Question

所以根据这个：

http://php.net/manual/en/function.getimagesize.php

如果无法访问文件名图像，或者它无效图片，getimagesize（）将生成级别E_WARNING的错误。上读取错误，getimagesize（）将生成级别为E_NOTICE的错误。

但是当我尝试getimagesize('http://www.stackoverflow.com')时，即使网址不是有效图片，也不会产生错误或警告

当我尝试echo getimagesize('http://www.stackoverflow.com') === FALSE时，它返回1表示getimagesize（）返回布尔值false ...

这是否意味着我在传入URL时不必担心错误，而这实际上是对getimagesize（）的有效使用？

Answer 1

ini_set('display_errors', 1);
error_reporting(E_ALL);

然后你会看到警告信息。

Answer 2

这是代码

来自用户贡献james dot relyea at zifiniti dot com

的参考http://php.net/manual/en/function.getimagesize.php

<?php
// Retrieve JPEG width and height without downloading/reading entire image.
function getjpegsize($img_loc) {
    $handle = fopen($img_loc, "rb") or die("Invalid file stream.");
    $new_block = NULL;
    if(!feof($handle)) {
        $new_block = fread($handle, 32);
        $i = 0;
        if($new_block[$i]=="\xFF" && $new_block[$i+1]=="\xD8" && $new_block[$i+2]=="\xFF" && $new_block[$i+3]=="\xE0") {
            $i += 4;
            if($new_block[$i+2]=="\x4A" && $new_block[$i+3]=="\x46" && $new_block[$i+4]=="\x49" && $new_block[$i+5]=="\x46" && $new_block[$i+6]=="\x00") {
                // Read block size and skip ahead to begin cycling through blocks in search of SOF marker
                $block_size = unpack("H*", $new_block[$i] . $new_block[$i+1]);
                $block_size = hexdec($block_size[1]);
                while(!feof($handle)) {
                    $i += $block_size;
                    $new_block .= fread($handle, $block_size);
                    if($new_block[$i]=="\xFF") {
                        // New block detected, check for SOF marker
                        $sof_marker = array("\xC0", "\xC1", "\xC2", "\xC3", "\xC5", "\xC6", "\xC7", "\xC8", "\xC9", "\xCA", "\xCB", "\xCD", "\xCE", "\xCF");
                        if(in_array($new_block[$i+1], $sof_marker)) {
                            // SOF marker detected. Width and height information is contained in bytes 4-7 after this byte.
                            $size_data = $new_block[$i+2] . $new_block[$i+3] . $new_block[$i+4] . $new_block[$i+5] . $new_block[$i+6] . $new_block[$i+7] . $new_block[$i+8];
                            $unpacked = unpack("H*", $size_data);
                            $unpacked = $unpacked[1];
                            $height = hexdec($unpacked[6] . $unpacked[7] . $unpacked[8] . $unpacked[9]);
                            $width = hexdec($unpacked[10] . $unpacked[11] . $unpacked[12] . $unpacked[13]);
                            return array($width, $height);
                        } else {
                            // Skip block marker and read block size
                            $i += 2;
                            $block_size = unpack("H*", $new_block[$i] . $new_block[$i+1]);
                            $block_size = hexdec($block_size[1]);
                        }
                    } else {
                        return FALSE;
                    }
                }
            }
        }
    }
    return FALSE;
}
?>

PHP getimagesize（）返回值和错误

2 个答案: