php - 匹配文本文件中的数字？

Question

我想匹配文本文件中的数字并将其替换为添加到匹配数字中的新数字

似乎无法让它工作

<!---- update textfile on the server after a new order has taken place--->
<?php 


$filename = "order.txt";
$handle = fopen($filename, "r");

$Data = fread($handle, 512); 
echo $Data;
$pattern = "?P<digit>\d+";
preg_match($pattern,$Data,$matches);
print_r($matches);


fclose($handle);


$Handle = fopen($File, 'w');
fwrite($Handle, "The total Number of Apples: ".$Apples.PHP_EOL); 
fwrite($Handle, "The total Number of Bananas: ".$Bananas.PHP_EOL);
fwrite($Handle, "The total Number of Oranges: ".$Oranges.PHP_EOL);

fclose($Handle); 



?>

Answer 1

正如 anubhava 在评论中所说，您必须用定界符包围您的正则表达式，/并添加括号以捕获名称组：

$pattern = "/(?P<digit>\d+)/";
preg_match($pattern, $Data, $matches);