没有单词匹配的正则表达式

Question

I have this expression:

-a bp cd 4 -6 3 -n sig3 -p 0.5 0.7

I want to match all from -a to -n . This means that the prefix and suffix are: - with one letter.

I have a start with: (?<=-a )(?<ida>[^-]*)

But i need to exclude also the letter.

Note that the -n can be any other letter with - before it and know at run time only.

How should I do that?

Thanks to all the Answers, i finally cracked it:
(?<=-a )(?.*?(?=-[az]|$))

Answer 1

You can do it like this:

(?<=-a )(?>[^ ]+| (?!-n))*(?= -n)

The interest of this expression is to avoid lazy quantifiers and to trim spaces at the begining and at the end.

Details:

(?<=-a )          # preceded by `-a `
(?>               # open an atomic group (non-capturing)
    [^ ]+         # all that is not a space
  |               # or
    [ ](?!-n)     # a space not followed by `-n`
)*                # repeat the group zero or more times
(?= -n)           # check if ` -n` follows

Answer 2

If I understood you correctly, your pattern is:

• '-a' followed by
• anything that is not a dash [^-] or a dash followed by a character that is not a letter -[^az] repeated one or more times, followed by
• a dash and a letter -[az]

This regex should do it:

(?<=-a)([^-]|-[^a-z])+(?=-[a-z])