PHP file_exists 返回 true，但 createimagefromjpeg 运行错误

Question

我有一个非常奇怪的错误！

这是我的代码：

if (file_exists($this->template->large_image_location)) {
    $tmp_src = imagecreatefromjpeg($this->template->large_image_location);  
    //work with $tmp_src
} else {
    //no picture there                      
}

我无法重现该错误，但某些用户说他们收到以下错误消息：

错误异常 [警告]：
imagecreatefromjpg（/srv/.../.../.../th_vorschau_123.jpg）： 无法打开流： 没有这样的文件或目录！

为什么我甚至会收到此错误？我在尝试加载图像之前用file_exists证明文件！

Answer 1

格拉维奇是对的。但有时realpath()会导致问题。因此，请使用此功能。[已测试]

    <?php
function truepath($path){
    // whether $path is unix or not
    $unipath=strlen($path)==0 || $path{0}!='/';
    // attempts to detect if path is relative in which case, add cwd
    if(strpos($path,':')===false && $unipath)
        $path=getcwd().DIRECTORY_SEPARATOR.$path;
    // resolve path parts (single dot, double dot and double delimiters)
    $path = str_replace(array('/', '\'), DIRECTORY_SEPARATOR, $path);
    $parts = array_filter(explode(DIRECTORY_SEPARATOR, $path), 'strlen');
    $absolutes = array();
    foreach ($parts as $part) {
        if ('.'  == $part) continue;
        if ('..' == $part) {
            array_pop($absolutes);
        } else {
            $absolutes[] = $part;
        }
    }
    $path=implode(DIRECTORY_SEPARATOR, $absolutes);
    // resolve any symlinks
    if(file_exists($path) && linkinfo($path)>0)$path=readlink($path);
    // put initial separator that could have been lost
    $path=!$unipath ? '/'.$path : $path;
    return $path;
}
if (truepath('redarrowdown.gif')){
    $tmp_src = imagecreatefromjpeg(truepath('redarrowdown.gif'));
    //work with $tmp_src
    echo "success";
}
else
{
    echo "fails";
    //no picture there
}