如何将 PHP 的 eregi 更改为 preg_match
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How to change PHP's eregi to preg_match
提问by JasonDavis
Possible Duplicate:
How can I convert ereg expressions to preg in PHP?
I need help, below is a small VERY basic regex to somewhat validate an email, I do realize it does not work the greatest but for my needs it is ok for now.
我需要帮助，下面是一个很小的非常基本的正则表达式，可以在一定程度上验证电子邮件，我确实意识到它不起作用，但对于我的需要，现在还可以。
It currently uses PHP's eregi functionwhich php.net says is now a depreciated function and I should use preg_matchinstead, simply replacing erei with preg_match does not work, can someone show me how to make it work?
它目前使用 PHP 的eregi 函数，php.net 说它现在是一个折旧的函数，我应该使用preg_match，简单地用 preg_match 替换 erei 不起作用，有人可以告诉我如何使它工作吗？
function validate_email($email) {
if (!eregi("^[[:alnum:]][a-z0-9_.-]*@[a-z0-9.-]+\.[a-z]{2,4}$", $email)) {
echo 'bad email';
} else {
echo 'good email';
}
}
function validate_email($email) {
if (!preg_match("^[[:alnum:]][a-z0-9_.-]*@[a-z0-9.-]+\.[a-z]{2,4}$", $email)) {
echo 'bad email';
} else {
echo 'good email';
}
}
回答by Amber
Perl-style regex patterns always need to be delimited. The very first character in the string is considered the delimiter, so something like this:
Perl 风格的正则表达式模式总是需要被分隔。字符串中的第一个字符被认为是分隔符，所以是这样的：
function validate_email($email) {
if (!preg_match("/^[[:alnum:]][a-z0-9_.-]*@[a-z0-9.-]+\.[a-z]{2,4}$/i", $email)) {
echo 'bad email';
} else {
echo 'good email';
}
}
The reason your initial attempt didn't work is because it was trying to use ^as the delimiter character but (obviously) found no matching ^for the end of the regex.
您最初的尝试无效的原因是它试图^用作分隔符，但（显然）^在正则表达式的末尾找不到匹配项。
回答by Peter Bailey
You will need to change three things
你需要改变三件事
- need to add pattern delimiters (can be any character, but most commonly a forward slash)
- [[:alnum:]] will need to be replaced with the PCRE equivalent
- The "i" in "eregi" means case-insensitive, which PCRE does with a flag, specifically the
iflag.
- 需要添加模式分隔符（可以是任何字符，但最常见的是正斜杠）
- [[:alnum:]] 将需要替换为 PCRE 等效项
- "eregi" 中的 "i" 表示不区分大小写，PCRE 使用标志，特别是
i标志。
Otherwise, the rest looks PCRE compatible (yes, that's kind of redundant =P)
否则，其余部分看起来与 PCRE 兼容（是的，这有点多余 =P）
"/^[a-z0-9][a-z0-9_.-]*@[a-z0-9.-]+\.[a-z]{2,4}$/i"
