Php 上传时有没有生成随机文件名的方法？_Php_Html

Php 上传时有没有生成随机文件名的方法？

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Php 上传时有没有生成随机文件名的方法？,php,html,Php,Html,我创建了一个可以上传任何东西的网站。我的问题是我对这一切都不熟悉。我已经尝试了所有生成随机字符串的代码，但我什么都没有。下面是代码： <?php $fileName = $_FILES["file1"]["name"]; // The file name $fileTmpLoc = $_FILES["file1"]["tmp_name"]; // File in the PHP tmp folder $fileType = $_FILES["file1"]["type"]; // The

我创建了一个可以上传任何东西的网站。我的问题是我对这一切都不熟悉。我已经尝试了所有生成随机字符串的代码，但我什么都没有。下面是代码：

<?php

$fileName = $_FILES["file1"]["name"]; // The file name
$fileTmpLoc = $_FILES["file1"]["tmp_name"]; // File in the PHP tmp folder
$fileType = $_FILES["file1"]["type"]; // The type of file it is
$fileSize = $_FILES["file1"]["size"]; // File size in bytes
$fileErrorMsg = $_FILES["file1"]["error"]; // 0 for false... and 1 for true
if (!$fileTmpLoc) { // if file not chosen
    echo "ERROR: Please browse for a file before clicking the upload button.";
    exit();
}
if(move_uploaded_file($fileTmpLoc, "uploads/$fileName")) {
    echo '<a href="uploads/'.$fileName.'"><input type="button" class="button"    
    value="Download" /></a>';
} else {
    echo "move_uploaded_file function failed";
}

?>

有没有一种方法可以生成随机文件名，这样当有人上传与服务器上已有文件同名的文件时，它不会覆盖现有文件？

使用时间戳（或microtime），这样您就知道每次上传的文件都必然不同

$fileName = "image_".time();

时间戳返回自Unix纪元（1970年1月1日00:00:00 GMT）以来以秒为单位测量的当前时间

微时间 microtime（）返回当前Unix时间戳，单位为微秒。此函数仅在支持gettimeofday（）系统调用的操作系统上可用

您可以使用microtime来确保文件名是唯一的

 $file_name = "custom_name_" . microtime();

试试这个

$now=date('d/m/y');
if(move_uploaded_file($fileTmpLoc, "uploads/$now.$fileName"))

它将在文件名前面添加日期，因为文件夹限制为65535个文件，所以您需要创建子文件夹。此技术根据时间戳创建3个子文件夹（每个子文件夹有3个字符），然后创建一个随机文件名

//you can use both random and time function to get more unique no count:


 $fileName = 'mypic'.mt_rand(100000, 999999).'_'.time(). $_FILES["file1"]["name"];

use are:-
mt_rand(100000, 999999)// for randm no.
time()// for timestring
$_FILES["file1"]["name"]//also you can give your file name

为了获得更多的随机性和未来证明（因为如果您同时有多个用户上传，则使用time（）和microtime（）是很弱的）：

以及mkdir递归函数：

private function _r_mkdir($path, $mode = 0755, $recursive = true)
{
    if(empty($path)){
        return false;
    }

    if($recursive) {
        $toDo = substr($path, 0, strrpos($path, '/'));
        if($toDo !== '.' && $toDo !== '..'){
            _r_mkdir($toDo, $mode);
        }
    }

