php读取文件与写入文件方法实例

$filename = 'test.txt';
$filename = dirname ( __FILE__ ) . '/' . $filename;
if (file_exists ( $filename )) {
    if (! is_writable ( $filename )) {
        exit('is not writable');
    }
    $content = 'this is test words';
    $content .= "n";
    file_put_contents($filename, utf8_encode($content)); 
} else {
    exit('file is not exists');
}

$filename = 'test.txt';
        $filename = dirname ( __FILE__ ) . '/' . $filename;
        if (file_exists ( $filename )) {
            if (! is_readable ( $filename )) {
                exit('is not readable');
            }
            $contents = file_get_contents($filename);
            $contents = explode("n", $contents);
            print_r($contents);
        } else {
            exit('file is not exists');
        }

$filename = 'test.txt';
$filename = dirname ( __FILE__ ) . '/' . $filename;
if (file_exists ( $filename )) {
    if (! is_readable ( $filename )) {
        exit('is not readable');
    }
    $handle = fopen ( $filename, "rb" );
    $contents = fread($handle, filesize ($filename));
    //$contents = stream_get_contents($handle); // 也可以用方法替换上一行
    $contents = explode("n", $contents);
    fclose ( $handle );
    print_r($contents);
} else {
    exit('file is not exists');
}

<?php
$url = “http://www.111cn.net”;
$fileExists = @file_get_contents($url, null, null, -1, 1) ? true : false;
echo $fileExists; //返回1，就说明文件存在。
?>

//php判断远程文件是否存在
function url_exists($url){
    $handle=curl_init($url);
    if(false===$handle){
  return false;
    }
    curl_setopt($handle,CURLOPT_HEADER,false);
    curl_setopt($handle,CURLOPT_FAILONERROR,true);
    curl_setopt($handle,CURLOPT_NOBODY,true);
    curl_setopt($handle,CURLOPT_RETURNTRANSFER,false);
    $connectable=curl_exec($handle);
 
    curl_close($handle);   
    return $connectable;
}

function file_exists($url) {
$curl = curl_init($url);
// 不取回数据
curl_setopt($curl, CURLOPT_NOBODY, true);
// 发送请求
$result = curl_exec($curl);
$found = false;
 // 如果请求没有发送失败
if ($result !== false)
{ // 再检查http响应码是否为200
 }

  $url = "http://www.111cn.net";
 
    $info = parse_url($url);
    $fp = fsockopen($info['host'], 80,$errno, $errstr, 30);
    fputs($fp,"GET {$info['path']} HTTP/1.1rn");
    fputs($fp, "Host: {$info['host']}rn");
    fputs($fp, "Connection: closernrn");
    $headers = array();
    while(!feof($fp)) {
    $line = fgets($fp);
    if($line != "rn") {
    $headers[] = $line;
    }else {
    break;
    }
    }
 
    echo "<pre>";
    print_r($headers);

  <?php
    $url = 'http://www.111cn.net';
 
    if( @fopen( $url, 'r' ) )
    {
        echo 'File Exits';
    }
    else
    {
        echo 'File Do Not Exits';
    }
    ?>

$array = array(
    array('class' => 'a', 'value' => 3),
    array('class' => 'a', 'value' => 4),
    array('class' => 'b', 'value' => 5),
    array('class' => 'b', 'value' => 6)
)

array_avg($array, 'class');//返回二维数组
array_avg($array);//返回一维数组
// 计算平均值    返回一维数组
// 参数$avgby 按照指定字段算平均值  返回二维数组
private function array_avg($array, $avgby = NULL) {
    $array_avg = array ();
    $number = count ( $array );
    foreach ( $array as $key => $value ) {
        if ($avgby) {
            $avg_key = $value[$avgby];
            $array_avg[$avg_key]['count'] ++;
            foreach ( $value as $k => $v ) {
                $array_avg[$avg_key][$k] += $v;
            }
        } else {
            foreach ( $value as $k => $v ) {
                $array_avg[$k] += $v;
            }
        }
    }
    $array = array ();
    foreach ( $array_avg as $key => $value ) {
        if ($avgby) {
            foreach ( $value as $k => $v ) {
                $array[$key][$k] = $v / $value['count'];
            }
        } else {
            $array[$key] = $value / $number;
        }
    }
    return $array;
}

<?php
$content = file_get_contents('test.html');
$url = 'http://www.111cn.net';  //要换成的新网址
$preg = '/[s]href=("|')[S]*("|')/i';
$replace = ' href="' . $url . '"';
$content = preg_replace($preg, $replace, $content);  //正则替换
create_log('newhtml', $content);  //生成新文件
?>

function create_log($filename, $text) {
       if ( strtolower(substr($filename, -4)) != 'html' ){
              $filename .= '.html';
       }
       $filename = dirname ( __FILE__ ) . '/' . $filename;
       if (!file_exists ( $filename )) {
              exec( 'touch '. $filename);
              exec( 'chmod 777 '. $filename);
       }
       $handle = fopen ( $filename, "w+b" );
       $text .= "rn";
       fwrite($handle, $text);
       fclose ( $handle );
}

$url ='http://www.111cn.net';
$body=@file_get_contents($url);
preg_match_all('/href=['"]?([^'"]*)['"]?>(.*)/i',$body,$b);
$nums = array();
foreach($b[1] as $u){
  if(in_array($u,$nums)){
  continue;
  }
  $nums[]=$u;
  $title=strip_tags($u);
  echo $title."</br>";
}

/**
  * 当前请求是否ajax请求
  *
  * @access public
  * @return bool
  */
 function isAjax()
 {
     return isset($_SERVER['HTTP_X_REQUESTED_WITH']) && strtolower($_SERVER['HTTP_X_REQUESTED_WITH']) == 'XMLHttpRequest';
 }

switch ($_SERVER['HTTP_ACCEPT']){ 
    case 'application/json, text/javascript, */*': 
        //  JSON 格式 
        break; 
    case 'text/javascript, application/javascript, */*': 
        // javascript 或 JSONP 格式 
        break; 
    case 'text/html, */*': 
        //  HTML 格式 
        break; 
    case 'application/xml, text/xml, */*': 
        //  XML 格式 
        break; 
}