使用正则表达式检查 PHP 中的文件扩展名
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Checking for file-extensions in PHP with Regular expressions
提问by Vordreller
I'm reading all the files in a single directory and I want to filter on JPG,JPEG,GIF and PNG.
我正在读取单个目录中的所有文件，我想过滤 JPG、JPEG、GIF 和 PNG。
Both capital and small letters. Those are the only files to be accepted.
大写和小写。这些是唯一被接受的文件。
I am currently using this:
我目前正在使用这个：
$testPics = takeFiles($picsDir, "([^\s]+(?=\.(jpg|JPG|jpeg|JPEG|png|PNG|gif|GIF))\.)");
and the function takeFiles looks like this:
函数 takeFiles 看起来像这样：
function takerFiles($dir, $rex="") {
$dir .= "/";
$files = array();
$dp = opendir($dir);
while ($file = readdir($dp)) {
if ($file == '.') continue;
if ($file == '..') continue;
if (is_dir($file)) continue;
if ($rex!="" && !preg_match($rex, $file)) continue;
$files[] = $file;
}
closedir($dp);
return $files;
}
And it always returns nothing. So something must be wrong with my regex code.
它总是不返回任何内容。所以我的正则表达式代码一定有问题。
回答by
I think something is wrong with your regex. Try testing regexes here first: https://www.regexpal.com/
我认为您的正则表达式有问题。首先在这里测试正则表达式：https: //www.regexpal.com/
I think this one might work for you:
我认为这个可能对你有用：
/^.*\.(jpg|jpeg|png|gif)$/i
/^.*\.(jpg|jpeg|png|gif)$/i
Note the /i at the end - this is the "case insensitive" flag, saves you having to type out all permutations :)
注意最后的 /i - 这是“不区分大小写”的标志，让您不必输入所有排列:)
回答by Eran Galperin
回答by smack0007
Is there any reason you don't want to use scandirand pathinfo?
有什么理由不想使用scandirandpathinfo吗？
public function scanForFiles($path, array $exts)
{
$files = scanDir($path);
$return = array();
foreach($files as $file)
{
if($file != '.' && $file != '..')
{
if(in_array(pathinfo($file, PATHINFO_EXTENSION), $exts))) {
$return[] = $file;
}
}
}
return $return;
}
So you could also check if the file is a directory and do a recursive call to scan that directory. I wrote the code in haste so might not be 100% correct.
因此，您还可以检查文件是否为目录并执行递归调用以扫描该目录。我匆忙编写了代码，所以可能不是 100% 正确。
回答by Rodrigo
This works out for me
这对我有用
$string = "your-file-name.jpg";
preg_match("/\b(\.jpg|\.JPG|\.png|\.PNG|\.gif|\.GIF)\b/", $string, $output_array);
Best.
最好的事物。
回答by angus
You should put slashes around your regexp. -> "/(...)/"
你应该在你的正则表达式周围加上斜线。-> "/(...)/"
回答by ringmaster
There are a few ways of doing this.
有几种方法可以做到这一点。
Have you tried glob()?:
你试过glob()吗？：
$files = glob("{$picsDir}/*.{gif,jpeg,jpg,png}", GLOB_BRACE);
Have you considered pathinfo()?:
你考虑过pathinfo()吗？：
$info = pathinfo($file);
switch(strtolower($info['extension'])) {
case 'jpeg':
case 'jpg':
case 'gif':
case 'png':
$files[] = $file;
break;
}
If you're insistant upon using the regular expression, there's no need to match the whole filename, just the extension. Use the $token to match the end of the string, and use the iflag to denote case-insensitivity. Also, don't forget to use a delimiter in your expression, in my case "%":
如果您坚持使用正则表达式，则无需匹配整个文件名，只需匹配扩展名。使用$标记来匹配字符串的结尾，并使用i标志来表示不区分大小写。另外，不要忘记在表达式中使用分隔符，在我的例子中是“%”：
$rex = '%\.(gif|jpe?g|png)$%i';
回答by zeros-and-ones
Here are two different ways to compile an array of files by type (conf for demo) from a target directory. I'm not sure which is better performance wise.
这里有两种不同的方法可以从目标目录中按类型（用于演示的 conf）编译文件数组。我不确定哪个更好的性能明智。
$path = '/etc/apache2/';
$conf_files = [];
// Remove . and .. from the returned array from scandir
$files = array_diff(scandir($path), array('.', '..'));
foreach($files as $file) {
if(in_array(pathinfo($file, PATHINFO_EXTENSION), ['conf'])) {
$conf_files[] = $file;
}
}
return $conf_files;
This will return the full file path not just the file name
这将返回完整的文件路径，而不仅仅是文件名
return $files = glob($path . '*.{conf}',GLOB_BRACE);
