正则表达式用于捕获“_”和“。”之间的单词。

Question

I would like to use a regex to find the word between _ and . in the filename.

Example: If the filename reads ---- abc_resend.zip

I would like my pattern to return "resend" .

I tried using the following pattern: "\\_([az]*)\\." Result: _resend .

Tried the following pattern to exclude: "(?:\\\\_)([az]*)(?:\\\\.) and am still getting the same result: _resend .

What am I doing wrong? Please help.

Answer 1

The issue is that you are looking for a regular expression which matches this certain pattern. I am not sure which language you are writing in, but you want to get this result and then use some kind of strip method in order to remove those two characters from the outside. You're going to get this result because you're looking for it: the next step is since you always know what you're gonna get, to use a strip method to remove the rest. If you let me know which language you are using, I can help you track down the specific syntax.

Answer 2

. is a special character in RegEx so you need to escape it with a \\ if you want to match a . character. Try this: _([az]*)\\.

Answer 3

You can solve your problem using pattern with this regex _(\\w+)\\. :

String str = "abc_resend.zip";
Pattern pattern = Pattern.compile("_(\\w+)\\.");
Matcher matcher = pattern.matcher(str);

while (matcher.find()) {
    System.out.println(matcher.group(1));
}

Output

resend