php中str_replace替换实例讲解_php技巧_

 str_replace(find,replace,string,count)

 echo str_replace(array("m","i"),array("n","z"),"my name is jim!") echo str_replace(array('m','i'),'n',"my name is jim!"); $vowels = array("a", "e", "i", "o", "u", "A", "E", "I", "O", "U"); $onlyconsonants = str_replace($vowels, "","Hello World of PHP"); echo $onlyconsonants;

    ','>',$string);     $string = str_replace("{",'',$string);     $string = str_replace('}','',$string);     $string = str_replace('','',$string);     return $string;     }     ?>      $val) $string[$key] = new_addslashes($val);     return $string;     }     ?>      -1) ? $safestep : 1;     if($safestep == 1){     $str = preg_replace("#script:#i", "ｓｃｒｉｐｔ：", $str);     $str = preg_replace("#<[/]{0,1}(link|meta|ifr|fra|scr)[^>]*>#isU", '', $str);     $str = preg_replace("#[ ]{1,}#", ' ', $str);     return $str;     }else if($safestep == 2){     $str = addslashes(htmlspecialchars(stripslashes($str)));     $str = preg_replace("#eval#i", 'ｅｖａｌ', $str);     $str = preg_replace("#union#i", 'ｕｎｉｏｎ', $str);     $str = preg_replace("#concat#i", 'ｃｏｎｃａｔ', $str);     $str = preg_replace("#--#", '－－', $str);     $str = preg_replace("#[ ]{1,}#", ' ', $str);     return $str;     }else{     return $str;     }     }     ?>     /','',$text);            //完全过滤js            $text = preg_replace('//','',$text);            $text =  str_replace('[','[',$text);            $text = str_replace(']',']',$text);            $text =  str_replace('|','|',$text);            //过滤换行符            $text = preg_replace('/ ? /','',$text);            //br            $text =  preg_replace('//i','[br]',$text);            $text = preg_replace('/([br]s*){10,}/i','[br]',$text);            //过滤危险的属性，如：过滤on事件lang js            while(preg_match('/(<[^><]+)(lang|on|action|background|codebase|dynsrc|lowsrc)[^><]+/i',$text,$mat)){                $text=str_replace($mat[0],$mat[1],$text);            }            while(preg_match('/(<[^><]+)(window.|javascript:|js:|about:|file:|document.|vbs:|cookie)([^><]*)/i',$text,$mat)){                $text=str_replace($mat[0],$mat[1].$mat[3],$text);            }            if( empty($allowTags) ) { $allowTags = self::$htmlTags['allow']; }            //允许的HTML标签            $text =  preg_replace('/<('.$allowTags.')( [^><[]]*)>/i','[12]',$text);            //过滤多余html            if ( empty($banTag) ) { $banTag = self::$htmlTags['ban']; }            $text =  preg_replace('/<]*>/i','',$text);            //过滤合法的html标签            while(preg_match('/<([a-z]+)[^><[]]*>[^><]*/i',$text,$mat)){                $text=str_replace($mat[0],str_replace('>',']',str_replace('<','[',$mat[0])),$text);            }            //转换引号            while(preg_match('/([[^[]]*=s*)("|')([^2=[]]+)2([^[]]*])/i',$text,$mat)){                $text=str_replace($mat[0],$mat[1].'|'.$mat[3].'|'.$mat[4],$text);            }            //空属性转换            $text =  str_replace('''','||',$text);            $text = str_replace('""','||',$text);            //过滤错误的单个引号            while(preg_match('/[[^[]]*("|')[^[]]*]/i',$text,$mat)){                $text=str_replace($mat[0],str_replace($mat[1],'',$mat[0]),$text);            }            //转换其它所有不合法的 < >            $text =  str_replace('<','<',$text);            $text = str_replace('>','>',$text);            $text = str_replace('"','"',$text);            //反转换            $text =  str_replace('[','<',$text);            $text =  str_replace(']','>',$text);            $text =  str_replace('|','"',$text);            //过滤多余空格            $text =  str_replace('  ',' ',$text);            return $text;        }     ?