使用php重新实现PHP脚本引擎内置函数

if (strchr($str, $substr) == false)
return false;

for ($i=0; $i<=($m-$n 1); $i )
{
$i = strchr($str, $substr);
$str = str_delete($str, $i, $n);
$str = str_insert($str, $i, $newstr);
}
return $str;
}
// }}}

/************ 以下串处理函数是PHP中没有的，自己写着玩 ***************/

// {{{ insert_str(), delete_str(), index_str()
/**
* Basic string operate
*
* @param string $str need get sub string variable
* @param int $start start get sub string
* @param int $length need get string length
* @return string return sub string
* @version v0.1
* @create 2005-5-24
* @modified 2005-5-24
* @author heiyeluren <hyeiyeluren@163.com>
*/
function str_insert($str, $i, $substr)
{

for($j=0; $j<$i; $j )
{
$startstr .= $str[$j];
}

for ($j=$i; $j<strlen($str); $j )
{
$laststr .= $str[$j];
}
$str = ($startstr . $substr . $laststr);

return $str;
}

function str_delete($str, $i, $j)
{
for ($c=0; $c<$i; $c )
{
$startstr .= $str[$c];
}

for ($c=($i $j); $c<strlen($str); $c )
{
$laststr .= $str[$c];
}

$str = ($startstr . $laststr);

return $str;
}
// }}}

// {{{ strcpy()
/**
* Use designate sub string replace string
*
* @param string $str need get sub string variable
* @param int $start start get sub string
* @param int $length need get string length
* @return string return sub string
* @version v0.1
* @create 2005-5-27
* @modified 2005-5-27
* @author heiyeluren <hyeiyeluren@163.com>
*/
function strcpy($s1, $s2)
{
if (strlen($s1) == NULL)
return;
if (!isset($s2))
return;

for ($i=0; $i<strlen($s1); $i )
{
$s2[] = $s1[$i];
}
return $s2;
}
// }}}

// {{{ strcat()
/**
* Use designate sub string replace string
*
* @param string $str need get sub string variable
* @param int $start start get sub string
* @param int $length need get string length
* @return string return sub string
* @version v0.1
* @create 2005-5-27
* @modified 2005-5-27
* @author heiyeluren <hyeiyeluren@163.com>
*/
function strcat($s1, $s2)
{
if (!isset($s1))
return;
if (!isset($s2))
return;

$newstr = $s1 . $s2;

return $newsstr;
}
// }}}

// {{{ php_encode(), php_decode()
/**
* Simple string encode/decode function
*
* @param string $str need code/encode string variable
* @return string code/encode after string
* @version v0.2
* @create 2005-3-11
* @modified 2005-5-24
* @author heiyeluren <hyeiyeluren@163.com>
*/

/* String encode function */
function php_encode($str)
{
if ($str=='' && strlen($str)>128)
return false;

for($i=0; $i<strlen($str); $i )
{
$c = ord($str[$i]);
if ($c>31 && $c<107)
$c = 20;
if ($c>106 && $c<127)
$c -= 75;
$word = chr($c);

$s .= $word;
}
return $s;
}

/* String decode function */
function php_decode($str)
{
if ($str=='' && strlen($str)>128)
return false;

for($i=0; $i<strlen($str); $i )
{
$c = ord($word);
if ($c>106 && $c<127)
$c = $c-20;
if ($c>31 && $c<107)
$c = $c 75;
$word = chr($c);

$s .= $word;
}
return $s;
}
// }}}

// {{{ php_encrypt(), php_decrypt()
/**
* Simple string encrypt/decrypt function
*
* @param string $str need crypt string variable
* @return string encrypt/decrypt after string
* @version v0.1
* @create 2005-5-27
* @modified 2005-5-29
* @author heiyeluren <hyeiyeluren@163.com>
*/

/* define crypt key */
$encrypt_key = 'abcdefghijklmnopqrstuvwxyz1234567890';
$decrypt_key = 'ngzqtcobmuhelkpdawxfyivrsj2468021359';

/* String encrypt function */
function php_encrypt($str)
{
global $encrypt_key, $decrypt_key;

if (strlen($str) == 0)
return false;

for ($i=0; $i<strlen($str); $i )
{
for ($j=0; $j<strlen($encrypt_key); $j )
{
if ($str[$i] == $encrypt_key[$j])
{
$enstr .= $decrypt_key[$j];
break;
}
}
}
return $enstr;
}

/* String decrypt function */
function php_decrypt($str)
{
global $encrypt_key, $decrypt_key;

if (strlen($str) == 0)
return false;

for ($i=0; $i<strlen($str); $i )
{
for ($j=0; $j<strlen($decrypt_key); $j )
{
if ($str[$i] == $decrypt_key[$j])
{
$enstr .= $encrypt_key[$j];
break;
}
}
}
return $enstr;

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