How can I include a minus sign in this regex?

Question

I'm trying to match the following three lines:

usemtl ftw
kd 1.2 3.2 3.1
v  -12.1892 -53.4267 -276.4055

My regex matches the first two:

^(\w+) ((\S+)( \S+)*) *$

I've tried a few variants to match the negative numbers, but they just stop anything from being matched:

^(\w+) (([\S-]+)( [\S-]+)*) *$
^(\w+) (((\S|-)+)( (\S|-)+)*) *$

What am I supposed to do here? - isn't a special character in regex, is it?

Answer 1

- is only a special character in character classes [...]

Your problem comes from v -12.1892 -53.4267 -276.4055 containing 2 spaces in between v and -12.18... . Your regex only matches one.

Try this regex instead:

^(\w+)\s*((\S+)( \S+)*) *$

Although your regex could be simplified to (not sure exactly what you want to match and capture though):

^(\w+)(\s*\S+)*$

See it on http://rubular.com/r/D86njdYzJF

Answer 2

Put it first in the class: [-\\S]

Then it should work.

Answer 3

There are two spaces between v and -12.1892 that seems to be your problem. Also to use - inside a character class ie [...] you need to escape it with \\-

Answer 4

The reason why it isn't matching is because your third line has two spaces between the v and -12.1892 . Try this:

^(\\w+) +(([\\S]+)( [\\S]+)*) *$ (the added + sign allows for multiple spaces)

Here is the jsfiddle to test it: http://jsfiddle.net/xewys/

Answer 5

我能想到的与您的示例数据相匹配的最基本的正则表达式是“(\\S+\\s+)+”，但这可能不适合您 - 它似乎太通用了。