>             // note that you have to handle splits with , , and later since they *are* allowed in some          // inputs        $val = preg_replace('/([x00-x08,x0b-x0c,x0e-x19])/', '', $val);        // straight replacements, the user should never need these since they're normal characters        // this prevents like         $search = 'abcdefghijklmnopqrstuvwxyz';        $search .= 'ABCDEFGHIJKLMNOPQRSTUVWXYZ';        $search .= '1234567890!@#$%^&*()';        $search .= '~`";:?+/={}[]-_|'';        for ($i = 0; $i < strlen($search); $i++) {            // ;? matches the ;, which is optional            // 0{0,7} matches any padded zeros, which are optional and go up to 8 chars            // @ @ search for the hex values            $val = preg_replace('/(&#[xX]0{0,8}'.dechex(ord($search[$i])).';?)/i', $search[$i], $val);//with a ;            // @ @ 0{0,7} matches '0' zero to seven times            $val = preg_replace('/(�{0,8}'.ord($search[$i]).';?)/', $search[$i], $val); // with a ;        }        // now the only remaining whitespace attacks are , , and         $ra1 = Array('javascript', 'vbscript', 'expression', 'applet', 'meta', 'xml', 'blink', 'link', 'style', 'script', 'embed', 'object', 'iframe', 'frame', 'frameset', 'ilayer', 'layer', 'bgsound', 'title', 'base');        $ra2 = Array('onabort', 'onactivate', 'onafterprint', 'onafterupdate', 'onbeforeactivate', 'onbeforecopy', 'onbeforecut', 'onbeforedeactivate', 'onbeforeeditfocus', 'onbeforepaste', 'onbeforeprint', 'onbeforeunload', 'onbeforeupdate', 'onblur', 'onbounce', 'oncellchange', 'onchange', 'onclick', 'oncontextmenu', 'oncontrolselect', 'oncopy', 'oncut', 'ondataavailable', 'ondatasetchanged', 'ondatasetcomplete', 'ondblclick', 'ondeactivate', 'ondrag', 'ondragend', 'ondragenter', 'ondragleave', 'ondragover', 'ondragstart', 'ondrop', 'onerror', 'onerrorupdate', 'onfilterchange', 'onfinish', 'onfocus', 'onfocusin', 'onfocusout', 'onhelp', 'onkeydown', 'onkeypress', 'onkeyup', 'onlayoutcomplete', 'onload', 'onlosecapture', 'onmousedown', 'onmouseenter', 'onmouseleave', 'onmousemove', 'onmouseout', 'onmouseover', 'onmouseup', 'onmousewheel', 'onmove', 'onmoveend', 'onmovestart', 'onpaste', 'onpropertychange', 'onreadystatechange', 'onreset', 'onresize', 'onresizeend', 'onresizestart', 'onrowenter', 'onrowexit', 'onrowsdelete', 'onrowsinserted', 'onscroll', 'onselect', 'onselectionchange', 'onselectstart', 'onstart', 'onstop', 'onsubmit', 'onunload');        $ra = array_merge($ra1, $ra2);        $found = true; // keep replacing as long as the previous round replaced something        while ($found == true) {            $val_before = $val;            for ($i = 0; $i < sizeof($ra); $i++) {                $pattern = '/';                for ($j = 0; $j < strlen($ra[$i]); $j++) {                    if ($j > 0) {                        $pattern .= '(';                        $pattern .= '(&#[xX]0{0,8}([9ab]);)';                        $pattern .= '|';                        $pattern .= '|(�{0,8}([9|10|13]);)';                        $pattern .= ')*';                    }                    $pattern .= $ra[$i][$j];                }                $pattern .= '/i';                $replacement = substr($ra[$i], 0, 2).''.substr($ra[$i], 2); // add in <> to nerf the tag                $val = preg_replace($pattern, $replacement, $val); // filter out the hex tags                if ($val_before == $val) {                    // no replacements were made, so exit the loop                    $found = false;                }            }        }        return $val;     }     ?>