str_replace
resubmitting updated function in re:#76975
<?php
function asc_shift($str,$offset=0) {
$new = '';
for ($i = 0; $i < strlen($str); $i++)
$new .= chr(ord($str[$i])+$offset);
return $new;
}
?>
because as of PHP 6, $str{$i} is deprecated.
str_rot13
(PHP 4 >= 4.2.0, PHP 5)
str_rot13 — 문자열에 rot13 변환을 수행합니다.
설명
string str_rot13
( string $str
)
str 인자에 ROT13 인코딩을 수행하여, 결과 문자열을 반환합니다. ROT13 인코딩은 단순히 알파벳의 모든 문자를 13자리 쉬프트하고, 나머지 문자는 그대로 놔둡니다. 인코딩과 디코딩은 동일한 함수로 이루어집니다. 인코드한 문자열을 인자로 넘기면 원래 버전을 반환합니다.
Example#1 str_rot13() 예제
<?php
echo str_rot13('PHP 4.3.0'); // CUC 4.3.0
?>
Note: PHP 4.3.0까지 이 함수에 버그가 있었습니다. 이 이전에는, str 도 참조로 넘긴 것처럼 변경했습니다.
add a note
User Contributed Notesstr_rot13
grawity+phpnet at gmail dot com
31-Dec-2007 05:39
31-Dec-2007 05:39
nick at lazy-river dot net
08-Aug-2007 09:01
08-Aug-2007 09:01
This is recursive function to shift the component letters of a string left or right in the ascii table.
I've left it simple as it suits my needs, but you may want to include error checking for a null string and also put bounds in place, or make it actually rotate around the whole character set rather than just shifting the string up or down.
function asc_shift($string, $amount) {
$key = substr($string, 0, 1);
if(strlen($string)==1) {
return chr(ord($key) + $amount);
} else {
return chr(ord($key) + $amount) . asc_shift(substr($string, 1, strlen($string)-1), $amount);
}
}
For example:
<?php
echo asc_shift("TESTING12345@", 5);
?>
shifts every character up 5 ascii positions, resulting in this string:
YJXYNSL6789:E
In reverse:
<?php
echo asc_shift("YJXYNSL6789:E", -5);
?>
shifts every character down 5 ascii positions, resulting in this string:
TESTING12345@
arwab at surrealwebs dot com
11-Jul-2007 01:11
11-Jul-2007 01:11
here's my rot function, it works anyway
<?php
/**
* preforms the rotation algorithm on the passed in string
*/
function _rot( $str , $dist=13 ){
if( !is_numeric($dist) || $dist < 0){
$dist = 13;
}
$u_lower = 65; $u_upper = 90;
$l_lower = 97; $l_upper = 122;
$char_count = ($u_upper - $u_lower) +1;
while( $dist > $char_count ){
$dist -= $char_count;
}
$newstr = '';
for( $i=0; $i<strlen($str); ++$i){
$c = ord($str[$i]);
/*
* Check if the character is within the bounds of our function (a-zA-z)
* if not it gets tacked on to the string as is and we move on to the
* next one.
*/
if( $c<$u_lower || $c>$l_upper || ( $c>$u_upper && $c <$l_lower ) ){
$newstr .= chr($c);
continue;
}
$lower = ( $c<=$u_upper?$u_lower:$l_lower);
$upper = ( $c<=$u_upper?$u_upper:$l_upper);
$c += $dist;
if( $c > $upper){
$c = (($c - $upper) + ($lower-1));
}
$newstr .= chr($c);
}
return $newstr;
}
?>
electro at whatever dot com
31-May-2007 12:21
31-May-2007 12:21
<?php
/**
* Rotate each string characters by n positions in ASCII table
* To encode use positive n, to decode - negative.
* With n = 13 (ROT13), encode and decode n can be positive.
*
* @param string $string
* @param integer $n
* @return string
*/
function rotate($string, $n) {
$length = strlen($string);
$result = '';
for($i = 0; $i < $length; $i++) {
$ascii = ord($string{$i});
$rotated = $ascii;
if ($ascii > 64 && $ascii < 91) {
$rotated += $n;
$rotated > 90 && $rotated += -90 + 64;
$rotated < 65 && $rotated += -64 + 90;
} elseif ($ascii > 96 && $ascii < 123) {
$rotated += $n;
$rotated > 122 && $rotated += -122 + 96;
$rotated < 97 && $rotated += -96 + 122;
}
$result .= chr($rotated);
}
return $result;
}
$enc = rotate('string', 6);
echo "Encoded: $enc<br/>\n";
echo 'Decoded: ' . rotate($enc, -6);
?>
maximius at gmail dot com
25-May-2007 04:30
25-May-2007 04:30
Perhaps someone will find this useful ;)
<?
function rotN($s, $n){
$s2 = "";
for($i = 0; $i < strlen($s); $i++){
$char2 = $char = ord($s{$i});
$cap = $char & 32;
$char &= ~ $cap;
$char = $char > 64 && $char < 123 ? (($char - 65 + $n) % 26 + 65) : $char;
$char |= $cap;
if($char < 65 && $char2 > 64 || ($char > 90 && $char < 97 && ($char2 < 91 || $char2 > 96))) $char += 26;
else if($char > 122 && $char2 < 123) $char -= 52;
if(strtoupper(chr($char2)) === chr($char2)) $char = strtoupper(chr($char)); else $char = strtolower(chr($char));
$s2 .= $char;
}
return $s2;
}
?>
It takes any string, $s, and any ROT value, $n. Just like str_rot13, it's both an encoder and decoder. To decode an encoded string, just pass -$n instead of $n.