php简单压缩英文字符串的代码

<?php 
//replacement来自上个版本的加密替换 
function compress_func($match) {return strlen($match[0]).$match[0]{0};} 
function uncompress_func($match) {return str_repeat($match[2], $match[1]);} 
function compress($str) { 
  $i = 0; 
  $pattern = array(); 
  while(isset($replacement{$i})) array_push($pattern, "/".$replacement{$i++}."{2,}/"); 
        return preg_replace_callback($pattern, "compress_func", $str); 
    } 

function uncompress($str) { 
  return preg_replace_callback("/(d+)(w)/", "uncompress_func", $str); 
} 
?>

#!/bin/awk 
function compress(str, _ARGVEND_, str_out, str_len, i, s, l) { 
    str_out = ""; 
    str_len = length(str); 
    s = ""; 
    l = 1; 
    for(i =1; i <= str_len; i++) { 
        if(substr(str, i, 1) == s) l++; 
        else { 
            if(s != "") { 
                if(l > 1) str_out=str_out""l 
                str_out=str_out""s; 
            } 
            s = substr(str, i, 1); 
            l = 1; 
        } 
    } 
    return str_out; 
} 
function uncompress(str, _ARGVEND_, str_out, str_len, i, c) { 
    str_out = ""; 
    str_len = length(str); 
    for(i =1; i <= str_len; i++) { 
        c = 0; 
        while(substr(str, i, 1)~/[0-9]/) { 
            c = c*10+substr(str, i, 1); 
            i++; 
        } 
        if(c < 1) c = 1; 
        while(c--) str_out = str_out""substr(str, i, 1); 
    } 
    return str_out; 
}