PHP 抓取网页图片并且另存为的实现代码
前端之家收集整理的这篇文章主要介绍了
PHP 抓取网页图片并且另存为的实现代码，
前端之家小编觉得挺不错的，现在分享给大家，也给大家做个参考。
下面是源代码，及其相关解释
<div class="codetitle"><a style="CURSOR: pointer" data="8866" class="copybut" id="copybut8866" onclick="doCopy('code8866')"> 代码如下:
<div class="codebody" id="code8866">
<?
PHP //URL是远程的完整
图片地址，不能为空,$filename 是另存为的
图片名字
//默认把
图片放在以此脚本相同的目录里
function GrabImage($url,$filename=""){
//$url 为空则返回 false;
if($url == ""){return false;}
$ext = strrchr($url,".");//得到
图片的扩展名
if($ext != ".gif" && $ext != ".jpg" && $ext != ".bmp"){echo "格式
不支持！";return false;}
if($filename == ""){$filename = time()."$ext";}//以时间戳另起名
//开始捕捉
ob_start();
readfile($url);
$img = ob_get_contents();
ob_end_clean();
$size = strlen($img);
$fp2 = fopen($filename,"a");
fwrite($fp2,$img);
fclose($fp2);
return $filename;
}
//测试
GrabImage("//www.jb51.cc/images/
logo.gif","as.gif");
?>
ob_start : 打开
输出缓冲
This function will turn output buffering on. While output buffering is active no output is sent from the script (other than headers),instead the output is stored in an internal buffer. (
输出是在内部缓冲储存)
//
readfile : 读入一个
文件并写入到
输出缓冲
返回从
文件中读入的字节数。如果出错返回 FALSE 并且除非是以 @readfile() 形式
调用，否则会
显示错误信息。
// ob_get_contents : Return the contents of the output buffer(返回
输出缓冲的
内容)
This will return the contents of the output buffer without clearing it or FALSE,if output buffering isn't active. (如果
输出缓冲没有活动（打开），则返回 FALSE)
//
ob_end_clean() : Clean (erase) the output buffer and turn off output buffering(清除
输出缓冲)
This function discards(丢弃) the contents of the topmost output buffer and turns off this output buffering.(丢弃并且关掉) If you want to further process the buffer's contents you have to call ob_get_contents() before ob_end_clean() as the buffer contents are discarded when ob_end_clean() is called. （如果要用缓冲
内容，则在清理
输出缓冲之前要先
调用 ob_get_contents()）The function returns TRUE when it successfully discarded one buffer and FALSE otherwise. Reasons for failure are first that you called the function without an active buffer or that for some reason a buffer could not be deleted (possible for special buffer).
原文链接：https://www.f2er.com/php/28690.html
