Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
666 views
in Technique[技术] by (71.8m points)

php - regex to find string within square brackets []

I want to capture the text within the square brackets in the html string below. But the regex I have below doesn't get 'image' and imagealt' seperately but returns 'image]" alt="[imagealt' instead. If I take out the alt="[imagealt]" from the string it returns as I would expect/want.

$html = '<h2>[title]</h2>
<div class="content"><img src="[image]" alt="[imagealt]" /></div>
<div class="content">[text]</div>';

preg_match_all("^[(.*)]^",$html,$fields, PREG_PATTERN_ORDER);

echo "<pre>";
print_r($fields);
echo "</pre>";


Array
(
    [0] => Array
        (
            [0] => [title]
            [1] => [image]" alt="[imagealt]
            [2] => [text]
        )

    [1] => Array
        (
            [0] => title
            [1] => image]" alt="[imagealt
            [2] => text
        )

)
See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Reply

0 votes
by (71.8m points)

your regex is being greedy. you need to stop it being greedy to do what you want. Find out a bit more about greediness here.

When a match is greedy it will ignore the first situation which satisfies the regex and will keep trying to match until it consumes as much of the input as it can.

Usually this involves adding a ? but I'm not certain in php, but you could try:

preg_match_all("^[(.*?)]^",$html,$fields, PREG_PATTERN_ORDER);

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
OGeek|极客中国-欢迎来到极客的世界,一个免费开放的程序员编程交流平台!开放,进步,分享!让技术改变生活,让极客改变未来! Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...