php - PHP正则表达式，如何匹配包含[符号的第一部分？

Question

我整个早上都试图搜索这个答案，但没有运气，我想做的就是匹配 [幻灯片或 [图库与包含的 [ 括号..

代码如下。

$gallery = get_post_meta($post->ID, 'gallery', true);


if (preg_match("|^/[slideshow", $gallery)) {
    echo "Slideshow was forund";
} else if (preg_match("|^/[nggallery", $gallery)) {
   echo "Gallery was found";
} else {
   echo "No Match found - No Meta Data available"; 
}

我用过的正则表达式，我虽然会这样工作。搜索字符串的开头，使用 / 将避免 [ 被用作正则表达式的一部分并成为搜索的一部分，

正则表达式不是我的事..虽然我读得越多，它就变得更清晰了..

Answer 1

The escape character is \ not /. Furthermore, you need to end the regex with the same delimiter as at the start of the regex. So your code will need to be something like this:

preg_match("|^\[slideshow|", $gallery)

Answer 2

if (preg_match("/^\[slideshow/", $gallery)) {
    echo "Slideshow was forund";
} else if (preg_match("/^\[nggallery/", $gallery)) {
   echo "Gallery was found";
} else {
   echo "No Match found - No Meta Data available"; 
}

Changes made:

The [ needs to be escaped as its a metachar, the escape char to be used is \. Also preg_match expects its first argument(regex) to be delimited between suitable char. So you can do:

preg_match("/^\[slideshow/", $gallery)

or

preg_match("|^\[slideshow|", $gallery)