    if(!is_dir($path)){
        mkdir($path, $mode);
    }

    return true;
}

函数的作用是：根据微时间生成一个唯一的ID （以微秒为单位的当前时间）

关于uniqid函数：

仔细研究此代码。这就是你所需要的

<?php
    if (isset($_FILES["avatar"]["name"]) && $_FILES["avatar"]["tmp_name"] != "")
    {
      $fileName = $_FILES["avatar"]["name"];
      $fileTmpLoc = $_FILES["avatar"]["tmp_name"];
      $fileType = $_FILES["avatar"]["type"];
      $fileSize = $_FILES["avatar"]["size"];
      $fileError = $_FILES["avatar"]["error"];
      $kaboom = explode(".",$fileName);
      $fileExt = end($kaboom);
      list($width,$height) = getimagesize($fileTmpLoc);
      if($width < 10 || $height < 10)
      {
        header("location: ../message.php?msg=ERROR: That image has no dimensions");
        exit();  
      }
      $db_file_name = rand(100000000000,999999999999).".".$fileExt;
      if($fileSize > 5048576)
      {
        header("location: ../message.php?msg=ERROR: Your image file was larger than 1mb");
        exit();   
      }
      else if (!preg_match("/\.(gif|jpg|png)$/i", $fileName) ) 
      {
        header("location: ../message.php?msg=ERROR: Your image file was not jpg, gif or png type");
        exit();
      }
      else if ($fileErrorMsg == 1) 
      {
        header("location: ../message.php?msg=ERROR: An unknown error occurred");
        exit();
      }
      $sql = "SELECT avatar FROM users WHERE username='$log_username' LIMIT 1";
      $query = mysqli_query($db_conx,$sql);
      $row = mysqli_fetch_row($query);
      $avatar = $row[0];
      if($avatar != "")
      {
        $picurl = "../user/$log_username/$avatar"; 
        if (file_exists($picurl))
        unlink($picurl);
      }
      $moveResult = move_uploaded_file($fileTmpLoc,"../user/$log_username/$db_file_name");
      if ($moveResult != true) 
      {
        header("location: ../message.php?msg=ERROR: File upload failed");
        exit();
      }
      include_once("../php_includes/image_resize.php");
      $target_file = "../user/$log_username/$db_file_name";
      $resized_file = "../user/$log_username/$db_file_name";
      $wmax = 200;
      $hmax = 300;
      img_resize($target_file, $resized_file, $wmax, $hmax, $fileExt);
      $sql = "UPDATE users SET avatar='$db_file_name' WHERE username='$log_username' LIMIT 1";
      $query = mysqli_query($db_conx, $sql);
      mysqli_close($db_conx);
      header("location: ../user.php?u=$log_username");
      exit();
    }
    ?>

您可以使用md5（microtime（））来获得唯一的文件名，即使您一次上载多个文件我通常使用时间戳来为上载的文件命名唯一的名称。据说move\u uploaded\u file功能失败，每天只允许1个文件。。这不是个好办法。
$fileName = "image_".uniqid();

<?php
    if (isset($_FILES["avatar"]["name"]) && $_FILES["avatar"]["tmp_name"] != "")
    {
      $fileName = $_FILES["avatar"]["name"];
      $fileTmpLoc = $_FILES["avatar"]["tmp_name"];
      $fileType = $_FILES["avatar"]["type"];
      $fileSize = $_FILES["avatar"]["size"];
      $fileError = $_FILES["avatar"]["error"];
      $kaboom = explode(".",$fileName);
      $fileExt = end($kaboom);
      list($width,$height) = getimagesize($fileTmpLoc);
      if($width < 10 || $height < 10)
      {
        header("location: ../message.php?msg=ERROR: That image has no dimensions");
        exit();  
      }
      $db_file_name = rand(100000000000,999999999999).".".$fileExt;
      if($fileSize > 5048576)
      {
        header("location: ../message.php?msg=ERROR: Your image file was larger than 1mb");
        exit();   
      }
      else if (!preg_match("/\.(gif|jpg|png)$/i", $fileName) ) 
      {
        header("location: ../message.php?msg=ERROR: Your image file was not jpg, gif or png type");
        exit();
      }
      else if ($fileErrorMsg == 1) 
      {
        header("location: ../message.php?msg=ERROR: An unknown error occurred");
        exit();
      }
      $sql = "SELECT avatar FROM users WHERE username='$log_username' LIMIT 1";
      $query = mysqli_query($db_conx,$sql);
      $row = mysqli_fetch_row($query);
      $avatar = $row[0];
      if($avatar != "")
      {
        $picurl = "../user/$log_username/$avatar"; 
        if (file_exists($picurl))
        unlink($picurl);
      }
      $moveResult = move_uploaded_file($fileTmpLoc,"../user/$log_username/$db_file_name");
      if ($moveResult != true) 
      {
        header("location: ../message.php?msg=ERROR: File upload failed");
        exit();
      }
      include_once("../php_includes/image_resize.php");
      $target_file = "../user/$log_username/$db_file_name";
      $resized_file = "../user/$log_username/$db_file_name";
      $wmax = 200;
      $hmax = 300;
      img_resize($target_file, $resized_file, $wmax, $hmax, $fileExt);
      $sql = "UPDATE users SET avatar='$db_file_name' WHERE username='$log_username' LIMIT 1";
      $query = mysqli_query($db_conx, $sql);
      mysqli_close($db_conx);
      header("location: ../user.php?u=$log_username");
      exit();
    }
    ?>