('L', $AddrSeek2.chr(0)));
                fseek($fd, $AddrSeek2);
            } else {
                fseek($fd, -1, SEEK_CUR);
            }

            while(($char = fread($fd, 1)) != chr(0))
                $ipAddr2 .= $char;

            $AddrSeek = implode('', unpack('L', $AddrSeek.chr(0)));
            fseek($fd, $AddrSeek);

            while(($char = fread($fd, 1)) != chr(0))
                $ipAddr1 .= $char;
        } else {
            fseek($fd, -1, SEEK_CUR);
            while(($char = fread($fd, 1)) != chr(0))
                $ipAddr1 .= $char;

            $ipFlag = fread($fd, 1);
            if($ipFlag == chr(2)) {
                $AddrSeek2 = fread($fd, 3);
                if(strlen($AddrSeek2) < 3) {
                    fclose($fd);
                    return 'System Error';
                }
                $AddrSeek2 = implode('', unpack('L', $AddrSeek2.chr(0)));
                fseek($fd, $AddrSeek2);
            } else {
                fseek($fd, -1, SEEK_CUR);
            }
            while(($char = fread($fd, 1)) != chr(0))
                $ipAddr2 .= $char;
        }
        fclose($fd);

        if(preg_match('/http/i', $ipAddr2)) {
            $ipAddr2 = '';
        }
        $ipaddr = "$ipAddr1 $ipAddr2";
        $ipaddr = preg_replace('/CZ88.NET/is', '', $ipaddr);
        $ipaddr = preg_replace('/^s*/is', '', $ipaddr);
        $ipaddr = preg_replace('/s*$/is', '', $ipaddr);
        if(preg_match('/http/i', $ipaddr) || $ipaddr == '') {
            $ipaddr = 'Unknown';
        }

        return $ipaddr;

    } else {

        $datadir = DISCUZ_ROOT.'./ipdata/';
        $ip_detail = explode('.', $ip);
        if(file_exists($datadir.$ip_detail[0].'.txt')) {
            $ip_fdata = @fopen($datadir.$ip_detail[0].'.txt', 'r');
        } else {
            if(!($ip_fdata = @fopen($datadir.'0.txt', 'r'))) {
                return 'Invalid IP data file';
            }
        }
        for ($i = 0; $i <= 3; $i++) {
            $ip_detail[$i] = sprintf('%03d', $ip_detail[$i]);
        }
        $ip = join('.', $ip_detail);
        do {
            $ip_data = fgets($ip_fdata, 200);
            $ip_data_detail = explode('|', $ip_data);
            if($ip >= $ip_data_detail[0] && $ip <= $ip_data_detail[1]) {
                fclose($ip_fdata);
                return $ip_data_detail[2].$ip_data_detail[3];
            }
        } while(!feof($ip_fdata));
        fclose($ip_fdata);
        return 'UNKNOWN';

    }

}
?>