dspld86684 2013-07-08 06:14
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关于此脚本中使用的函数[关闭]

I was making a script for remote upload files to my server and here the code. BTW i took it from a site. I didn't post the site name or it might b considered as spam or something. Its about downloading remote files into our server. 

<?php

if (isset($_POST['myupload']))    
{

    $links_list = $_POST['upload'];
    $incr = 0;
    $links = explode("
",$links_list);

    define('BUFSIZ', 4095);

    for ( $incr == 0 ; $incr < count($links) ; $incr++ )
    {
        $url = $links[$incr];
        $rfile = fopen($url, 'r');
        $lfile = fopen(basename($url), 'wb');
        while(!feof($rfile))
            fwrite($lfile, fread($rfile, BUFSIZ), BUFSIZ);
        fclose($rfile);
        fclose($lfile);
    }
}
?> 

    <script type="text/javascript"></script>
</head>    
<body>
    <div id="upload_box">
        <form action="" method="post">   
            <textarea name="upload" cols=80 rows=20></textarea>
            <input type="submit" name="myupload" value="Upload Files">
        </form>

I want to ask few things about this script.

  • $lfile = fopen(basename($url), 'wb') < what does this code do ?

  • fwrite($lfile, fread($rfile, BUFSIZ), BUFSIZ); < and what about this code ?

I know am asking a foolish question but hope you guys could shed some light on that for me.

  • 写回答

3条回答 默认 最新

  • duancong7358 2013-07-08 06:22
    关注
    $lfile = fopen(basename($url), 'wb')

    fopen: Function that opens a file and returns a handle that can be used to read/write that file, depending on the second argument (explained below).

    basename: Function that strips the path from the file name, leaving just the name part. For example: basename('http://foo.com/bar.txt') would return bar.txt

    'wb': This tells fopen how to open the file: w means open it for writing, b means open it for binary access, which just means don't do any funky line ending translation (only really useful on Windows).

    $lfile: This is the handle to the file that will be used later to write to it.

    fwrite($lfile, fread($rfile, BUFSIZ), BUFSIZ);

    fwrite: Writes data to a previously opened file handle ($lfile in this case)

    fread: Reads data from a file.

    BUFSIZ: I'm assuming this is a constant defined somewhere. Regardless, the 3rd parameter to fwrite specifies how many bytes to write to the file, and the 2nd parameter to fread specifies how many bytes to read. In this case, they are both the same.

    This kind of operation is sometimes known as a buffered or block copy.

    Broken apart it would look something like this:

    $data = fread($rfile, BUFSIZ);
fwrite($lfile, $data, BUFSIZ);

    Hope that helps!

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