//?實(shí)在無聊,突發(fā)奇想,想把PHP里面部分已經(jīng)提供封裝好的函數(shù)重新使用PHP實(shí)現(xiàn)一遍,?
//?于是便有了下面的代碼主要實(shí)現(xiàn)了PHP中部分字符串處理函數(shù),同時(shí)實(shí)現(xiàn)了一些PHP中?
//?沒有,但是同樣有作用的字符串處理函數(shù)同樣的這些函數(shù),也能夠使用其他語言來實(shí)??
//?現(xiàn),比如用C/VBScript/Perl等等,那么你就能夠有一個(gè)自己的函數(shù)庫.??????????????
//?以下函數(shù)不一定能夠成功運(yùn)行,只是為了學(xué)習(xí)而已。?????????????????????????????
//???????????????????????????????????????????????????????????????????????????
//?如果無特別聲明,全部是由于heiyeluren原創(chuàng),要使用任何函數(shù)都請(qǐng)保留作者信息????


/**
?*?String?Functions?Reconstruct?
?*
?*?Copyright?(c)?2005?heiyeluren?
?*?Author:?heiyeluren?

?*?$Id:?StringFunctions.php,v?0.1?e?2005-5-29?23:21?heiyeluren?Exp?$
**/


//?{{{?strlen()
/**
?*?Count?string?length
?*
?*?@param?string?$str?need?count?length?string?variable?
?*?@return?int????return?count?result
?*?@version?v0.1
?*?@create?2005-5-24
?*?@modified?2005-5-24?
?*?@author?heiyeluren?
?*/
function?strlen1($str)
{
?if?($str?==?'')
??return?0;

?$count?=?0;
?while?(1)
?{
??if?($str[$count]?!=?NULL)
??{
???$count++;
???continue;
??}
??else
???break;
?}
?return?$count;
}
//?}}}


//?{{{?substr()
/**
?*?Get?sub?string
?*
?*?@param?string?$str?need?get?sub?string?variable
?*?@param?int??$start?start?get?sub?string
?*?@param?int??$length?need?get?string?length
?*?@return?string???return?sub?string
?*?@version?v0.2
?*?@create?2005-5-24
?*?@modified?2005-5-25?
?*?@author?heiyeluren?
?*/
function?substr1($str,?$start,?$length=0)
{
?if?($str?==?'')
??return;
?if?($start?>?strlen($str))
??return;
?if?(($length?!=?NULL)?&&?($start?>?0)?&&?($length?>?strlen($str)-$start))
??return;
?if?(($length?!=?NULL)?&&?($start??strlen($str)+$start))
??return;

?if?($length?==?NULL)
??$length?=?(strlen($str)?-?$start);

?if?($start??{
??for?($i=(strlen($str)+$start);?$i??{
???$substr?.=?$str[$i];
??}
?}

?if?($length?>?0)
?{
??for?($i=$start;?$i??{
???$substr?.=?$str[$i];
??}
?}

?if?($length??{
??for?($i=$start;?$i??{
???$substr?.=?$str[$i];
??}
?}
?return?$substr;
}
//?}}}


//?{{{?strrev()
/**
?*?Reversal?string?order
?*
?*?@param?string?$str?need?reversal?string?variable
?*?@return?string???reversal?string
?*?@version?v0.1
?*?@create?2005-5-24
?*?@modified?2005-5-24?
?*?@author?heiyeluren?
?*/
function?strrev1($str)
{
?if?($str?==?'')?
??return?0;
?for?($i=(strlen($str)-1);?$i>=0;?$i--)
?{
??$rev_str?.=?$str[$i];
?}
?return?$rev_str;
}
//?}}}


//?{{{?strcmp()
/**
?*?String?comparison
?*
?*?@param?string?$s1?first?string
?*?@param?string?$s2?second?string
?*?@return?int??return?-1,str1??str2,?str1?=?str2,?
?*????return?0,?other,?return?false
?*?@version?v0.1
?*?@create?2005-5-24
?*?@modified?2005-5-24?
?*?@author?heiyeluren?
?*/
function?strcmp1($s1,?$s2)
{
?if?(strlen($s1)???return?-1;
?if?(strlen($s1)?>?strlen($s2))
??return?1;

?for?($i=0;?$i?{
??if?($s1[$i]?==?$s2[$i])
???continue;
??else
???return?false;
?}
?return?0;
}
//?}}}


//?{{{?strchr(),?strstr(),?strpos()
/**
?*?Find?first?occurrence?of?a?string
?*
?*?@param?string?$str?parent?string
?*?@param?string?$substr?need?match?sub?string
?*?@return?int??return?find?sub?string?at?parent?string?first?place,?
?*????f?not?find,?return?false
?*?@version?v0.4
?*?@create?2005-5-24
?*?@modified?2005-5-29?
?*?@author?heiyeluren?
?*/
function?strchr1($str,?$substr)
{
?$m?=?strlen($str);
?$n?=?strlen($substr);

?if?($m???return?false;

?for?($i=0;?$i?{
??$sub?=?substr($str,?$i,?$n);
??if?(strcmp($sub,?$substr)?==?0)
???return?$i;
?}
?return?false;
}
//?}}}


//?{{{?str_replace()
/**
?*?Replace?all?occurrences?of?the?search?string?with?the?replacement?string
?*
?*?@param?string?$substr??need?replace?sub?string?variable
?*?@param?string?$newsubstr?new?sub?string
?*?@param?string?$str??operate?parent?string
?*?@return?string???return?replace?after?new?parent?string
?*?@version?v0.2
?*?@create?2005-5-24
?*?@modified?2005-5-29?
?*?@author?heiyeluren?
?*/
function?str_replace1($substr,?$newsubstr,?$str)
{
?$m?=?strlen($str);
?$n?=?strlen($substr);
?$x?=?strlen($newsubstr);

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

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


/************?以下串處理函數(shù)是PHP中沒有的，自己寫著玩?***************/

//?{{{?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??$length?need?get?string?length
?*?@return?string??return?sub?string
?*?@version?v0.1
?*?@create?2005-5-24
?*?@modified?2005-5-24?
?*?@author?heiyeluren?
?*/
function?str_insert($str,?$i,?$substr)
{

?for($j=0;?$j?{
??$startstr?.=?$str[$j];
?}

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

?return?$str;
}


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

?for?($c=($i+$j);?$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??$length?need?get?string?length
?*?@return?string??return?sub?string
?*?@version?v0.1
?*?@create?2005-5-27
?*?@modified?2005-5-27?
?*?@author?heiyeluren?
?*/
function?strcpy($s1,?$s2)
{
?if?(strlen($s1)?==?NULL)
??return;
?if?(!isset($s2))
??return;

?for?($i=0;?$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??$length?need?get?string?length
?*?@return?string??return?sub?string
?*?@version?v0.1
?*?@create?2005-5-27
?*?@modified?2005-5-27?
?*?@author??heiyeluren?
?*/
?function?strcat($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?
?*/

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

?for($i=0;?$i?{
??$c?=?ord($str[$i]);
??if?($c>31?&&?$c???$c?+=?20;
??if?($c>106?&&?$c???$c?-=?75;
??$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?{
??$c?=?ord($word);
??if?($c>106?&&?$c???$c?=?$c-20;
??if?($c>31?&&?$c???$c?=?$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?
?*/

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


如果代碼不清晰的話，建議查看一下連接，是我在blogchina的博客：

http://heiyeluren.blogchina.com/1741318.html