试试这个:

(.+?)(\.[^.]*$|$)

这将:

• 捕获以点开头的文件名(例如 .logs 是名为 .logs 的文件，而不是文件扩展名)，这在 Unix 中很常见.
• 获取除最后一个点以外的所有内容:foo.bar.jpeg 获取foo.bar.
• 处理没有点的文件:secret-letter 为您提供 secret-letter.

• Capture filenames that start with a dot (e.g. .logs is a file named .logs, not a file extension), which is common in Unix.
• Gets everything but the last dot: foo.bar.jpeg gets you foo.bar.
• Handles files with no dot: secret-letter gets you secret-letter.

注意:正如评论者 j_random_hacker 所建议的那样，这与宣传的一样，但出于可读性目的，您可能希望在前面加上锚点.

Note: as commenter j_random_hacker suggested, this performs as advertised, but you might want to precede things with an anchor for readability purposes.